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Crane DM, Lamere CA, Moon RD, Manweiler SA. Efficacy and Nontarget Effects of a Spinosad-Based Larvicide in Minnesota Vernal Pools and Cattail Marshes. JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION 2021; 37:125-131. [PMID: 34407168 DOI: 10.2987/21-7021.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Larvicides that contain spinosad, a bacterial metabolite, are used to control mosquitoes in diverse aquatic habitats. These same habitats are home to other invertebrates, including Crustacea-fairy shrimp, isopods, and amphipods-and mollusks-fingernail clams and freshwater snails. A double-blind study evaluated the effects of Natular® G, a granular treatment containing spinosad, on spring Aedes spp. and nontarget invertebrates in vernal wetlands. Within 14 days after application, Natular G controlled larvae of spring Aedes by 53-84%, depending on species, but had no significant effects on numbers of fairy shrimp, fingernail clams, or freshwater snails. A second double-blind study evaluated effects on Coquillettidia perturbans and nontarget isopods and amphipods in cattail marshes. Treatment reduced emergence of Cq. perturbans by 25% but did not change numbers of isopods or amphipods. The 2 experiments indicate Natular G could be effective against spring Aedes in vernal wetlands, less so against Cq. perturbans in cattail marshes, and yet pose minimal risk to crustaceans and mollusks in either vernal wetlands or cattail marshes.
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Li XF, Ao SC, Shi X, Cheng JJ, Tan L, Cai QH, Tong XL, Jacobus LM. Life history of Caenis lubrica Tong and Dudgeon, 2002 (Ephemeroptera: Caenidae) in a Three Gorges Reservoir feeder stream, subtropical Central China. AQUATIC INSECTS 2021; 42:50-61. [DOI: 10.1080/01650424.2020.1867869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 12/14/2020] [Accepted: 12/15/2020] [Indexed: 06/16/2023]
Affiliation(s)
- Xian-Fu Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P.R. China
- Institute of Eastern-Himalaya Biodiversity Research, Dali University, Dali, P.R. China
- Collaborative Innovation Center for Biodiversity and Conservation in the Three Parallel Rivers Region of China, Dali University, Dali, P.R. China
- The Provincial Innovation Team of Biodiversity Conservation and Utility, Three Parallel Rivers Region from Dali University, Dali, P.R. China
- The Key Laboratory of Yunnan Education Department on Er’hai Catchment Conservation and Sustainable Development, Dali, P.R. China
| | - Si-Cheng Ao
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P.R. China
- University of Chinese Academy of Sciences, Beijing, P.R. China
| | - Xin Shi
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P.R. China
- University of Chinese Academy of Sciences, Beijing, P.R. China
| | - Jing-Jing Cheng
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P.R. China
| | - Lu Tan
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P.R. China
| | - Qing-Hua Cai
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P.R. China
| | - Xiao-Li Tong
- Department of Entomology, College of Agriculture, South China Agricultural University, Guangzhou, P.R. China
| | - Luke M. Jacobus
- Division of Science, Indiana University Purdue University Columbus, Columbus, IN, USA
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Sharma A, Sisodiya N, Tilak R, Arti Sarin RA. Laboratory evaluation of spinosad as a potential larvicide against immature forms of Aedes aegypti. JOURNAL OF MARINE MEDICAL SOCIETY 2021. [DOI: 10.4103/jmms.jmms_125_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Mendonça TP, Davi de Aquino J, Junio da Silva W, Mendes DR, Campos CF, Vieira JS, Barbosa NP, Carvalho Naves MP, Olegário de Campos Júnior E, Alves de Rezende AA, Spanó MA, Bonetti AM, Vieira Santos VS, Pereira BB, Resende de Morais C. Genotoxic and mutagenic assessment of spinosad using bioassays with Tradescantia pallida and Drosophila melanogaster. CHEMOSPHERE 2019; 222:503-510. [PMID: 30721808 DOI: 10.1016/j.chemosphere.2019.01.182] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 01/28/2019] [Accepted: 01/30/2019] [Indexed: 06/09/2023]
Abstract
Spinosad (SPN) is a naturally-occurring insecticide obtained from the fermentation process of the actinomycete Saccharopolyspora spinosa. Owing to the larvicidal action, the compound has been used in the control of Aedes aegypti. As a new insecticide commercially available in the market, few data are reported on genotoxic effects in non-target organisms. The objective of the present study was to evaluate the mutagenic effect of SPN through the Micronucleus Test in Tradescantia pallida (Trad-MCN) and using the mutation and somatic recombination test in Drosophila melanogaster (SMART). At the Trad-MCN, after acclimatization (24 h), T. pallida stems were submitted to chronic treatment with SPN at concentrations of 0.156; 0.312; 0.625; 1.25 and 2.5 g/L solution for 24 h, followed by a recovery period. In SMART, considering the third stage larvae, offspring resulting from the ST and HB crossing were placed on chronic treatment (48 h) with 0.039; 0.078 and 0.156 μg/mL of SPN solution. No mutagenic effect was observed at any of the evaluated concentrations in SMART. Additionally, SPN is more toxic after metabolism via CYP6A2 (cytochrome P450) in D. melanogaster. However, SPN at the concentrations of 0.625; 1.25 and 2.5 g/L was able to induce high frequency of micronuclei in T. pallida. Under the experimental conditions of T. pallida in the present study, SPN caused genotoxic activity.
