1
|
Siegel JP. Nut factors associated with navel orangeworm, Amyelois transitella (Lepidoptera: Pyralidae) damage to pistachio (Pistacia vera) in California (2007-2017) and implication for control. J Econ Entomol 2023; 116:882-890. [PMID: 37040579 DOI: 10.1093/jee/toad051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 02/24/2023] [Accepted: 03/27/2023] [Indexed: 06/14/2023]
Abstract
Amyelois transitella is the primary pest of pistachios in California. The first A. transitella outbreak of the twenty-first century occurred in 2007 and a total of five outbreaks occurred between 2007 and 2017 (total insect damage >1%). This study used processor information to identify the nut factors associated with the outbreaks. Processor grade sheets were used to explore the relationship between the variables time of harvest, percent nut split, percent nut dark staining, percent nut shell damage, and percent adhering hull for Low Damage (82,537 loads) and High Damage years, (92,307 loads). Total insect damage (±SD) for the Low Damage years averaged 0.005 ± 0.01 and in High Damage years was three times higher, 0.015 ± 0.02. In Low Damage years the strongest correlation was between total insect damage and two variables, percent adhering hull and dark stain (0.25, 0.23) while in High Damage years the correlation between total insect damage and percent dark stain was the highest (0.32) followed by percent adhering hull (0.19). The linkage of these nut factors to insect damage suggests that outbreak prevention depends on early identification of premature hull split/breakdown in addition to the traditional emphasis on treating the standing population of A. transitella.
Collapse
Affiliation(s)
- Joel P Siegel
- USDA-ARS, San Joaquin Valley Agricultural Sciences Center, Commodity Protection and Quality Unit, 9611 South Riverbend Avenue, Parlier, CA 93648, USA
| |
Collapse
|
2
|
Siegel JP, Gilcrease G. Augmenting sanitation with insecticides to improve control of navel orangeworm (Amyelois transitella Walker) (Lepidoptera: Pyralidae) in California tree nuts. Pest Manag Sci 2022; 78:2034-2042. [PMID: 35122376 DOI: 10.1002/ps.6827] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 01/23/2022] [Accepted: 02/04/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Sanitation, consisting of eliminating unharvested nuts (mummies) that serve as both harborage and food source for navel orangeworm (Amyelois transitella), is the foundation for control in almonds and pistachios. Sometimes sanitation is ineffective and needs to be augmented. Trials in almonds and pistachios were conducted early October 2005-2006 to determine if insecticides applied postharvest could augment sanitation, and in almonds late March to early May 2016-2020 to establish their duration of control. RESULTS Early October sprays reduced adult emergence by as much as 81.5% in pistachios, but reduction was only 32.4% in almonds. Trapping before almond hull split revealed that 55% of adult emergence occurred between 15 April and 1 June, indicating that an insecticide with a six week duration of control could reduce successful oviposition and neonate establishment. Five insecticides applied from late March to early May belonging to four Insecticide Resistance Action Committee (IRAC) groups decreased survival for at least six weeks, and some lasted as long as 10 weeks. By contrast, the duration of control in contact bioassays was far shorter. CONCLUSION Insecticides applied from late March to early May successfully reduced the survival of A. transitella in almond mummies for as long as 10 weeks postapplication, and there was a positive relationship between reduction in survival and kernel damage. If these insecticides are applied during mid- to late April, postbloom and before hull split, they can substantially eliminate almond mummies as a resource for 55% of the spring flight of A. transitella.
Collapse
Affiliation(s)
- Joel P Siegel
- USDA Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, CA, USA
| | | |
Collapse
|
3
|
Van Steenwyk RA, Siegel JP, Bisabri B, Cabuslay CS, Choi JM, Steggall JW, Mace KC, Blecker SW, Poe PA, Peters-Collaer SR, Klassen P. Spray drift mitigation using opposing synchronized air-blast sprayers. Pest Manag Sci 2021; 77:895-905. [PMID: 32949089 DOI: 10.1002/ps.6094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 08/18/2020] [Accepted: 09/19/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Pesticide drift is a serious environmental and safety concern that affects all of US agriculture. A number of mitigation techniques to reduce pesticide drift have been recommended by industry, academic and government agencies. These techniques are very costly or reduce the efficacy of the pest control product and have not been implemented by US agriculture. RESULTS When using a novel spray technique (Air-in), pesticide drift was significantly reduced by between 53% and 99% at 7.6 m from the orchard drip line when compared to the grower standard. This technique not only reduced pesticide drift, but also maintained or improved the amount of pesticide residue deposited (by 0.7-2.6-fold) and the percentage pesticide coverage (by 1.0-1.4-fold) with different air-blast speed sprayers on almond, walnut and pistachio. CONCLUSION The Air-in technique shows great promise in reducing pesticide drift while maintaining or improving pesticide coverage with minimal cost to the grower.
Collapse
Affiliation(s)
- Robert A Van Steenwyk
- Department of Environmental Science Policy and Management, University of California, Berkeley, CA, USA
| | | | | | - Christian S Cabuslay
- Department of Environmental Science Policy and Management, University of California, Berkeley, CA, USA
| | - Jaimie M Choi
- Department of Environmental Science Policy and Management, University of California, Berkeley, CA, USA
| | - J W Steggall
- Department of Food and Agriculture, Sacramento, CA, USA
- Department of Land, Air, Water Resources, University of California, Davis, CA, USA
| | - Kevi C Mace
- Department of Food and Agriculture, Sacramento, CA, USA
- Department of Agricultural Resource Economics, University of California, Davis, CA, USA
| | - Steve W Blecker
- Department of Food and Agriculture, Sacramento, CA, USA
- Department of Agricultural Resource Economics, University of California, Davis, CA, USA
| | - Perry A Poe
- Department of Food and Agriculture, Sacramento, CA, USA
| | - Stephen R Peters-Collaer
- Department of Environmental Science Policy and Management, University of California, Berkeley, CA, USA
| | | |
Collapse
|
4
|
Demkovich MR, Calla B, Ngumbi E, Higbee BS, Siegel JP, Berenbaum MR. Differential regulation of cytochrome P450 genes associated with biosynthesis and detoxification in bifenthrin-resistant populations of navel orangewom (Amyelois transitella). PLoS One 2021; 16:e0245803. [PMID: 33481873 PMCID: PMC7822513 DOI: 10.1371/journal.pone.0245803] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 01/07/2021] [Indexed: 12/25/2022] Open
Abstract
Pyrethroid resistance was first reported in 2013 for the navel orangeworm, Amyelois transitella, but the genetic underpinnings of pyrethroid resistance are unknown. We investigated the role of cytochrome P450 monooxygenases (P450s) belonging to the CYP3 and CYP4 clans using colonies derived from individuals collected in 2016 from almond orchards in two counties. One colony (ALM) originated from an almond orchard in Madera County with no reported pyrethroid resistance and the second colony (R347) originated from the same Kern County orchard where pyrethroid resistance was first reported. We used high-throughput quantitative real-time PCR (qRT-PCR) analyses of 65 P450s in the CYP3 and CYP4 clans of A. transitella to identify P450s induced by bifenthrin and associated with pyrethroid resistance. Nine P450s were constitutively overexpressed in R347 compared to ALM, including CYP6AE54 (11.7-fold), belonging to a subfamily associated with metabolic pesticide detoxification in Lepidoptera and CYP4G89 (33-fold) belonging to a subfamily associated with cuticular hydrocarbon (CHC) synthesis and resistance via reduced pesticide penetrance. Cuticular hydrocarbons analysis revealed that R347 produced twice as many total CHCs in the egg and adult stages as ALM. Topical toxicity bioassays for R347 determined that egg mortality was reduced at low bifenthrin concentrations and larval mortality was reduced at high concentrations of bifenthrin compared to ALM. Our discovery of both changes in metabolism and production of CHCs for R347 have implications for the possible decreased efficacy of other classes of insecticide used to control this insect. The threat of widespread pyrethroid resistance combined with the potential for cross-resistance to develop through the mechanism of reduced penetrance warrants developing management strategies that facilitate insecticide passage across the cuticle.
Collapse
Affiliation(s)
- Mark R. Demkovich
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Bernarda Calla
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- * E-mail:
| | - Esther Ngumbi
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | | | - Joel P. Siegel
- USDA-ARS, San Joaquin Valley Agricultural Sciences Center, Parlier, California, United States of America
| | - May R. Berenbaum
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| |
Collapse
|
5
|
Calla B, Demkovich M, Siegel JP, Viana JPG, Walden KKO, Robertson HM, Berenbaum MR. Selective Sweeps in a Nutshell: The Genomic Footprint of Rapid Insecticide Resistance Evolution in the Almond Agroecosystem. Genome Biol Evol 2020; 13:5955766. [PMID: 33146372 PMCID: PMC7850051 DOI: 10.1093/gbe/evaa234] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/01/2020] [Indexed: 11/14/2022] Open
Abstract
Among the most familiar forms of human-driven evolution on ecological time scales is the rapid acquisition of resistance to pesticides by insects. Since the widespread adoption of synthetic organic insecticides in the mid-twentieth century, over 500 arthropod species have evolved resistance to at least one insecticide. Efforts to determine the genetic bases of insecticide resistance have historically focused on individual loci, but the availability of genomic tools has facilitated the screening of genome-wide characteristics. We resequenced three contemporary populations of the navel orangeworm (Amyelois transitella), the principal pest of almond orchards in California, differing in bifenthrin resistance status to examine insecticide-induced changes in the population genomic landscape of this species. We detected an exceptionally large region with virtually no polymorphisms, extending to up to 1.3 Mb in the resistant population. This selective sweep includes genes associated with pyrethroid and DDT resistance, including a cytochrome P450 gene cluster and the gene encoding the voltage-gated sodium channel para. Moreover, the sequence along the sweep is nearly identical in the genome assembled from a population founded in 1966, suggesting that the foundation for insecticide resistance may date back a half-century, when California’s Central Valley experienced massive area-wide applications of DDT for pest control.
