1
|
Malinski KH, Elizabeth Moore M, Kingsolver JG. Heat stress and host-parasitoid interactions: lessons and opportunities in a changing climate. CURRENT OPINION IN INSECT SCIENCE 2024; 64:101225. [PMID: 38936473 DOI: 10.1016/j.cois.2024.101225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 05/30/2024] [Accepted: 06/19/2024] [Indexed: 06/29/2024]
Abstract
Ongoing climate change is increasing the frequency and magnitude of high-temperature events (HTEs), causing heat stress in parasitoids and their hosts. We argue that HTEs and heat stress should be viewed in terms of the intersecting life cycles of host and parasitoid. Recent studies illustrate how the biological consequences of a given HTE may vary dramatically depending on its timing within these lifecycles. The temperature sensitivity of host manipulation by parasitoids, and by viral endosymbionts of many parasitoids, can contribute to differing responses of hosts and parasitoids to HTEs. In some cases, these effects can result in reduced parasitoid success and increased host herbivory and may disrupt the ecological interactions between hosts and parasitoids. Because most studies to date involve endoparasitoids of aphid or lepidopteran hosts in agricultural systems, our understanding of heat responses of host-parasitoid interactions in natural systems is quite limited.
Collapse
Affiliation(s)
| | - Megan Elizabeth Moore
- Agricultural Research Service, United States Department of Agriculture, Robert W. Holley Center, 538 Tower Road, Ithaca, NY 14850, USA
| | - Joel G Kingsolver
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA.
| |
Collapse
|
2
|
Colombo FC, Maciel RMA, Deniz M, Neves PMOJ, de Freitas Bueno A. Emergence Response of Telenomus podisi (Hymenoptera: Scelionidae) to Field Temperature Originated from Colonies Reared at Different Temperature Regimes. NEOTROPICAL ENTOMOLOGY 2023; 52:493-499. [PMID: 36859651 DOI: 10.1007/s13744-023-01035-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 02/16/2023] [Indexed: 05/13/2023]
Abstract
We studied the impact of field temperature on the emergence of Telenomus podisi Ashmead (Hymenoptera: Scelionidae) after being released as either protected (encapsulated) or unprotected pupae close to adult emergence. Two independent bioassays (protected pupae vs. unprotected pupae) were carried out in a randomized block experimental design in a 2 (parasitoid rearing temperature regimes) ×4 (release positions within plant canopy) factorial scheme. One of the T. podisi colonies was reared at a constant temperature (25 °C) and 12:12 h L:D (Light: Dark) photoperiod. The second T. podisi colony was reared at fluctuating temperatures (20 °C during 12 h D and 30 °C during 12 h of L). Each bioassay had five replicates. Each replicate contained 40 pupae from each rearing temperature and release position within plant canopy. Parasitoid pupae were released in the bottom third, middle third, or upper third of the plant's canopy, as well as between planting lines. Each bioassay was repeated six times (in different plant developmental stages: R1, R2, R3, R4, R5 and R6). There was no difference in emergence of parasitoids between colonies reared at different temperatures after exposure to field conditions. Emergence of T. podisi was reduced after pupae exposure to temperatures above 35 °C in the field, regardless of the rearing temperature. Telenomus podisi tolerates temperature fluctuations for emergence as long as they fit the optimal range (20 to 30 °C).