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Affiliation(s)
- Tarcísio Paiva Mendonça
- Department of Cell Biology, Fundação Carmelitana Mário Palmério, 38500-000, Monte Carmelo, Minas Gerais, Brazil
| | - Jéssica Davi de Aquino
- Department of Cell Biology, Fundação Carmelitana Mário Palmério, 38500-000, Monte Carmelo, Minas Gerais, Brazil
| | - Weverson Junio da Silva
- Department of Cell Biology, Fundação Carmelitana Mário Palmério, 38500-000, Monte Carmelo, Minas Gerais, Brazil
| | - Daniele Ruela Mendes
- Department of Cell Biology, Fundação Carmelitana Mário Palmério, 38500-000, Monte Carmelo, Minas Gerais, Brazil
| | - Carlos Fernando Campos
- Institute of Biotechnology, Federal University of Uberlândia, Campus Umuarama, 38900-402, Uberlândia, Minas Gerais, Brazil
| | - Jéssica Soares Vieira
- Department of Cell Biology, Fundação Carmelitana Mário Palmério, 38500-000, Monte Carmelo, Minas Gerais, Brazil
| | - Nathalya Pereira Barbosa
- Institute of Biotechnology, Federal University of Uberlândia, Campus Umuarama, 38900-402, Uberlândia, Minas Gerais, Brazil
| | - Maria Paula Carvalho Naves
- Institute of Biotechnology, Federal University of Uberlândia, Campus Umuarama, 38900-402, Uberlândia, Minas Gerais, Brazil
| | | | | | - Mário Antônio Spanó
- Institute of Biotechnology, Federal University of Uberlândia, Campus Umuarama, 38900-402, Uberlândia, Minas Gerais, Brazil
| | - Ana Maria Bonetti
- Institute of Biotechnology, Federal University of Uberlândia, Campus Umuarama, 38900-402, Uberlândia, Minas Gerais, Brazil
| | - Vanessa Santana Vieira Santos
- Institute of Biotechnology, Federal University of Uberlândia, Campus Umuarama, 38900-402, Uberlândia, Minas Gerais, Brazil
| | - Boscolli Barbosa Pereira
- Institute of Biotechnology, Federal University of Uberlândia, Campus Umuarama, 38900-402, Uberlândia, Minas Gerais, Brazil; Institute of Geography, Federal University of Uberlândia, Campus Santa Mônica, 38400-902, Uberlândia, Minas Gerais, Brazil.