Collapse
Affiliation(s)
- Bernarda Calla
- Department of Entomology, University of Illinois at Urbana-Champaign
| | - Mark Demkovich
- Department of Entomology, University of Illinois at Urbana-Champaign
| | - Joel P Siegel
- United States Department of Agriculture, Agricultural Research Service, Commodity Protection and Quality Research, Parlier, California
| | | | - Kim K O Walden
- Department of Entomology, University of Illinois at Urbana-Champaign
| | - Hugh M Robertson
- Department of Entomology, University of Illinois at Urbana-Champaign
| | - May R Berenbaum
- Department of Entomology, University of Illinois at Urbana-Champaign
| |
Collapse
|
6
|
Siegel JP, Strmiska MM, Walse SS. Evaluating insecticide coverage and determining its effect on the duration of control for navel orangeworm (Amyelois transitella Walker) (Lepidoptera: Pyralidae) in California almonds. Pest Manag Sci 2019; 75:2989-2995. [PMID: 30927307 DOI: 10.1002/ps.5413] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 02/05/2019] [Accepted: 03/17/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Insecticide application is essential to control navel orangeworm (Amyelois transitella) in California almonds (Prunus dulcis), but coverage is challenging. Laboratory and field trials were conducted from 2014 to 2017 to quantify insecticide deposition and duration of control. RESULTS In the laboratory for filter paper, photolysis reduced the contact toxicity of bifenthrin, and its half-life was 6.2 days. For chlorantraniliprole applied in the field, there was 87-94% less insecticide deposited in the almond suture, the most vulnerable part of the nut, than on the hull. For chlorantraniliprole, adjuvant choice (alcohol ethoxylate versus mineral oil) affected both initial insecticide deposition and half-life. Chlorantraniliprole degradation was greater at 6.1 m than at 3 m for both adjuvants assessed, whereas contact mortality was similar at both heights for the alcohol ethoxylate adjuvant. CONCLUSION The combination of photolysis and differential distribution of insecticide on the nut can account for the variable control observed in the field. This was particularly problematic in the upper canopy and adjuvant choice affected deposition and insecticide degradation. Less than 1% of the insecticide in the tank was deposited on the almond suture. These results demonstrating the fraction of the insecticide in the sprayer tank deposited on the nut target, combined with reduced coverage in the upper canopy are also applicable to the control of A. transitella in pistachio (Pistacia vera) and walnut (Juglans regia) orchards. © 2019 Society of Chemical Industry.
Collapse
Affiliation(s)
- Joel P Siegel
- USDA Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, California, USA
| | | | - Spenser S Walse
- USDA Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, California, USA
| |
Collapse
|
7
|
Siegel JP, Strmiska MM, Niederholzer FJ, Giles DK, Walse SS. Evaluating insecticide coverage in almond and pistachio for control of navel orangeworm (Amyelois transitella) (Lepidoptera: Pyralidae). Pest Manag Sci 2019; 75:1435-1442. [PMID: 30430743 DOI: 10.1002/ps.5265] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 09/29/2018] [Accepted: 11/04/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND Insecticide application is essential to control navel orangeworm (Amyelois transitella) in California almond and pistachios. Coverage is difficult because of tree height and applicator practices. Studies were conducted to characterize insecticide deposition by both ground and air, and to develop alternatives to the use of water-sensitive cards to assess spray coverage. RESULTS We used almond challenge bioassays to demonstrate that insecticide application failed first in the upper canopy (5.2-6.1 m) when application speed exceeded 2.9 kph. In pistachios, we used filter paper and insecticide extraction from hulls to demonstrate that deposition increased with application volume. Typically, in ground applications, coverage decreased with height, whereas for application by air, coverage was greatest at the top of the canopy (6 m) and decreased as the spray penetrated the canopy. In the best ground applications there was no loss over height. We were able to demonstrate a dose-response relationship for methoxyfenozide using contact toxicity bioassays. CONCLUSION Coverage was best at or below the recommended speed of 3.2 kph and improved when water volume increased. There was a 50% loss in insecticide efficacy at the height of 4-4.8 m; we suggest that future monitoring concentrate on this portion of the canopy. The best ground application provided uniform deposition throughout the canopy, whereas the applications by air were most effective in the upper canopy. The use of filter paper can provide information for chemical deposition and enable contact toxicity bioassays, whereas water-sensitive paper cannot do this. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.
Collapse
Affiliation(s)
- Joel P Siegel
- USDA Agricultural Research Service, Commodity Protection and Quarantine, San Joaquin Valley Agricultural Sciences Center, Parlier, CA, USA
| | | | - Franz Ja Niederholzer
- University of California Cooperative Extension, Farm Advisor Orchard Systems Colusa County, Colusa, CA, USA
| | - D Ken Giles
- Department of Biological and Agricultural Engineering, University of California-Davis, Davis, CA, USA
| | - Spenser S Walse
- USDA Agricultural Research Service, Commodity Protection and Quarantine, San Joaquin Valley Agricultural Sciences Center, Parlier, CA, USA
| |
Collapse
|
8
|
Bush DS, Siegel JP, Berenbaum MR. Accelerated Development and Toxin Tolerance of the Navel Orangeworm Amyelois transitella (Lepidoptera: Pyralidae) in the Presence of Aspergillus flavus. J Chem Ecol 2018; 44:1170-1177. [PMID: 30370473 DOI: 10.1007/s10886-018-1027-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 10/08/2018] [Accepted: 10/15/2018] [Indexed: 10/28/2022]
Abstract
The navel orangeworm (Amyelois transitella) and the fungus Aspergillus flavus constitute a facultative mutualism and pest complex in tree nut and fruit orchards in California. The possibility exists that the broad detoxification capabilities of A. flavus benefit its insect associate by metabolizing toxicants, including hostplant phytochemicals and pesticides. We examined this hypothesis by conducting laboratory bioassays to assess growth rates and survivorship of pyrethroid-resistant (R347) and susceptible (CPQ) larval strains on potato dextrose agar diet containing almond meal with and without two furanocoumarins, xanthotoxin and bergapten, found in several hostplants, and with and without two insecticides, bifenthrin and spinetoram, used in almond and pistachio orchards. Additionally, fungi were incubated in liquid diets containing the test chemicals, and extracts of these diets were added to almond potato dextrose agar (PDA) diets and fed to larvae to evaluate the ability of the fungus to metabolize these chemicals. Larvae consuming furanocoumarin-containing diet experienced higher mortality than individuals on unamended diets, but adding A. flavus resulted in up to 61.7% greater survival. Aspergillus flavus in the diet increased development rate > two-fold when furanocoumarins were present, demonstrating fungal enhancement of diet quality. Adding extracts of liquid diets containing xanthotoxin and fungus decreased mortality compared to xanthotoxin alone. On diets containing bifenthrin and spinetoram, however, mortality increased. These results support the hypothesis that A. flavus enhances navel orangeworm performance and contributes to detoxification of xenobiotics. Among practical implications of our findings, this mutualistic association should be considered in designing chemical management strategies for these pests.
Collapse
Affiliation(s)
- Daniel S Bush
- Department of Entomology, University of Illinois at Urbana-Champaign, 204 Morrill Hall, 505 S. Goodwin Ave, Urbana, IL, 61801, USA.
| | - Joel P Siegel
- USDA-ARS, San Joaquin Valley Agricultural Sciences Center, 9611 South Riverbend Avenue, Parlier, CA, 93648, USA
| | - May R Berenbaum
- Department of Entomology, University of Illinois at Urbana-Champaign, 204 Morrill Hall, 505 S. Goodwin Ave, Urbana, IL, 61801, USA
| |
Collapse
|
9
|
Bush DS, Lawrance A, Siegel JP, Berenbaum MR. Orientation of Navel Orangeworm (Lepidoptera: Pyralidae) Larvae and Adults Toward Volatiles Associated With Almond Hull Split and Aspergillus flavus. Environ Entomol 2017; 46:602-608. [PMID: 28379558 DOI: 10.1093/ee/nvx068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Indexed: 06/07/2023]
Abstract
The navel orangeworm Amyelois transitella (Walker, 1863, Lepidoptera: Pyralidae), a pest of California tree nuts, is associated with the fungus Aspergillus flavus, and previous research suggests these species are facultative mutualists. Because navel orangeworm larvae exhibit improved performance on diets containing this fungus, orientation toward hostplants infected with A. flavus may be adaptive. We conducted behavioral assays to determine if larvae respond to chemical cues produced by almond hull split and fungal infection. In petri dish arenas, larvae showed a preference for 1-octen-3-ol and 2-phenylethanol, volatiles characteristic of damaged plants, as well as methanolic extracts of almond meal with 1-octen-3-ol and the fungal volatile conophthorin. In contrast, larvae displayed aversion to ethyl benzoate, an inhibitor of fungal growth. When we assessed oviposition behavior relative to substrates with and without A. flavus, females laid almost twice as many eggs near inoculated surfaces. Moreover, an average of 63% of eggs laid near inoculated substrates were fertilized, compared with 24% of eggs near uninoculated sites. We also tested the hypothesis that unfertilized eggs are laid on nutrient-poor substrates to provide supplemental nutrition for larvae in an assay comparing larval survivorship in the presence and absence of unfertilized eggs. Neonates given eggs survived 2.5 times longer on an average than unprovisioned neonates (208.8 h vs. 85.2 h), indicating that this species may compensate with cannibalism for oviposition on lower-quality food sources. We conclude that larvae orient to probable host plant and fungal volatiles associated with hull split and document a possible strategy for larvae to establish on low-quality hosts.
Collapse
Affiliation(s)
- Daniel S Bush
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (; ; )
| | - Allen Lawrance
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (; ; )
| | - Joel P Siegel
- USDA-ARS, San Joaquin Valley Agricultural Sciences Center, 9611 South Riverbend Ave., Parlier, CA 93648
| | - May R Berenbaum
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (; ; )
| |
Collapse
|
10
|
Ampt EA, Bush DS, Siegel JP, Berenbaum MR. Larval Preference and Performance of Amyelois transitella (Navel Orangeworm, Lepidoptera: Pyralidae) in Relation to the Fungus Aspergillus flavus. Environ Entomol 2016; 45:155-162. [PMID: 26491042 DOI: 10.1093/ee/nvv160] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 09/16/2015] [Indexed: 06/05/2023]
Abstract
The navel orangeworm, Amyelois transitella (Walker), is a polyphagous pest of California nut crops and is responsible for extensive losses in the United States. It directly damages crops by feeding and contaminating nuts with frass and webbing and vectors saprophytic fungi that infect crops. The navel orangeworm is commonly associated with Aspergillus species, including the toxigenic Aspergillus flavus, which causes crop loss by producing carcinogens, including aflatoxin B1. This lepidopteran-fungus association is the most economically serious pest complex in Central Valley orchards, and evidence indicates that this relationship is mutualistic. We assessed preference and performance of navel orangeworm larvae associated with A. flavus in behavioral bioassays in which neonates were allowed to orient within arenas to media with or without fungal tissue, and performance bioassays in which larvae were reared with and without A. flavus on potato dextrose agar (PDA) and a semidefined almond PDA diet to evaluate effects on development and pupal weight. Navel orangeworm larvae were attracted to A. flavus and developed faster in its presence, indicating a nutritional benefit to the caterpillars. Larvae reached pupation ∼33% faster on diet containing A. flavus, and pupal weights were ∼18% higher for males and ∼13% higher for females on this diet. Our findings indicate that A. flavus plays an important role in larval orientation and development on infected hosts. The preference-performance relationship between navel orangeworms and Aspergillus flavus is consistent with a facultative mutualism that has broad implications for pest management efforts and basic understanding of Lepidoptera-plant interactions.