Collapse
Affiliation(s)
| | | | - Matheus Deniz
- Depto de Produção Animal E Medicina Veterinária Preventiva, Faculdade de Medicina Veterinária, UNESP, Botucatu, SP, Brazil
| | | | | |
Collapse
|
3
|
Weber ID, Garcia AG, de Freitas Bueno A, de Oliveira RC, Godoy WAC. Release strategies of Telenomus podisi for control of Euschistus heros: a computational modeling approach. PEST MANAGEMENT SCIENCE 2022; 78:4544-4556. [PMID: 35821565 DOI: 10.1002/ps.7074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 06/02/2022] [Accepted: 07/12/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND The egg-parasitoid wasp Telenomus podisi has received attention as a biological-control agent for one of the most important soybean pests in Brazil, the stink bug Euschistus heros. As yet, no studies have conclusively established strategies for the release of T. podisi. We developed a computational model using cellular automata in the C programming language to investigate release strategies for T. podisi in soybean crops, in order to optimize the use of these wasps in managing E. heros, assuming a two-dimensional grid of cells corresponding to a soybean field. RESULTS The release strategies capable of maintaining an E. heros population below the Economic Threshold level involved releasing a total of at least 15 000 female parasitoids per hectare, in three or four releases of 5000 or more (equivalent to approximately 7142 or more male and female parasitoids per hectare, assuming a sex ratio of 0.70). A 25-m spacing between release points or strips was indicated. The model is very sensitive to the variation in the number of parasitoids per release and in the number of releases, but little sensitive to the release mode and spacing values. CONCLUSION The theoretical results produced by the computational model are expected to guide future field studies to improve T. podisi release plans for managing E. heros in soybeans. Therefore, we recommend the release strategy of three to four releases of 5000 or more female parasitoids per hectare, at points or strips spaced 25 m apart, to be tested in field experiments for proper implementation by producers. © 2022 Society of Chemical Industry.
Collapse
Affiliation(s)
- Igor Daniel Weber
- Department of Entomology and Acarology, Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba, Brazil
| | - Adriano Gomes Garcia
- Department of Entomology and Acarology, Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba, Brazil
| | | | - Regiane Cristina de Oliveira
- Department of Plant Protection, Faculty of Agronomic Sciences, São Paulo State University (UNESP), School of Agriculture, Botucatu, Brazil
| | - Wesley Augusto Conde Godoy
- Department of Entomology and Acarology, Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba, Brazil
| |
Collapse
|
4
|
Zhang X, He B, Monticelli LS, Du W, Ruan C, Desneux N, Zhang J. Gradually Increasing the Temperature Reduces the Diapause Termination Time of Trichogramma dendrolimi While Increasing Parasitoid Performance. INSECTS 2022; 13:720. [PMID: 36005345 PMCID: PMC9409125 DOI: 10.3390/insects13080720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/21/2022] [Accepted: 08/02/2022] [Indexed: 06/15/2023]
Abstract
Trichogramma dendrolimi Matsumura is widely used as a biological control agent of many lepidopteran pests. Diapause has been used as an effective method to preserve the Trichogramma products during mass rearing production. However, it currently takes at least 70 days to break diapause, and we tested whether gradually increasing the temperature instead of using constant temperature could reduce the time of diapause termination and offer a higher flexibility to Trichogramma producers. The diapause termination rates of individuals kept at different conditions were measured, and five groups for which diapause termination rate reached the 95% were selected to test five biological parameters, including the number of eggs parasitized, the parasitism and emergence rates, the female sex ratio, the wing deformation rate, and the parasitoid longevity. Compared to the currently used procedure (70 days at 3 °C), treatments with at least two different temperatures resulted in higher parasitism and emergence rates while keeping the other parameters constant. The treatment that consisted of at least two different temperatures preceded by only 55 days of induction period had the highest population trend index, meaning that the population under these conditions grows more rapidly. Our results demonstrate that gradually increasing temperature allows T. dendrolimi to complete diapause earlier than at present while increasing its potential pest control capacity and providing additional flexibility in mass production of T. dendrolimi.