| | - Cássio Resende de Morais
- Institute of Biotechnology, Federal University of Uberlândia, Campus Umuarama, 38900-402, Uberlândia, Minas Gerais, Brazil
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Michaelakis A, Papachristos DP, Rumbos CI, Benelli G, Athanassiou CG. Larvicidal activity of spinosad and its impact on oviposition preferences of the West Nile vector Culex pipiens biotype molestus - A comparison with a chitin synthesis inhibitor. Parasitol Int 2019; 74:101917. [PMID: 31004804 DOI: 10.1016/j.parint.2019.04.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 04/13/2019] [Accepted: 04/17/2019] [Indexed: 12/13/2022]
Abstract
In the present study, the larvicidal activity of ageing aqueous suspensions of spinosad against larvae of Culex pipiens biotype molestus, as well as their effect on the oviposition preferences of adult gravid females were evaluated in laboratory bioassays. Spinosad was applied at its label dose and the aqueous stock suspensions were stored for various ageing intervals up to 38 days. Untreated distilled water and diflubenzuron served as negative and positive control, respectively. Stock suspensions were taken after 0, 2, 6, 8, 16, 30 and 38 days of storage for diflubenzuron and after 0, 2, 6, 8, 20 and 27 days for spinosad, and were used for the bioassays. Furthermore, the effect of spinosad on the oviposition response of Cx. p. biotype molestus gravid females was investigated in two-choice oviposition preference bioassays. Spinosad was evaluated at half of its label dose and at its label dose, whereas diflubenzuron and distilled water served as positive and negative control, respectively. Results showed that both insecticides were found highly effective for the control of Cx. p. biotype molestus larvae, for ageing intervals up to 27 and 38 days for spinosad and diflubenzuron, respectively. Spinosad acted immediately after the preparation of the insecticidal solution (LT50 = 1.5 h), whereas for aged samples, LT50 values increased with the increase of the ageing interval (LT50 = 5 days for the 27 days old sample). For diflubenzuron, ageing time increased its insecticidal activity, as for aged diflubenzuron-treated solutions, lower LT50 values were achieved. In the oviposition preference bioassays, significantly fewer egg rafts were laid in water treated with spinosad at its label dose compared to control. However, this was not the case for water treated with spinosad at half of its label dose. Oviposition Activity Index (OAI) values were always comprised between -0.3 and 0.3, showing no relevant oviposition deterrence or attraction. The results of the present study contribute to our understanding of the effect of ageing on insecticidal solutions widely used in urban areas to control Cx. p. biotype molestus. Although an important vector of high public health importance, Cx. p. biotype molestus has been scarcely studied as target of environmentally and toxicologically reduced risk insecticides, such as spinosad.
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Affiliation(s)
- Antonios Michaelakis
- Department of Entomology and Agricultural Zoology, Benaki Phytopathological Institute, 8 S. Delta Str. 14561 Kifissia, Athens, Greece
| | - Dimitrios P Papachristos
- Department of Entomology and Agricultural Zoology, Benaki Phytopathological Institute, 8 S. Delta Str. 14561 Kifissia, Athens, Greece
| | - Christos I Rumbos
- Laboratory of Entomology and Agricultural Zoology, Department of Agriculture, Crop Production and Rural Environment, University of Thessaly, Phytokou str., 38446, N. Ionia, Magnesia, Greece
| | - Giovanni Benelli
- Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124 Pisa, Italy
| | - Christos G Athanassiou
- Laboratory of Entomology and Agricultural Zoology, Department of Agriculture, Crop Production and Rural Environment, University of Thessaly, Phytokou str., 38446, N. Ionia, Magnesia, Greece.
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Ioannidis P, Simao FA, Waterhouse RM, Manni M, Seppey M, Robertson HM, Misof B, Niehuis O, Zdobnov EM. Genomic Features of the Damselfly Calopteryx splendens Representing a Sister Clade to Most Insect Orders. Genome Biol Evol 2017; 9:415-430. [PMID: 28137743 PMCID: PMC5381652 DOI: 10.1093/gbe/evx006] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/19/2017] [Indexed: 12/14/2022] Open
Abstract
Insects comprise the most diverse and successful animal group with over one million described species that are found in almost every terrestrial and limnic habitat, with many being used as important models in genetics, ecology, and evolutionary research. Genome sequencing projects have greatly expanded the sampling of species from many insect orders, but genomic resources for species of certain insect lineages have remained relatively limited to date. To address this paucity, we sequenced the genome of the banded demoiselle, Calopteryx splendens, a damselfly (Odonata: Zygoptera) belonging to Palaeoptera, the clade containing the first winged insects. The 1.6 Gbp C. splendens draft genome assembly is one of the largest insect genomes sequenced to date and encodes a predicted set of 22,523 protein-coding genes. Comparative genomic analyses with other sequenced insects identified a relatively small repertoire of C. splendens detoxification genes, which could explain its previously noted sensitivity to habitat pollution. Intriguingly, this repertoire includes a cytochrome P450 gene not previously described in any insect genome. The C. splendens immune gene repertoire appears relatively complete and features several genes encoding novel multi-domain peptidoglycan recognition proteins. Analysis of chemosensory genes revealed the presence of both gustatory and ionotropic receptors, as well as the insect odorant receptor coreceptor gene (OrCo) and at least four partner odorant receptors (ORs). This represents the oldest known instance of a complete OrCo/OR system in insects, and provides the molecular underpinning for odonate olfaction. The C. splendens genome improves the sampling of insect lineages that diverged before the radiation of Holometabola and offers new opportunities for molecular-level evolutionary, ecological, and behavioral studies.