Collapse
Affiliation(s)
- Eline A Ampt
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (; ; )
| | - Daniel S Bush
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (; ; ),
| | - Joel P Siegel
- USDA-ARS, San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648
| | - May R Berenbaum
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (; ; )
| |
Collapse
|
11
|
Bagchi VA, Siegel JP, Demkovich MR, Zehr LN, Berenbaum MR. Impact of Pesticide Resistance on Toxicity and Tolerance of Hostplant Phytochemicals in Amyelois Transitella (Lepidoptera: Pyralidae). J Insect Sci 2016; 16:iew063. [PMID: 27620560 PMCID: PMC5019020 DOI: 10.1093/jisesa/iew063] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 06/24/2016] [Indexed: 05/08/2023]
Abstract
For some polyphagous insects, adaptation to phytochemically novel plants can enhance resistance to certain pesticides, but whether pesticide resistance expands tolerance to phytochemicals has not been examined. Amyelois transitella Walker (navel orangeworm) is an important polyphagous pest of nut and fruit tree crops in California. Bifenthrin resistance, partially attributable to enhanced cytochrome P450 (P450)-mediated detoxification, has been reported in an almond-infesting population exposed to intense pesticide selection. We compared the toxicity of bifenthrin and three phytochemicals-chlorogenic acid, and the furanocoumarins xanthotoxin and bergapten-to three strains of A. transitella: pyrethroid-resistant R347 (maintained in the laboratory for ∼10 generations), fig-derived FIG (in the laboratory for ∼25 generations), and CPQ-a laboratory strain derived from almonds ∼40 years ago). Whereas both Ficus carica (fig) and Prunus dulcis (almond) contain chlorogenic acid, furanocoumarins occur only in figs. Both R347 and FIG exhibited 2-fold greater resistance to the three phytochemicals compared with CPQ; surprisingly, bifenthrin resistance was highest in FIG. Piperonyl butoxide, a P450 synergist, increased toxicity of all three phytochemicals only in CPQ, implicating alternate tolerance mechanisms in R347 and FIG. To test the ability of the strains to utilize novel hostplants directly, we compared survival on diets containing seeds of Wisteria sinensis and Prosopis pallida, two non-host Fabaceae species; survival of FIG was highest and survival of R347 was lowest. Our results suggest that, while P450-mediated pesticide resistance enhances tolerance of certain phytochemicals in this species, it is only one of multiple biochemical adaptations associated with acquiring novel hostplants.
Collapse
Affiliation(s)
- Vikram A Bagchi
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Joel P Siegel
- USDA-ARS, San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648, USA
| | - Mark R Demkovich
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Luke N Zehr
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - May R Berenbaum
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| |
Collapse
|
12
|
Demkovich M, Dana CE, Siegel JP, Berenbaum MR. Effect of Piperonyl Butoxide on the Toxicity of Four Classes of Insecticides to Navel Orangeworm (Amyelois transitella) (Lepidoptera: Pyralidae). J Econ Entomol 2015; 108:2753-2760. [PMID: 26470383 DOI: 10.1093/jee/tov237] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 07/17/2015] [Indexed: 06/05/2023]
Abstract
Amyelois transitella (Walker) (Lepidoptera: Pyralidae), the navel orangeworm, is a highly polyphagous economic pest of almond, pistachio, and walnut crops in California. Increasing demand for these crops and their rising economic value has resulted in substantial increases of insecticide applications to reduce damage to acceptable levels. The effects of piperonyl butoxide (PBO), a methylenedioxyphenyl compound that can act as a synergist by inhibiting cytochrome P450-mediated detoxification on insecticide metabolism by A. transitella, were examined in a series of feeding bioassays with first-instar A. transitella larvae from a laboratory strain. PBO, however, can have a variety of effects on metabolism, including inhibition of glutathione-S-transferases and esterases and induction of P450s. In our study, PBO synergized the toxicity of acetamiprid, λ-cyhalothrin, and spinosad, suggesting possible involvement of P450s in their detoxification. In contrast, PBO interacted antagonistically with the organophosphate insecticide chlorpyrifos, reducing its toxicity, an effect consistent with inhibition of P450-mediated bioactivation of this pesticide. The toxicity of the anthranilic diamide insecticide chlorantraniliprole was not altered by PBO, suggestive of little or no involvement of P450-mediated metabolism in its detoxification. Because a population of navel orangeworm in Kern County, CA, has already acquired resistance to the pyrethroid insecticide bifenthrin through enhanced P450 activity, determining the effect of adding a synergist such as PBO on detoxification of all insecticide classes registered for use in navel orangeworm management can help to develop rotation practices that may delay resistance acquisition or to implement alternative management practices where resistance is likely to evolve.
Collapse
Affiliation(s)
- Mark Demkovich
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801.
| | - Catherine E Dana
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801
| | - Joel P Siegel
- USDA-ARS, San Joaquin Valley Agricultural Sciences Center, Parlier, CA, 93648
| | - May R Berenbaum
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801
| |
Collapse
|
13
|
Demkovich M, Siegel JP, Higbee BS, Berenbaum MR. Mechanism of Resistance Acquisition and Potential Associated Fitness Costs in Amyelois transitella (Lepidoptera: Pyralidae) Exposed to Pyrethroid Insecticides. Environ Entomol 2015; 44:855-863. [PMID: 26313992 DOI: 10.1093/ee/nvv047] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 03/23/2015] [Indexed: 06/04/2023]
Abstract
The polyphagous navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), is the most destructive pest of nut crops, including almonds and pistachios, in California orchards. Management of this insect has typically been a combination of cultural controls and insecticide use, with the latter increasing substantially along with the value of these commodities. Possibly associated with increased insecticide use, resistance has been observed recently in navel orangeworm populations in Kern County, California. In studies characterizing a putatively pyrethroid-resistant strain (R347) of navel orangeworm, susceptibility to bifenthrin and β-cyfluthrin was compared with that of an established colony of susceptible navel orangeworm. Administration of piperonyl butoxide and S,S,S-tributyl phosphorotrithioate in first-instar feeding bioassays with the pyrethroids bifenthrin and β-cyfluthrin produced synergistic effects and demonstrated that cytochrome P450 monooxygenases and carboxylesterases contribute to resistance in this population. Resistance is therefore primarily metabolic and likely the result of overexpression of specific cytochrome P450 monooxygenases and carboxylesterase genes. Resistance was assessed by median lethal concentration (LC50) assays and maintained across nine generations in the laboratory. Life history trait comparisons between the resistant strain and susceptible strain revealed significantly lower pupal weights in resistant individuals reared on the same wheat bran-based artificial diet across six generations. Time to second instar was greater in the resistant strain than the susceptible strain, although overall development time was not significantly different between strains. Resistance was heritable and may have an associated fitness cost, which could influence the dispersal and expansion of resistant populations in nut-growing areas in California.
Collapse
Affiliation(s)
- Mark Demkovich
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801.
| | - Joel P Siegel
- USDA-ARS, San Joaquin Valley Agricultural Sciences Center, Parlier, CA, 93648
| | - Bradley S Higbee
- Paramount Farming Company, 6801 E. Lerdo Highway, Shafter, CA, 93263
| | - May R Berenbaum
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801
| |
Collapse
|
14
|
Kuenen LPS, Siegel JP. Measure your septa release ratios: pheromone release ratio variability affected by rubber septa and solvent. J Chem Ecol 2015; 41:303-10. [PMID: 25801328 DOI: 10.1007/s10886-015-0557-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 01/04/2015] [Accepted: 03/03/2015] [Indexed: 11/25/2022]
Abstract
The type of solvent and the volume used to load pheromone components onto rubber septa had significant effects on pheromone release ratios, the variability of those release ratios, and the recoverability of the volatile components during subsequent extraction with hexane. Volatile release ratios of synthetic Oriental fruit moth (OFM) pheromone and additional volatile compounds were determined using a gas chromatograph column as a volatile trap for rapid (≤1 hr) analysis from individual rubber septa. Volatile compound solutions were prepared in hexane, pentane, CH2Cl2, and methyl tert-butyl ether, and a 10, 33, or 100 μl aliquot of each solution was applied to rubber septa. Septa loaded with 100 μl of CH2Cl2 emitted significantly (P < 0.05) higher alcohol: acetate (OH:Ac) ratios than septa loaded with the other solvents, which were all similar. Release ratios of the alcohol and acetate components of the OFM pheromone components were assessed over a 3 week period using septa loaded with each solvent. Regardless of loading solvent, the OFM OH:Ac ratios declined logarithmically over 3 weeks; however, the decay slope from septa loaded with CH2Cl2 solutions was different from those of the other three solvents, which were nearly all the same. A high variability in OH:Ac release ratios was measured overall, regardless of the solvent used or the volume it was applied in. Four compounds of near-equal mass: 1-dodecanol, 1-dodecanal, methyl decanoate, and tridecane emitted different release ratios dependent on the solvent, hexane or CH2Cl2, with which a septum was loaded. The more polar and the greater the mass of the test compound, the slower it was emitted from a septum regardless of solvent. These combined results plus comparisons to earlier reports, suggest that researchers should empirically assess the release ratios from septa to be used in bioassays rather than just reporting the type of septum, ratios of compounds applied and solvent used to prepare them.