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Affiliation(s)
- Panagiotis Ioannidis
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland.,Swiss Institute of Bioinformatics, Geneva, Switzerland
| | - Felipe A Simao
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland.,Swiss Institute of Bioinformatics, Geneva, Switzerland
| | - Robert M Waterhouse
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland.,Swiss Institute of Bioinformatics, Geneva, Switzerland
| | - Mosè Manni
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland.,Swiss Institute of Bioinformatics, Geneva, Switzerland
| | - Mathieu Seppey
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland.,Swiss Institute of Bioinformatics, Geneva, Switzerland
| | - Hugh M Robertson
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL
| | - Bernhard Misof
- Center for Molecular Biodiversity Research, Zoological Research Museum Alexander Koenig, Bonn, Germany
| | - Oliver Niehuis
- Center for Molecular Biodiversity Research, Zoological Research Museum Alexander Koenig, Bonn, Germany
| | - Evgeny M Zdobnov
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland.,Swiss Institute of Bioinformatics, Geneva, Switzerland
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Lawler SP. Environmental safety review of methoprene and bacterially-derived pesticides commonly used for sustained mosquito control. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2017; 139:335-343. [PMID: 28187397 DOI: 10.1016/j.ecoenv.2016.12.038] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 12/23/2016] [Accepted: 12/29/2016] [Indexed: 06/06/2023]
Abstract
Some pesticides are applied directly to aquatic systems to reduce numbers of mosquito larvae (larvicides) and thereby reduce transmission of pathogens that mosquitoes vector to humans and wildlife. Sustained, environmentally-safe control of larval mosquitoes is particularly needed for highly productive waters (e.g., catchment basins, water treatment facilities, septic systems), but also for other habitats to maintain control and reduce inspection costs. Common biorational pesticides include the insect juvenile hormone mimic methoprene and pesticides derived from the bacteria Bacillus thuringiensis israelensis, Lysinibacillus sphaericus and Saccharopolyspora spinosa (spinosad). Health agencies, the public and environmental groups have especially debated the use of methoprene because some studies have shown toxic effects on non-target organisms. However, many studies have demonstrated its apparent environmental safety. This review critically evaluates studies pertinent to the environmental safety of using methoprene to control mosquito larvae, and provides concise assessments of the bacterial larvicides that provide sustained control of mosquitoes. The review first outlines the ecological and health effects of mosquitoes, and distinguishes between laboratory toxicity and environmental effects. The article then interprets non-target toxicity findings in light of measured environmental concentrations of methoprene (as used in mosquito control) and field studies of its non-target effects. The final section evaluates information on newer formulations of bacterially-derived pesticides for sustained mosquito control. Results show that realized environmental concentrations of methoprene were usually 2-5µg/kg (range 2-45µg/kg) and that its motility is limited. These levels were not toxic to the vast majority of vertebrates and invertebrates tested in laboratories, except for a few species of zooplankton, larval stages of some other crustaceans, and small Diptera. Studies in natural habitats have not documented population reductions except in small Diptera. Bacterial larvicides showed good results for sustained control with similarly limited environmental effects, except for spinosad, which had broader effects on insects in mesocosms and temporary pools. These findings should be useful to a variety of stakeholders in informing decisions on larvicide use to protect public and environmental health in a 'One Health' framework.