Collapse
Affiliation(s)
- L P S Kuenen
- USDA, Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, 9611 South Riverbend Avenue, Parlier, CA, 93648-9757, USA,
| | | |
Collapse
|
15
|
Little RJ, Cohen ML, Dickersin K, Emerson SS, Farrar JT, Neaton JD, Shih W, Siegel JP, Stern H. The design and conduct of clinical trials to limit missing data. Stat Med 2012; 31:3433-43. [PMID: 22829439 PMCID: PMC5944851 DOI: 10.1002/sim.5519] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 05/25/2012] [Accepted: 06/14/2012] [Indexed: 11/06/2022]
Abstract
This article summarizes recommendations on the design and conduct of clinical trials of a National Research Council study on missing data in clinical trials. Key findings of the study are that (a) substantial missing data is a serious problem that undermines the scientific credibility of causal conclusions from clinical trials; (b) the assumption that analysis methods can compensate for substantial missing data is not justified; hence (c) clinical trial design, including the choice of key causal estimands, the target population, and the length of the study, should include limiting missing data as one of its goals; (d) missing-data procedures should be discussed explicitly in the clinical trial protocol; (e) clinical trial conduct should take steps to limit the extent of missing data; (f) there is no universal method for handling missing data in the analysis of clinical trials - methods should be justified on the plausibility of the underlying scientific assumptions; and (g) when alternative assumptions are plausible, sensitivity analysis should be conducted to assess robustness of findings to these alternatives. This article focuses on the panel's recommendations on the design and conduct of clinical trials to limit missing data. A companion paper addresses the panel's findings on analysis methods.
Collapse
Affiliation(s)
- R J Little
- Department of Biostatistics, University of Michigan, Ann Arbor, MI 48109, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Higbee BS, Siegel JP. Field efficacy and application timing of methoxyfenozide, a reduced-risk treatment for control of navel orangeworm (Lepidoptera: Pyralidae) in almond. J Econ Entomol 2012; 105:1702-1711. [PMID: 23156167 DOI: 10.1603/ec11389] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Large-scale field efficacy trials of methoxyfenozide (Intrepid), a reduced-risk molting agonist insecticide, were conducted in 2004 and 2005 in an orchard containing 'Nonpareil' and 'Sonora almonds [Prunus dulcis (Mill.) D.A. Webb] located in Kern County, CA. Methoxyfenozide applied one to three times, the organophosphate phosmet (Imidan) alone or in combination with methoxyfenozide, or the pyrethroid permethrin (Perm-Up) were tested for efficacy against the primary lepidopteran pest navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), and three other lepidopteran pests of almond: oriental fruit moth, Grapholita molesta (Busck); oblique-banded leafroller, Choristoneura rosaceana (Harris); and peach twig borer, Anarsia lineatella Zeller. Two or three applications of methoxyfenozide (bracketing hull split or spring plus bracketing hull split) were more effective than a single hull split application of phosmet, phosmet combined with permethrin, or methoxyfenozide. In these trials, a spring application followed by a posthull split application was as effective as the applications bracketing hull split. Navel orangeworm accounted for > 60% of the total damage, whereas oriental fruit moth and peach twig borer were the dominant secondary pests. In experiments conducted in 2010 to assess the direct toxicity of methoxyfenozide to navel orangeworm eggs under field conditions, exposure to methoxyfenozide reduced survival by 96-99%. We conclude that this reduced-risk insecticide is effective, although its efficacy is maximized with more than one well-timed application.
Collapse
Affiliation(s)
- Bradley S Higbee
- Paramount Farming Company, 33141 E Lerdo Highway, Bakersfield, CA 93308, USA.
| | | |
Collapse
|
17
|
Niu G, Pollock HS, Lawrance A, Siegel JP, Berenbaum MR. Effects of a naturally occurring and a synthetic synergist on toxicity of three insecticides and a phytochemical to navel orangeworm (Lepidoptera: Pyralidae). J Econ Entomol 2012; 105:410-417. [PMID: 22606811 DOI: 10.1603/ec10194] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), is the most destructive lepidopteran pest of almonds [Prunus dulcis (Mill.) D.A.Webb] and pistachios (Pistacia vera L.) in California and is a serious problem in figs (Ficus carica L.) and walnuts (Juglans spp.). In addition to direct damage, larval feeding leaves nuts vulnerable to infection by Aspergillus spp., fungi that produce toxic aflatoxins. A potentially safe and sustainable approach for managing navel orangeworm in orchards may be to use natural essential oil synergists to interfere with this insect's ability to detoxify insecticides and phytochemicals. We tested the effects of a naturally occurring plant-derived chemical, myristicin, and a synthetic inhibitor of cytochrome P450 monooxygenases (P450s), piperonyl butoxide, on the toxicity of three insecticides (alpha-cypermethrin, tau-fluvalinate, and methoxyfenozide [Intrepid]) and a phytochemical (xanthotoxin) to A. transitella. Piperonyl butoxide significantly synergized alpha-cypermethrin and tau-fluvalinate, whereas myristicin synergized only alpha-cypermethrin. Piperonyl butoxide synergized the toxicity of xanthotoxin as early as 72 h after exposure, whereas myristicin synergized xanthotoxin after 120 h. In view of these findings and the limited availability of environmentally safe synthetic insecticides for sustainable management, particularly in organic orchards, myristicin is a potential field treatment in combination with insecticides to reduce both navel orangeworm survival and aflatoxin contamination of nuts. In addition, this study demonstrates that in A. transitella the insect growth regulator methoxyfenozide is not detoxified by P450s.
Collapse
Affiliation(s)
- Guodong Niu
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | | | | | | | | |
Collapse
|
18
|
Burks CS, Higbee BS, Siegel JP, Brandl DG. Comparison of trapping for eggs, females, and males of the naval orangeworm (Lepidoptera: Pyralidae) in almonds. Environ Entomol 2011; 40:706-713. [PMID: 22251650 DOI: 10.1603/en10253] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The navel orangeworm is the primary insect pest of almonds in California, and egg traps are the primary means of monitoring this pest. A previous study found that the current use of 2-4 traps per 64 ha block usually is not sufficient to provide management information specifically for that block. In this study, we compare data from large grids of egg traps in varied commercial almond orchards with trapping data for females and males, with the objective of finding a more cost-effective monitoring program using currently available attractants. The proportion of egg traps with eggs was highly correlated with mean eggs per egg trap, and with females and males trapped simultaneously at the same location. Almond variety and the type of bait used had little impact on the relationship between the proportion of egg traps with eggs and the number of eggs per traps. Traps in orchards with more unharvested (mummy) almonds had more eggs, suggesting that navel orangeworm abundance affected traps more than competition from mummies. Laboratory experiments comparing age-specific oviposition in two-choice and no-choice situations found that younger, more fecund females laid a greater proportion of eggs on the preferred substrate in a two-choice situation, but that age-specific fecundity was not different between substrates in no-choice tests. These findings indicate that the proportion of egg traps with eggs provides a more stable indication of navel orangeworm phenology than mean eggs per trap. We suggest that similar information could be obtained in a more cost-effective manner with female trapping.
Collapse
Affiliation(s)
- Charles S Burks
- United States Department of Agriculture-Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648, USA.
| | | | | | | |
Collapse
|
19
|
Siegel JP, Bas Kuenen LPS. Variable developmental rate and survival of navel orangeworm (Lepidoptera: Pyralidae) on pistachio. J Econ Entomol 2011; 104:532-539. [PMID: 21510201 DOI: 10.1603/ec10177] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A series of laboratory and field studies were conducted using two lines of navel orangeworm, reared on different stages of new crop and mummy pistachios, Pistacia vera L. This study demonstrated the potential importance of malformed pistachios (pea splits) to the population dynamics of navel orangeworm, because these nuts, which are available as early as two months before mature nuts, supported navel orangeworm development and survival. Overall, the developmental rate on new crop pistachios is fastest on mature nuts, 422.3 +/- 123 degree-days (DD, degrees C), but other factors such as exposure to insecticide residue also sped development, although survival decreased. Development took the longest on unharvested nuts (mummies) dried at 90 degrees C for 24 h, 2664.7 +/- 131.4 DD. In most trials development was variable and two generations could develop at the fastest rate before the slowest individual completed development, which in turn calls into question the concept of discrete generations. Generally, survival was highest on mature pistachios and other stages of new crop nut and lowest on mummies collected in May. Survival was also higher on the new varieties 'Lost Hills' and 'Golden Hills' (24.7 and 32.0%, respectively) than on the most extensively planted variety 'Kerman' (13.3%). In our trials, both the rate of development and survival were dependent on nut stage, age, variety, and quality, indicating that pistachios, like almonds, Prunus dulcis (Mill.) D. A. Webb, are a dynamic rather than a static nutrient source for navel orangeworm.
Collapse
Affiliation(s)
- Joel P Siegel
- USDA-ARS, San Joaquin Valley Agricultural Sciences Center, Commodity Protection and Quality Unit, Parlier, CA 93648, USA.
| | | |
Collapse
|
20
|
Niu G, Rupasinghe SG, Zangerl AR, Siegel JP, Schuler MA, Berenbaum MR. A substrate-specific cytochrome P450 monooxygenase, CYP6AB11, from the polyphagous navel orangeworm (Amyelois transitella). Insect Biochem Mol Biol 2011; 41:244-253. [PMID: 21220011 DOI: 10.1016/j.ibmb.2010.12.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Revised: 12/30/2010] [Accepted: 12/31/2010] [Indexed: 05/30/2023]
Abstract
The navel orangeworm Amyelois transitella (Walker) (Lepidoptera: Pyralidae) is a serious pest of many tree crops in California orchards, including almonds, pistachios, walnuts and figs. To understand the molecular mechanisms underlying detoxification of phytochemicals, insecticides and mycotoxins by this species, full-length CYP6AB11 cDNA was isolated from larval midguts using RACE PCR. Phylogenetic analysis of this insect cytochrome P450 monooxygenase established its evolutionary relationship to a P450 that selectively metabolizes imperatorin (a linear furanocoumarin) and myristicin (a natural methylenedioxyphenyl compound) in another lepidopteran species. Metabolic assays conducted with baculovirus-expressed P450 protein, P450 reductase and cytochrome b(5) on 16 compounds, including phytochemicals, mycotoxins, and synthetic pesticides, indicated that CYP6AB11 efficiently metabolizes imperatorin (0.88 pmol/min/pmol P450) and slowly metabolizes piperonyl butoxide (0.11 pmol/min/pmol P450). LC-MS analysis indicated that the imperatorin metabolite is an epoxide generated by oxidation of the double bond in its extended isoprenyl side chain. Predictive structures for CYP6AB11 suggested that its catalytic site contains a doughnut-like constriction over the heme that excludes aromatic rings on substrates and allows only their extended side chains to access the catalytic site. CYP6AB11 can also metabolize the principal insecticide synergist piperonyl butoxide (PBO), a synthetic methylenedioxyphenyl compound, albeit slowly, which raises the possibility that resistance may evolve in this species after exposure to synergists under field conditions.
Collapse
Affiliation(s)
- Guodong Niu
- Department of Entomology, University of Illinois, Urbana, IL 61801, USA
| | | | | | | | | | | |
Collapse
|
21
|
Kuenen LPS, Siegel JP. Protracted emergence of overwintering Amyelois transitella (Lepidoptera: Pyralidae) from pistachios and almonds in California. Environ Entomol 2010; 39:1059-1067. [PMID: 22127156 DOI: 10.1603/en09277] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The navel orangeworm, Amyelois transitella (Walker), is the primary insect pest of pistachios and almonds in California. Four years of research (2002-2006) were conducted in Madera and Kern Counties to elucidate the pattern of adult emergence of the overwintering navel orangeworm population. Springtime emergence from unharvested (mummy) nuts was protracted (600 degree-days or more from 1 January of each year) and in 2004 and 2006 extended to mid-July. The population structure, sex ratio, and timing of emergence differed between pistachio and almond mummies. Pistachio populations had a significantly greater proportion of late stage individuals compared with almond mummies, 85.7 versus 34.1%. The sex ratio of adults emerging from pistachio mummies was significantly skewed with a ratio 57:43 male:female compared with 50:50 in almond mummies. Emergence from mummies held outdoors (variable temperature) began in early March and continued through early June in both pistachio mummies and almond mummies. The adult emergence pattern from pistachio mummies contained a single emergence peak, whereas emergence from almond mummies occurred in multiple peaks. These same patterns occurred when mummies were held at constant temperature, and the emergence peak from pistachio mummies occurred sooner. The impact of these findings on understanding navel orangeworm population dynamics and current control recommendations is discussed.
Collapse
Affiliation(s)
- L P S Kuenen
- United States Department of Agriculture-Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, 9611 South Riverbend Avenue, Parlier, CA 93648, USA.
| | | |
Collapse
|
22
|
Siegel JP, Kuenen LPSB, Ledbetter C. Variable development rate and survival of navel orangeworm (Lepidoptera: Pyralidae) on wheat bran diet and almonds. J Econ Entomol 2010; 103:1250-1257. [PMID: 20857734 DOI: 10.1603/ec09309] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A series of laboratory and field studies were conducted using three lines of navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), reared on wheat bran diet and almonds, Prunus dulcis (Mill.) D.A.Webb, at constant and fluctuating temperature. The duration of development on wheat bran diet at constant temperature differed significantly among the three lines. Development was as much as 40% faster at constant temperature than at fluctuating temperatures, consequently the developmental duration determined at constant temperature was not an absolute measure. When the maximum temperature in fluctuating regimes exceeded 43 degrees C, survival decreased by 50% compared with the constant temperature control. In almonds held at constant temperature, the developmental rate on new-crop nuts was variety-dependent and was fastest on 'Nonpareil' almonds and slowest on the experimental selection '23-122'. Development and survival were also variety-dependent on unharvested (mummy) almonds, and navel orangeworm average emergence was earliest from Nonpareil and latest from 'Carmel' nuts, differing by 529 degree-days, whereas survival was the highest on 'Butte', 35.7%, and the lowest on Carmel nuts, 7.2%. In our trials, both the speed of development and survival depended on host age, variety and quality, indicating that almonds were a dynamic rather than a static nutrient source for navel orangeworm. Identifying the factors responsible for variation in development and survival will give insight into improving control strategies.
Collapse
Affiliation(s)
- Joel P Siegel
- USDA-ARS, San Joaquin Valley Agricultural Sciences Center, Commodity Protection and Quality Unit, Parlier, CA 93648, USA.
| | | | | |
Collapse
|
23
|
Solter LF, Siegel JP, Pilarska DK, Higgs MC. The impact of mixed infection of three species of microsporidia isolated from the gypsy moth, Lymantria dispar L. (Lepidoptera: Lymantriidae). J Invertebr Pathol 2002; 81:103-13. [PMID: 12445794 DOI: 10.1016/s0022-2011(02)00155-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The outcome of mixed infection by three species of microsporidia in the genera Endoreticulatus, Nosema, and Vairimorpha, isolated from different populations of Lymantria dispar in Bulgaria, was evaluated in the laboratory. All possible combinations of two species were administered either simultaneously or sequentially to larvae, and mortality, duration of development, and larval weight at 20 days post-infection (simultaneous inoculation) or 23 days post-infection (sequential inoculation) were chosen as the outcome variables. Larvae were also dissected and the presence of each species of microsporidia and the tissues infected were recorded for each treatment. Effects of infection were dependent on both host sex and the type of exposure. Infected larvae were more likely to die than uninfected larvae, but there were no differences in mortality between single and mixed infections. Addition of Endoreticulatus to infections of Nosema or Vairimorpha significantly increased duration of development to the fourth ecdysis; this effect was additive. Addition of Nosema or Vairimorpha to an existing infection had no such effect. When Nosema was administered simultaneously with Endoreticulatus or Vairimorpha, infected larvae weighed more than larvae that had single infections with either pathogen. Nosema was displaced from the silk glands by Vairimorpha and Nosema suppressed octospore formation by Vairimorpha in fat body. The histological evidence combined with the data on larval weight supports the hypothesis that competition occurred in mixed infections.
Collapse
Affiliation(s)
- Leellen F Solter
- Illinois Natural History Survey, 140 NSRC, 1101 W. Peabody Dr., Urbana, IL 61801, USA.
| | | | | | | |
Collapse
|
24
|
Siegel JP, Lacey LA, Vossbrinck CR. Impact of a North American isolate of the microsporidium Nosema carpocapsae on a laboratory population of the codling moth, Cydia pomonella. J Invertebr Pathol 2001; 78:244-50. [PMID: 12009806 DOI: 10.1006/jipa.2001.5071] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nosema carpocapsae is a microsporidian pathogen of the codling moth, Cydia pomonella. We report the occurrence of this pathogen in a colony originating from collections made in the United States. This is the first record of N. carpocapsae infecting North American codling moths. This North American isolate of N. carpocapsae was indistinguishable from isolates received from New Zealand and Bulgaria, based on small subunit ribosomal RNA sequencing, but was more virulent than the previously described New Zealand isolate. In the laboratory, infected larvae and pupae had increased mortality compared to their uninfected counterparts and developmental time increased by 1 week. There was no effect on female fecundity. Within a cohort of eggs laid by infected females, neonates that emerged first were more likely to be uninfected. We established an uninfected colony by interrupting horizontal transmission and only utilizing the larvae that emerged from the first-laid eggs.
Collapse
Affiliation(s)
- J P Siegel
- USDA/ARS San Joaquin Valley Agricultural Sciences Center, 9611 South Riverbend Avenue, Parlier, California 93648, USA.
| | | | | |
Collapse
|
25
|
Siegel JP, Smith AR, Novak RJ. Recovery of commercially produced Bacillus thuringiensis var. israelensis and Bacillus sphaericus from tires and prevalence of bacilli in artificial and natural containers. J Am Mosq Control Assoc 2001; 17:33-41. [PMID: 11345416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We conducted surveys to identify the species of spore-forming bacteria present in natural and artificial containers. Most of our samples came from Illinois. Identification was based on the cellular fatty acid composition of the bacterial cell wall. In addition, we utilized a custom database for commercially produced strains of Bacillus thuringiensis var. israelensis (Bti) and B. sphaericus, to differentiate between larvicidal isolates with commercial or native origin. Native Bti was present at low levels in almost all habitats but was not recovered from bromeliads and metal containers. In temporary woodland pools, 27.9% of the colonies recovered were native Bti. We did not recover larvicidal B. sphaericus in untreated habitats. VectoBac and VectoLex were applied to tires containing water and the tires were sampled 3 months and 9 months after treatment. Isolates of Bti and B. sphaericus with commercial origin were recovered as long as 9 months after application. We noticed numerous cadavers of Aedes triseriatus in several tires 9 months after treatment with VectoBac. We could not determine if this mortality resulted from recycling of Bti in these tires or whether insecticidal crystal proteins from the original treatment were resuspended. Bacillus thuringiensis var. israelensis isolates with commercial ancestry were recovered from untreated tires 9 months after application. Isolates of larvicidal B. sphaericus that differed from the bacteria in VectoLex were also recovered from untreated tires.
Collapse
Affiliation(s)
- J P Siegel
- Illinois Natural History Survey, Campaign 61820, USA
| | | | | |
Collapse
|
26
|
Schwieterman WD, Weiss KD, Tiwari J, Siegel JP. Changes in trial parameters. Lancet 2001; 357:314. [PMID: 11214164 DOI: 10.1016/s0140-6736(05)71764-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
27
|
Abstract
The United States Environmental Protection Agency between the years 1961 and 1995 registered 177 products containing viable Bacillus thuringiensis (Bt). Numerous laboratory studies have demonstrated that Bt and Bt products are noninfectious and are toxic to mammals only at a dose > or =10(8) colony forming units (cfu) per mouse (a human equivalent based on the weight of >10(11) cfu). In contrast, as few as three vegetative cells of Bacillus anthracis can kill mice (a human equivalent of >10(3) cfu). There are only two literature reports of Bt infection in man between the year 1997 and the present, and all infected individuals had experienced either extensive burns or a blast injury, which predisposed them to infection. Two epidemiology studies conducted during large-scale aerial Bt serovar kurstaki spray campaigns reported no increased incidence of illness. Some recent papers have expressed concern about the production of Bacillus cereus enterotoxins by Bt isolates. Laboratory studies found no evidence of illness in rats and sheep fed Bt products, nor have epidemiology studies found increased incidence of diarrhea during Bt aerial spray campaigns. Increases in human antibody levels following exposure to Bt products have been reported but there was no increased incidence in asthma or other illness. Based on laboratory studies and field experience, Bt insecticides have an excellent safety record.