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Affiliation(s)
- Sharon P Lawler
- Department of Entomology and Nematology, University of California, Davis One Shields Avenue, Davis, CA 95616, USA.
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Harbison JE, Henry M, Corcoran PC, Zazra D, Xamplas C. Small-Scale Trials Suggest Increasing Applications of Natular™ XRT and Natular™ T30 Larvicide Tablets May Not Improve Mosquito Reduction in Some Catch Basins. ENVIRONMENTAL HEALTH INSIGHTS 2016; 10:31-34. [PMID: 26792998 PMCID: PMC4712978 DOI: 10.4137/ehi.s36722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 11/18/2015] [Accepted: 11/20/2015] [Indexed: 06/05/2023]
Abstract
Stormwater catch basins are commonly treated with larvicides by mosquito control agencies to reduce local populations of mosquito species capable of transmitting West Nile virus. Recent evidence suggests that extended-release larvicides formulated to last up to 180 days in catch basins may not be effective in some basins due to chronic flushing, rapid dissolution, or burying of treatment in sump debris. To investigate if increasing the number of applications could improve effectiveness, a small study was performed over 13 weeks in 2015 to evaluate two extended-release larvicides (Natular™ XRT 180-day tablets and Natular™ T30 30-day tablets) and a larvicide oil (CocoBear™). Over the course of 13 weeks, three groups of eight basins were monitored for mosquitoes, each group receiving Natular™ XRT, Natular™ T30, or CocoBear™ larvicides. All basins received a single application at the beginning of the study period. Once mosquitoes in a basin surpassed the treatment threshold during weekly monitoring, an additional application of the associated larvicide was given to that basin. The number of applications during the study period ranged from 1 to 10 for CocoBear™ basins, 1 to 7 for T30 basins, and 2 to 8 for XRT basins. Overall, the average number of applications and the cost of larvicide per basin were 4.4 applications at $0.66 per Coco-Bear™ basin, 4.4 applications at $6.26 per T30 basin, and 4 applications at $16.56 per XRT basin. Basins treated with XRT and T30 needed reapplications more often than expected, yet were no more effective than CocoBear™, suggesting that increasing the frequency of application of these larvicide formulations may not provide increased mosquito reduction in some basins.
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Affiliation(s)
- Justin E. Harbison
- Department of Public Health Sciences, Loyola University Medical Center, Loyola University Chicago, Maywood, IL, USA
- North Shore Mosquito Abatement District, Northfield, IL, USA
| | - Marlon Henry
- North Shore Mosquito Abatement District, Northfield, IL, USA
| | | | - Dave Zazra
- North Shore Mosquito Abatement District, Northfield, IL, USA
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Harbison JE, Layden JE, Xamplas C, Zazra D, Henry M, Ruiz MO. Observed loss and ineffectiveness of mosquito larvicides applied to catch basins in the northern suburbs of chicago IL, 2014. ENVIRONMENTAL HEALTH INSIGHTS 2015; 9:1-5. [PMID: 25987841 PMCID: PMC4406279 DOI: 10.4137/ehi.s24311] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 03/16/2015] [Accepted: 03/18/2015] [Indexed: 06/04/2023]
Abstract
In the northeastern part of the greater Chicago metropolitan area, the North Shore Mosquito Abatement District (NSMAD) treats approximately 50,000 catch basins each season with larvicide tablets as part of its effort to reduce local populations of the West Nile virus (WNV) vector Culex pipiens. During the 2014 season, an NSMAD technician monitored a subset of 60-195 basins weekly for 18 weeks among the communities of the District for the presence of mosquitoes. Monitoring found no clear evidence in the reduction of mosquitoes with the use of larvicides, and visual inspections of 211 larvicide-treated basins found that the majority (162, 76.8%) were missing tablets 1-17 weeks after applications. This loss of treatment may be due to the rapid dissolution or flushing of larvicides and would help explain why the larvicide appeared to be ineffective.