Collapse
Affiliation(s)
- J P Siegel
- USDA/ARS Horticultural Crops Research Center, 2021 South Peach Avenue, Fresno, California 93727, USA.
| |
Collapse
|
28
|
Fogelman I, Davey V, Ochs HD, Elashoff M, Feinberg MB, Mican J, Siegel JP, Sneller M, Lane HC. Evaluation of CD4+ T cell function In vivo in HIV-infected patients as measured by bacteriophage phiX174 immunization. J Infect Dis 2000; 182:435-41. [PMID: 10915073 DOI: 10.1086/315739] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/1999] [Revised: 04/17/2000] [Indexed: 11/03/2022] Open
Abstract
Bacteriophage phiX174 immunization was used to measure CD4(+) T cell function in vivo in human immunodeficiency virus (HIV)-infected patients across all disease stages. Function was evaluated by measuring the ability of T cells to provide help to B cells in antibody production, amplification, and isotype switching. A total of 33 patients and 10 controls received 3 bacteriophage phiX174 immunizations 6 weeks apart. The patients' responses regarding bacteriophage-specific total antibody titers and IgG titers were quantitatively and qualitatively inferior to the controls' responses. Overall, 7 of 33 patients had normal T cell function. Baseline CD4 counts provided the strongest correlation with total antibody and IgG titers. HIV RNA had a weaker association with responses but had some predictive power among patients with a CD4 count >200 cells/microL. Bacteriophage phiX174 immunization seems to be a useful tool for measuring immune function in vivo, which suggests that most HIV-infected patients may have abnormal CD4(+) T cell function despite adequate antiretroviral treatment.
Collapse
Affiliation(s)
- I Fogelman
- Biologic Consulting, Inc., Edgewater, MD 21037, USA. ilanafog@aol. com
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Affiliation(s)
- J P Siegel
- Center for Biologics Evaluation and Research, Food and Drug Administration, Rockville, MD 20852, USA.
| |
Collapse
|
30
|
Affiliation(s)
- J P Siegel
- USDA Agricultural Research Service, Horticultural Crops Research Laboratory, Fresno, California 93727, USA
| | | | | |
Collapse
|
31
|
Siegel JP, Novak RJ. Duration of activity of the microbial larvicide VectoLex CG (Bacillus sphaericus) in Illinois catch basins and waste tires. J Am Mosq Control Assoc 1999; 15:366-370. [PMID: 10480129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The duration of activity of a formulation of Bacillus sphaericus, VectoLex CG, for control of Culex species was evaluated in 338 catch basins in Urbana, IL, and compared to Altosid in 346 catch basins in Champaign, IL. The activity of VectoLex in car and truck waste tires was evaluated in a tire dump located in Pembroke Township, IL. In catch basins, 1 g of VectoLex per catch basin gave the same control as one Altosid briquet. Both larvicides were effective against Culex sp. in catch basins for 1 month, and the duration of control with VectoLex lasted 44 days in one catch basin. VectoLex was considerably cheaper to apply than Altosid briquets, at 0.64 cents per catch basin compared to 90.75 cents, respectively. However, the Altosid briquets were judged to be easier to apply from a vehicle than VectoLex granules. VectoLex (22.6 kg) was used to treat approximately 6,000 car and truck tires; some of the tires were in direct sunlight whereas others were shaded. Aedes triseriatus was the dominant species in these tires. Tires treated with VectoLex contained significantly fewer mosquitoes than control tires, and even 65 days after application, control tires were 16.7 times more likely to contain larvae. We conclude that VectoLex was effective when used in Illinois catch basins and tire dumps, and emphasize that it is more appropriate to base tire treatment rates on the total number of tires present than on a kilogram per hectare basis.
Collapse
Affiliation(s)
- J P Siegel
- Illinois Natural History Survey, Center for Economic Entomology, Champaign, IL 61820, USA
| | | |
Collapse
|
32
|
Karakowsky L, Siegel JP. The effects of proportional representation and gender orientation of the task on emergent leadership behavior in mixed-gender work groups. J Appl Psychol 1999; 84:620-31. [PMID: 10504894 DOI: 10.1037/0021-9010.84.4.620] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Much of the research that has examined the behavioral consequences of membership in mixed-gender work groups suggests that men are more participative and influential in task-related behavior. Drawing from elements of sociological, structural, and psychological perspectives, this study examined the effects of group gender composition and gender orientation of the group's task on patterns of emergent leadership behavior. Participants were assigned to male-dominated, female-dominated, or balanced-gender groups for the purpose of discussing and generating solutions for two business-related cases--each case emphasized either male-oriented or female-oriented expertise. The findings suggest that the proportional representation of men and women in a work group, along with the gender orientation of the group's task, can significantly influence the level of leadership behavior exhibited in group activity.
Collapse
Affiliation(s)
- L Karakowsky
- Department of Administrative Studies, York University, Toronto, Ontario, Canada.
| | | |
Collapse
|
33
|
Mehrotra PT, Donnelly RP, Wong S, Kanegane H, Geremew A, Mostowski HS, Furuke K, Siegel JP, Bloom ET. Production of IL-10 by human natural killer cells stimulated with IL-2 and/or IL-12. J Immunol 1998; 160:2637-44. [PMID: 9510161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Human NK cell activity can be augmented in vitro by stimulation with IL-2 or IL-12, both of which also induce the production of IFN-gamma, TNF-alpha, and granulocyte-macrophage CSF by NK cells. For the first time, we demonstrate that freshly purified NK cells stimulated with IL-2 proliferated and produced IL-10 in a dose-dependent manner. IL-10 mRNA expression, as detected by semiquantitative reverse transcription-PCR, reached peak levels at 24 h. IL-10 protein was detectable on day 2 and further increased on days 3 and 6 as measured by ELISA. However, IL-12 alone induced neither substantial proliferation nor detectable IL-10 production by fresh NK cells, but it synergized with IL-2 in inducing IL-10 mRNA expression and protein synthesis. IL-10 production by activated NK cells was confirmed by intracytoplasmic cytokine staining by three-color immunofluorescence of CD16+ and/or CD56+ NK cells with anti-IL-10 antibody. IL-10 production by NK cells was further confirmed in the NK-like cell line, YT, which constitutively expressed IL-10 mRNA and protein. IL-12 alone did not induce NK proliferation, but it inhibited IL-2-induced proliferation. Neutralization of endogenously produced IL-10 with anti-IL-10 antibodies did not overcome the inhibition of IL-2-induced proliferation by IL-12. Together, these results demonstrate that IL-2 and IL-12 synergize to induce IL-10 production by human NK cells and that IL-12 inhibits IL-2 induced NK cell proliferation by an IL-10-independent mechanism.
Collapse
Affiliation(s)
- P T Mehrotra
- Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Rockville, MD 20852-1448, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Siegel JP, Novak RJ. Field trials of VectoLex CG, a Bacillus sphaericus larvicide, in Illinois waste tires and catch basins. J Am Mosq Control Assoc 1997; 13:305-310. [PMID: 9474554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The susceptibilities of Aedes triseriatus (Say), Anopheles punctipennis (Say), Culex restuans (Theobald), and Culex pipiens (L.) larvae to VectoLex CG were determined. VectoLex, formulated on corncob granules (10-14 mesh) was applied to 2 tire dumps and numerous catch basins located in east-central Illinois. VectoLex, formulated as effervescent tablets, was also applied to catch basins. In a sunlit dump, there was a 99.6% reduction in Ae. triseriatus, Cx. restuans, and Cx. pipiens larvae as long as 32 days after treatment, and no pupae were recovered during this interval. There was still a 71.6% larval reduction 74 days after treatment. There was an overall reduction of 22% for An. punctipennis larvae. In a shaded dump, no larval Ae. triseriatus, Cx. restuans, or Cx. pipiens were recovered for 25 days after treatment, and no pupae were recovered 25-67 days after treatment. There was still a 68.7% larval reduction 74 days after treatment. An. punctipennis was unaffected. In one catch basin study, VectoLex was comparable to Altosid (average of 46 days vs. 50 days until larvae were recovered from catch basins). As the summer progressed, the duration of VectoLex control was reduced to 30 days. VectoLex effervescent tablets (evaluated mid-August through September) gave 18-day control. VectoLex was effective against Ae. triseriatus, Cx. restuans, and Cx. pipiens, but was not effective against An. punctipennis in waste tires. VectoLex was effective against Cx. restuans and Cx. pipiens in catch basins.
Collapse
Affiliation(s)
- J P Siegel
- Illinois Natural History Survey, Center for Economic Entomology, Champaign 61820, USA
| | | |
Collapse
|
35
|
Siegel JP. Stereotactic needle core biopsy. Am J Surg 1997; 173:453-4. [PMID: 9168088 DOI: 10.1016/s0002-9610(97)89583-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
36
|
Siegel JP, Smith AR, Novak RJ. Comparison of the cellular fatty acid composition of a bacterium isolated from a human and alleged to be Bacillus sphaericus with that of Bacillus sphaericus isolated from a mosquito larvicide. Appl Environ Microbiol 1997; 63:1006-10. [PMID: 9055417 PMCID: PMC168392 DOI: 10.1128/aem.63.3.1006-1010.1997] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The cellular fatty acid (CFA) composition of the cytoplasmic membrane of a bacillus isolated from a human lung and deposited in the National Collection of Type Cultures as Bacillus sphaericus NCTC 11025 was determined by gas-liquid chromatography. The CFA composition of B. sphaericus 2362, isolated from a microbial larvicide, and those of B. sphaericus reference strains obtained from public collections were also determined. Samples were grouped by hierarchical cluster analysis based on the unpaired-group method using arithmetic averages. Samples that linked at a Euclidean distance of < or = 2.0 U were considered to belong to the same strain. NCTC 11025 and the type strain of B. sphaericus, ATCC 14577, were mixed; all other isolates were monotypic. The predominant fatty acid in NCTC 11025 was 12-methyltetradecanoic acid, while the predominant fatty acid in the remaining isolates was 13-methyltetradecanoic acid. NCTC 11025 linked to the other isolates at a Euclidean distance of 83.8 U, and we concluded that it belongs to a different species that we could not identify. We could distinguish among six DNA homology groups of B. sphaericus by using fatty acids. Within DNA homology group IIA, strain 2362 could be distinguished from other strains belonging to serotype H5a, 5b. We concluded that CFA analysis is a useful technique to determine if future human isolates identified as B. sphaericus in fact belong to other species of bacteria or whether the isolates originated from commercial products.
Collapse
Affiliation(s)
- J P Siegel
- Illinois Natural History Survey, Center for Economic Entomology, Champaign, Illinois 61820, USA.
| | | | | |
Collapse
|
37
|
|
38
|
Siegel JP, Cieslik R, Thennisch J, Clarke L, Novak RJ. Dispersal of 10-14-mesh corncob granules in stacked tires. J Am Mosq Control Assoc 1996; 12:325-328. [PMID: 8827614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Dispersal of 10-14-mesh corncob granules was evaluated in 2 random-stacked tire piles, one shingle-stacked tire pile, and one column-stacked tire pile located in a used-tire storage facility in Chicago, IL. Ninety percent and 98%, respectively, of the tires in the 2 random-stacked piles contained granules. In the shingle-stacked tire pile 87% of the tires sampled contained granules, and the number of granules per tire was dependent on depth. The 2 bottom rows of tires were 73.9% less likely to contain granules than the 5 rows above them. In the column-stacked tire pile 91.2% of the tires contained granules and the relationship between granule recovery and tire depth was logarithmic. Overall, the dispersal of 10-14-mesh corncob granules was comparable to that of 8-mesh corncob granules evaluated in a previous study at this site.
Collapse
Affiliation(s)
- J P Siegel
- Illinois Natural History Survey, Center for Economic Entomology, Champaign 61820, USA
| | | | | | | | | |
Collapse
|
39
|
Abstract
To elucidate mechanisms by which human CD4+ cells mediated cytolytic activity, we studied the expression of cytolytic proteins and the effects of inhibitors and mAbs on T-cell clones. Of seven cytolytic CD4+ clones, three were specific for the HLA-DR17, while four recognized DR18. Anti-HLA-DR mAb and anti-CD4 mAb blocked lysis. In addition, N alpha-p-tosyl-L-lysine chloromethylketone (TLCK), a serine esterase inhibitor, as well as cytochalasin B and monensin, antagonists of secretory pathways, inhibited CD4+ CTLs, whereas the absence of extracellular Ca+2 or the presence of Ca+2 channel blockers partially inhibited cytotoxicity. CD4+ CTLs induced apoptosis of target cell nuclei and membrane damage simultaneously. The CD4+ clones synthesized perforin and granzyme B and expressed the granule-associated protein TIA-1. Our studies indicate that two distinct mechanisms may contribute to cytolysis by CD4+ clones: (1) a Ca+2-dependent mechanism associated with the cytotoxic granules and (2) a Ca+2-insensitive mechanism.
Collapse
Affiliation(s)
- B Susskind
- Department of Surgery, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | | | | | | | | | | | | |
Collapse
|
40
|
Nawrocki SJ, Randle YH, Vodkin MH, Siegel JP, Novak RJ. Evaluation of a reverse transcriptase-polymerase chain reaction assay for detecting St. Louis encephalitis virus using field-collected mosquitoes (Diptera: Culicidae). J Med Entomol 1996; 33:123-127. [PMID: 8906915 DOI: 10.1093/jmedent/33.1.123] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A reverse transcriptase-polymerase chain reaction assay (RT-PCR) was compared with a tissue culture assay (TC) and an enzyme immunoassay (EIA) to detect St. Louis encephalitis virus (SLEV) in mosquito pools. Overall, 1,725 mosquito pools with a low viral prevalence (3.3%-5.0%) were tested. The comparison of the EIA to TC showed that the EIA was 0.947 sensitive, 0.988 specific, and 0.987 accurate. Comparison of RT-PCR to TC showed that the RT-PCR was 0.947 sensitive, 0.980 specific, and 0.979 accurate. Comparison of the RT-PCR to EIA showed that the RT-PCR was 0.878 sensitive, 0.987 specific, and 0.982 accurate. Because of speed, accuracy, and cost, either the RT-PCR or the EIA is recommended as the primary screen. RT-PCR has an advantage over EIA, because the amplified product contains sequence information which can confirm its identity. TC, EIA, or both can be applied as a 2nd assay for the confirmation of samples suspected as positives by the RT-PCR.
Collapse
Affiliation(s)
- S J Nawrocki
- Harris County Mosquito Control District, Houston, TX 77054, USA
| | | | | | | | | |
Collapse
|
41
|
Siegel JP, Smith AR, Novak RJ. Cellular fatty acid analysis of Bacillus thuringiensis ssp. israelensis (ONR-60A). J Am Mosq Control Assoc 1995; 11:176-185. [PMID: 7595442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The cellular fatty acid composition of Bacillus thuringiensis ssp. israelensis (B.t.i.) ONR-60A was determined by gas-liquid chromatography (GLC). Isolates of ONR-60A were obtained from the Bacillus Genetic Stock Center, Pasteur Institute, and USDA culture collections. These isolates were compared to one another and the culture collections differed in the strains that they contained. Eleven separate strains of ONR-60A were identified, based on fatty acid composition of the cell envelope. The current Pasteur Institute international standard for B.t.i., IPS 82, was also analyzed and it consisted of 3 strains using these same criteria. Profiles were created for each strain found in ONR-60A and IPS 82, and validated against profiles of commercially produced B.t.i. from 2 time periods, 1983-84, and 1990-94. Approximately 84% of the commercially produced B.t.i. (134 out of 160 agar plates) was identified as belonging to the strains found in ONR-60A and in IPS 82. The most prevalent strain found in IPS 82 is also the most prevalent strain in the recently produced commercial material, 40.8% of the commercial plates analyzed, but commercially produced B.t.i. also retained a strong ONR-60A ancestry (35% of the plates analyzed).
Collapse
Affiliation(s)
- J P Siegel
- Center for Economic Entomology, University of Illinois, Champaign 61820, USA
| | | | | |
Collapse
|
42
|
Mehrotra PT, Grant AJ, Siegel JP. Synergistic effects of IL-7 and IL-12 on human T cell activation. J Immunol 1995; 154:5093-102. [PMID: 7730615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We have previously demonstrated that human rIL-12 alone can augment the development of cytotoxic activity in stimulated CD8+ T cells. The present study was undertaken to examine the interactions of rIL-7 and rIL-12 on human peripheral blood T cell activation and CTL differentiation. Purified T lymphocytes were pulsed overnight with immobilized alpha-CD3 and then cultured for 3 additional days with IL-7 and/or IL-12. The combination of IL-7 and IL-12 synergistically enhanced the proliferation of either fresh CD3+ T cells or an IL-2-dependent CD4+ T cell line, Kit-225-K6. This synergy was seen on both subsets of T cells; however, CD8+ T cells were usually more responsive to IL-7 and IL-12 at lower concentrations than were CD4+ T cells. Furthermore, these cytokines additively/synergistically augmented the cytotoxic activity of CD8+ T cells. Abs to IL-2 and IL-2R alpha blocked the synergistic effect on proliferation of CD4+ T cells, but had a minimal effect on the synergistic response of the proliferative and cytotoxic activity of CD8+ T cells. Examination of the effects of IL-7 and IL-12 on the expression of IL-12 receptor on T cells revealed an increase in the subunit of IL-12R by IL-7 as determined by flow cytometric analysis. We analyzed the effects on IFN-gamma production by CD8+ T cells and found that IL-7 alone did not induce detectable levels of IFN-gamma production but together with IL-12 it synergistically enhanced the production of IFN-gamma. We also found that IFN-gamma was probably not required for enhanced CTL activity of CD8+ T cells, because Ab to human IFN-gamma did not block additive/synergistic effects of either cytokine. The synergistic stimulatory activity of IL-7 and IL-12 may be of significance in vivo and may provide an alternative mechanism of stimulating T cells for use in immunotherapy.
Collapse
Affiliation(s)
- P T Mehrotra
- Laboratory of Cellular Immunology, Food and Drug Administration, Rockville, MD 20852, USA
| | | | | |
Collapse
|
43
|
Mehrotra PT, Grant AJ, Siegel JP. Synergistic effects of IL-7 and IL-12 on human T cell activation. The Journal of Immunology 1995. [DOI: 10.4049/jimmunol.154.10.5093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Abstract
We have previously demonstrated that human rIL-12 alone can augment the development of cytotoxic activity in stimulated CD8+ T cells. The present study was undertaken to examine the interactions of rIL-7 and rIL-12 on human peripheral blood T cell activation and CTL differentiation. Purified T lymphocytes were pulsed overnight with immobilized alpha-CD3 and then cultured for 3 additional days with IL-7 and/or IL-12. The combination of IL-7 and IL-12 synergistically enhanced the proliferation of either fresh CD3+ T cells or an IL-2-dependent CD4+ T cell line, Kit-225-K6. This synergy was seen on both subsets of T cells; however, CD8+ T cells were usually more responsive to IL-7 and IL-12 at lower concentrations than were CD4+ T cells. Furthermore, these cytokines additively/synergistically augmented the cytotoxic activity of CD8+ T cells. Abs to IL-2 and IL-2R alpha blocked the synergistic effect on proliferation of CD4+ T cells, but had a minimal effect on the synergistic response of the proliferative and cytotoxic activity of CD8+ T cells. Examination of the effects of IL-7 and IL-12 on the expression of IL-12 receptor on T cells revealed an increase in the subunit of IL-12R by IL-7 as determined by flow cytometric analysis. We analyzed the effects on IFN-gamma production by CD8+ T cells and found that IL-7 alone did not induce detectable levels of IFN-gamma production but together with IL-12 it synergistically enhanced the production of IFN-gamma. We also found that IFN-gamma was probably not required for enhanced CTL activity of CD8+ T cells, because Ab to human IFN-gamma did not block additive/synergistic effects of either cytokine. The synergistic stimulatory activity of IL-7 and IL-12 may be of significance in vivo and may provide an alternative mechanism of stimulating T cells for use in immunotherapy.