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Affiliation(s)
- Justin E Harbison
- Department of Public Health Sciences, Loyola University Chicago, Maywood, IL, USA
| | - Jennifer E Layden
- Department of Public Health Sciences, Loyola University Chicago, Maywood, IL, USA
- Department of Medicine, Section of Infectious Diseases, Loyola University Chicago, Maywood, IL, USA
| | | | - Dave Zazra
- North Shore Mosquito Abatement District, Northfield, IL, USA
| | - Marlon Henry
- North Shore Mosquito Abatement District, Northfield, IL, USA
| | - Marilyn O’Hara Ruiz
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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Marina CF, Bond JG, Muñoz J, Valle J, Novelo-Gutiérrez R, Williams T. Efficacy and non-target impact of spinosad, Bti and temephos larvicides for control of Anopheles spp. in an endemic malaria region of southern Mexico. Parasit Vectors 2014; 7:55. [PMID: 24479683 PMCID: PMC3915226 DOI: 10.1186/1756-3305-7-55] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 01/20/2014] [Indexed: 11/20/2022] Open
Abstract
Background The larvicidal efficacy of the naturally derived insecticide spinosad, for control of immature stages of Anopheles albimanus and associated culicids, was compared to that of synthetic and biological larvicides. Effects on non-target insects were also determined. Methods A field trial was performed in replicated temporary pools during the rainy season, in southern Mexico. Pools were treated with 10 ppm a.i. spinosad (Tracer 480SC), Bti granules applied at 2 kg/ha (VectoBac WDG, ABG-6511), and 100 ml/ha temephos (50 EC), or an untreated control. Numbers of immature mosquitoes, and aquatic insects in pools were monitored for 20 weeks. Results Samples of immature mosquitoes comprised approximately 10% An. albimanus, 70% Culex spp. (mostly Cx. melanoconion and Cx. coronator) and 20% Uranotaenia lowii. The most effective larvicides were spinosad and temephos that eliminated An. albimanus in 16 out of 20 post-treatment samples, or 9 weeks of continuous control of immature stages, respectively. These larvicides resulted in 15 and 5 weeks of elimination of Culex spp., respectively, or 20 and 4 weeks of continuous elimination of U. lowii, respectively. Bti treatment provided little consistent control. Aquatic insects were recorded comprising 3 orders, 20 families, 40 genera and 44 species. Shannon diversity index values (H’) for aquatic insects were highest in the control (0.997) and Bti (0.974) treatments, intermediate in the spinosad treatment (0.638) and lowest in the temephos treatment (0.520). Severely affected non-target insects in the spinosad and temephos treated pools were predatory Coleoptera, Hemiptera and Odonata, which in the case of spinosad was likely due to the high concentration applied. Bti had little effect on aquatic insects. Conclusions The spinosad treatment retained larvicidal activity for markedly longer than expected. Spinosad is likely to be an effective tool for control of anopheline and other pool-breeding mosquitoes in tropical regions. Non-target effects of spinosad on aquatic insects merit further study, but were likely related to the concentration of the product used.
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Lawler SP, Dritz DA. Efficacy of spinosad in control of larval Culex tarsalis and chironomid midges, and its nontarget effects. JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION 2013; 29:352-357. [PMID: 24551968 DOI: 10.2987/13-6369.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Formulations of spinosad for mosquito and midge control (e.g., Natular) are derived from the Saccharopolyspora spinosa bacterium. They offer a different mode of action from other larvicides. We tested the effectiveness of single-brood (2EC) and extended-release pellet (G30) formulations against larvae of Culex tarsalis and chironomid midges, at mid- to high label rates, in wetland mesocosms. We also monitored survival of mayfly nymphs and other nontarget insects. Both formulations were effective against mosquitoes for > 4 wk and yielded excellent midge control. Spinosad caused mortality of mayflies and other nontarget insects. Spinosad was less toxic to mayflies than to targets, and effects on mayflies were undetectable after day 21. The higher toxicity for mosquitoes indicates that future research could identify rates that reduce nontarget effects while maintaining high efficacy.
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Affiliation(s)
- Sharon P Lawler
- Department of Entomology and Nematology, University of California, Davis, Davis, CA 95616, USA
| | - Deborah A Dritz
- Department of Entomology and Nematology, University of California, Davis, Davis, CA 95616, USA
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