Collapse
Affiliation(s)
- P T Mehrotra
- Laboratory of Cellular Immunology, Food and Drug Administration, Rockville, MD 20852, USA
| | - A J Grant
- Laboratory of Cellular Immunology, Food and Drug Administration, Rockville, MD 20852, USA
| | - J P Siegel
- Laboratory of Cellular Immunology, Food and Drug Administration, Rockville, MD 20852, USA
| |
Collapse
|
44
|
|
45
|
Puri RK, Mehrotra PT, Leland P, Kreitman RJ, Siegel JP, Pastan I. A chimeric protein comprised of IL-4 and Pseudomonas exotoxin is cytotoxic for activated human lymphocytes. J Immunol 1994; 152:3693-700. [PMID: 8144944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
IL4-Pseudomonas exotoxin (IL4-PE4E) is a chimeric molecule in which human IL-4 is genetically fused to the mutated binding domain of Pseudomonas exotoxin. This molecule binds specifically to human IL-4 receptor-bearing cells. IL4-PE4E was extremely cytotoxic to highly purified anti-CD3-activated CD8+ T lymphocytes. The cytotoxic activity of this molecule was dependent on the activation state of CD8+ T cells: 3- and 4-day activated T cells were very susceptible to the cytotoxic activity of IL4-PE4E compared with 0- to 2-day activated cells. PHA-activated lymphocytes and PBL activated in mixed lymphocyte reaction were also highly sensitive to IL4-PE4E. CD16+ and/or CD56+ highly purified NK cells or highly purified, IL-2-activated NK cells were also very sensitive to the cytotoxic effect of IL4-PE4E. IL-2-activated LAK cells had little susceptibility after 1 day but were very sensitive to IL4-PE4E after 3 days. The cytotoxic effects of IL4-PE4E were mediated through a ligand receptor interaction because excess rIL-4 abrogated these effects as did a neutralizing Ab to human IL-4. A chimeric mutant protein that can bind to IL-4 receptors but lacks the ability to inhibit protein synthesis was not cytotoxic to activated lymphocytes. The IL4-PE4E-mediated cytotoxicity of activated T cells correlated with the level of expression of IL-4 receptors on these cells. CD8+ T cells activated for 3 days expressed the highest density of IL-4 receptors compared with 1- or 2-day activated cells. Among two chimeric toxins tested only IL4-PE4E was cytotoxic to 2-day anti-CD3-activated CD8+ T lymphocytes, whereas IL6-PE4E was not active at all. These studies suggest that human IL4 toxin could be a potent agent for the elimination of activated lymphocytes in allograft rejection, some autoimmune diseases, or treatment of lymphomas and leukemias.
Collapse
Affiliation(s)
- R K Puri
- Division of Cellular and Gene Therapies, Food and Drug Administration, Bethesda, MD 20892
| | | | | | | | | | | |
Collapse
|
46
|
Puri RK, Mehrotra PT, Leland P, Kreitman RJ, Siegel JP, Pastan I. A chimeric protein comprised of IL-4 and Pseudomonas exotoxin is cytotoxic for activated human lymphocytes. The Journal of Immunology 1994. [DOI: 10.4049/jimmunol.152.7.3693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
IL4-Pseudomonas exotoxin (IL4-PE4E) is a chimeric molecule in which human IL-4 is genetically fused to the mutated binding domain of Pseudomonas exotoxin. This molecule binds specifically to human IL-4 receptor-bearing cells. IL4-PE4E was extremely cytotoxic to highly purified anti-CD3-activated CD8+ T lymphocytes. The cytotoxic activity of this molecule was dependent on the activation state of CD8+ T cells: 3- and 4-day activated T cells were very susceptible to the cytotoxic activity of IL4-PE4E compared with 0- to 2-day activated cells. PHA-activated lymphocytes and PBL activated in mixed lymphocyte reaction were also highly sensitive to IL4-PE4E. CD16+ and/or CD56+ highly purified NK cells or highly purified, IL-2-activated NK cells were also very sensitive to the cytotoxic effect of IL4-PE4E. IL-2-activated LAK cells had little susceptibility after 1 day but were very sensitive to IL4-PE4E after 3 days. The cytotoxic effects of IL4-PE4E were mediated through a ligand receptor interaction because excess rIL-4 abrogated these effects as did a neutralizing Ab to human IL-4. A chimeric mutant protein that can bind to IL-4 receptors but lacks the ability to inhibit protein synthesis was not cytotoxic to activated lymphocytes. The IL4-PE4E-mediated cytotoxicity of activated T cells correlated with the level of expression of IL-4 receptors on these cells. CD8+ T cells activated for 3 days expressed the highest density of IL-4 receptors compared with 1- or 2-day activated cells. Among two chimeric toxins tested only IL4-PE4E was cytotoxic to 2-day anti-CD3-activated CD8+ T lymphocytes, whereas IL6-PE4E was not active at all. These studies suggest that human IL4 toxin could be a potent agent for the elimination of activated lymphocytes in allograft rejection, some autoimmune diseases, or treatment of lymphomas and leukemias.
Collapse
Affiliation(s)
- R K Puri
- Division of Cellular and Gene Therapies, Food and Drug Administration, Bethesda, MD 20892
| | - P T Mehrotra
- Division of Cellular and Gene Therapies, Food and Drug Administration, Bethesda, MD 20892
| | - P Leland
- Division of Cellular and Gene Therapies, Food and Drug Administration, Bethesda, MD 20892
| | - R J Kreitman
- Division of Cellular and Gene Therapies, Food and Drug Administration, Bethesda, MD 20892
| | - J P Siegel
- Division of Cellular and Gene Therapies, Food and Drug Administration, Bethesda, MD 20892
| | - I Pastan
- Division of Cellular and Gene Therapies, Food and Drug Administration, Bethesda, MD 20892
| |
Collapse
|
47
|
Abstract
This article describes the drug approval process at the Center for Biologics Evaluation and Research (CBER), FDA, for cytokines and growth factors that would be licensed for clinical use in the U.S.A. CBER is responsible for setting policy, providing guidance to industry and to academic investigators as they develop and evaluate these new products, and for recommendations about the approvability of license applications. Product development generally parallels clinical development, and the expectations at each stage of the IND (Investigational New Drug) process are discussed. FDA involvement continues beyond licensure to the post marketing phase. The goal is to assure that new cytokines and growth factors are safe and effective and available in a timely manner.
Collapse
Affiliation(s)
- K D Weiss
- Office of Therapeutics, Center for Biologics Evaluation and Review, Food and Drug Administration, Bethesda, MD 20892
| | | | | |
Collapse
|
48
|
Abstract
It has previously been shown that murine sarcoma cells express high-affinity IL-4 receptors (IL-4R) which are internalized after binding to the ligand (Puri et al., Cancer Res 1991; 51:3011-7). We have also reported that human renal cell carcinoma cells express high-affinity IL-4R, and IL-4 inhibits tumour growth in vitro (Obiri et al., J Clin Invest 1993; 91:88). In this study we investigated the expression and function of IL-4R on other human solid tumours. Human melanoma, ovarian carcinoma and breast carcinoma cell lines were assessed for the cell surface expression of IL-4R by radio-ligand receptor binding and for IL-4R gene expression by Northern blot analysis. Primary cultures of mesothelioma and neurofibrosarcoma cells were similarly investigated. Human melanoma, ovarian carcinoma and breast carcinoma cell lines expressed IL-4R on their cell surface with a dissociation constant (Kd) of 140-549 pM. These tumour lines expressed a single 4 kb species of mRNA for IL-4R. Similarly, primary cultures of mesothelioma and neurofibrosarcoma cells were positive for the IL-4R mRNA by Northern blot analysis. Fresh, non-cultured mesothelioma and neurofibrosarcoma tumour sections were also positive for the presence of IL-4R as determined by immunohistochemistry of frozen sections using anti-IL-4R antibody. In order to study possible functions of IL-4R, we evaluated the effects of IL-4 on cell growth and its effect on MHC antigen expression in the presence or absence of interferon-gamma (IFN-gamma). In tissue culture, IL-4 reduced the growth of tumour cell lines and primary cell cultures studied. IL-4 had very little effect on MHC class I antigen expression on ovarian, breast and melanoma cell lines; however, MHC class II (HLA-DR) expression was enhanced on melanoma and breast carcinoma cells. IL-4 also enhanced the IFN-gamma-induced class II expression on melanoma and breast carcinoma cells. Taken together, our observations indicate that IL-4R are expressed on a variety of human solid tumours and these receptors may be functional. IL-4 alone and in combination with IFN-gamma may play a role in host immune response against cancers.
Collapse
Affiliation(s)
- N I Obiri
- Division of Cellular and Gene Therapies, FDA, Bethesda, MD 20892
| | | | | | | |
Collapse
|
49
|
Affiliation(s)
- D A Kessler
- Office of the Commissioner, Food and Drug Administration, Rockville, Md
| | | | | | | | | | | |
Collapse
|
50
|
Mehrotra PT, Wu D, Crim JA, Mostowski HS, Siegel JP. Effects of IL-12 on the generation of cytotoxic activity in human CD8+ T lymphocytes. The Journal of Immunology 1993. [DOI: 10.4049/jimmunol.151.5.2444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
We have studied the effects of human rIL-12 on the proliferation and generation of cytotoxic activity in human CTL precursors. Purified human blood CD8+ T lymphocytes were stimulated overnight with immobilized alpha-CD3 and cultured 3 to 4 additional days under various conditions. The addition of IL-12 resulted in a marked (10- to 20-fold), dose-dependent, augmentation of cytotoxicity per cell with a smaller (2-fold) increase in cell number. IL-12 augmentation of proliferation and cytotoxicity of CD8+ T cells was not inhibited by a mAb to the p55 subunit of the IL-2 receptor (alpha-Tac) at a concentration sufficient to block the activity of exogenously added IL-2, indicating that the activity of IL-12 did not require IL-2. Addition of IL-12 at the time of alpha-CD3 activation or 1 day later was highly effective at augmenting cytotoxicity, whereas delayed addition of IL-12 (day 2 or 3) resulted in a smaller increase in CTL activity with no increase in cell number. IL-12 at all doses tested synergized with low dose IL-2 in inducing the proliferation and differentiation of CD8+ T cells. The synergistic effect was not blocked by adding neutralizing serum to IFN-gamma. In contrast to this synergistic effect, IL-12 significantly inhibited the proliferation observed in the presence of higher concentrations of IL-2 (4,500 and 13,500 pg/ml). An inhibitory effect of IL-12 was also observed when IL-12 was added to CD8+ T lymphocytes 3 days subsequent to activation with alpha-CD3 and IL-2. This broad set of potent effects of IL-12 on CD8+ T cell responses suggests that IL-12 may play an important immunoregulatory role on CTL development in vivo and may be a useful tool for manipulating this process in vivo for investigational and immunotherapeutic purposes.
Collapse
Affiliation(s)
- P T Mehrotra
- Laboratory of Cellular Immunology, Food and Drug Administration, Bethesda, MD 20892
| | - D Wu
- Laboratory of Cellular Immunology, Food and Drug Administration, Bethesda, MD 20892
| | - J A Crim
- Laboratory of Cellular Immunology, Food and Drug Administration, Bethesda, MD 20892
| | - H S Mostowski
- Laboratory of Cellular Immunology, Food and Drug Administration, Bethesda, MD 20892
| | - J P Siegel
- Laboratory of Cellular Immunology, Food and Drug Administration, Bethesda, MD 20892
| |
Collapse
|