Collapse
Affiliation(s)
- Xue Zhang
- Engineering Research Center of Natural Enemies, Institute of Biological Control, Jilin Agricultural University, Changchun 130118, China
| | - Bingxin He
- Engineering Research Center of Natural Enemies, Institute of Biological Control, Jilin Agricultural University, Changchun 130118, China
| | | | - Wenmei Du
- Engineering Research Center of Natural Enemies, Institute of Biological Control, Jilin Agricultural University, Changchun 130118, China
| | - Changchun Ruan
- Engineering Research Center of Natural Enemies, Institute of Biological Control, Jilin Agricultural University, Changchun 130118, China
| | - Nicolas Desneux
- Université Côte d’Azur, INRAE, CNRS, UMR ISA, 06600 Nice, France
| | - Junjie Zhang
- Engineering Research Center of Natural Enemies, Institute of Biological Control, Jilin Agricultural University, Changchun 130118, China
| |
Collapse
|
5
|
Cutler GC, Amichot M, Benelli G, Guedes RNC, Qu Y, Rix RR, Ullah F, Desneux N. Hormesis and insects: Effects and interactions in agroecosystems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 825:153899. [PMID: 35181361 DOI: 10.1016/j.scitotenv.2022.153899] [Citation(s) in RCA: 53] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/09/2022] [Accepted: 02/11/2022] [Indexed: 06/14/2023]
Abstract
Insects in agroecosystems contend with many stressors - e.g., chemicals, heat, nutrient deprivation - that are often encountered at low levels. Exposure to mild stress is now well known to induce hormetic (stimulatory) effects in insects, with implications for insect management, and ecological structure and function in agroecosystems. In this review, we examine the major ecological niches insects occupy or guilds to which they belong in agroecosystems and how hormesis can manifest within and across these groups. The mechanistic underpinnings of hormesis in insects are starting to become established, explaining the many phenotypic hormetic responses observed in insect reproduction, development, and behavior. Whereas potential effects on insect populations are well supported in laboratory experiments, field-based hypothesis-driven research on hormesis is greatly lacking. Furthermore, because most ecological paradigms are founded within the context of communities, entomological agroecologists interested in hormesis need to 'level up' and test hypotheses that explore effects on species interactions, and community structure and functioning. Embedded in this charge is to continue experimentation on herbivorous pest species while shifting more focus towards insect natural enemies, pollinators, and detritivores - guilds that play crucial roles in highly functioning agroecosystems that have been understudied in hormesis research. Important areas for future insect agroecology research on hormesis are discussed.
Collapse
Affiliation(s)
- G Christopher Cutler
- Department of Plant, Food, and Environmental Sciences, Faculty of Agriculture, Dalhousie University, PO Box 550, Truro, NS B2N 5E3, Canada.
| | - Marcel Amichot
- Université Côte d'Azur, INRAE, CNRS, UMR ISA, 06000 Nice, France.
| | - Giovanni Benelli
- Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124 Pisa, Italy.
| | - Raul Narciso C Guedes
- Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG 36570-900, Brazil.
| | - Yanyan Qu
- Institute of Plant Protection, Beijing Academy of Agriculture and Forestry Science, Beijing 100097, China.
| | - Rachel R Rix
- Department of Plant, Food, and Environmental Sciences, Faculty of Agriculture, Dalhousie University, PO Box 550, Truro, NS B2N 5E3, Canada.
| | - Farman Ullah
- Department of Plant Biosecurity, College of Plant Protection, China Agricultural University, Beijing 100193, China.
| | - Nicolas Desneux
- Université Côte d'Azur, INRAE, CNRS, UMR ISA, 06000 Nice, France.
| |
Collapse
|
6
|
Wang J, Li S, Yang J, Guo M, Dai H, Ramirez-Romero R, Jin Z, Wang S. The Fitness of Mass Rearing Food on the Establishment of Chrysopa pallens in a Banker Plant System under Fluctuating Temperature Conditions. INSECTS 2021; 12:1014. [PMID: 34821814 PMCID: PMC8619634 DOI: 10.3390/insects12111014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/29/2021] [Accepted: 11/05/2021] [Indexed: 11/17/2022]
Abstract
Banker plant systems can be used to sustain a reproducing population of biological control agents (BCAs) within a crop, thus providing long-term pest suppression. The founder population of natural enemies in banker plant systems is usually mass-reared on factitious hosts. Thus, a better understanding of the population fitness and pest control performance of mass-reared BCAs in the field is crucial when developing integrated pest management (IPM) strategies. In this study, we determined the fitness of the generalist predator, Chrysopa pallens (Hemiptera: Chrysopidae) ever cultured on different food sources (i.e., mass rearing food, Corcyra cephalonica eggs, and aphid food, Megoura japonica) preying on Aphis craccivora in a banker plant system in a greenhouse based on Chi's age-stage, two-sex life table analysis method. The life tables and predation rate parameters of C. pallens were not significantly different between both treatments under fluctuating temperature conditions. Corcyracephalonica eggs did not significantly weaken the performances of C. pallens in a Vicia faba-A. craccivora banker plant system compared to aphids. In conclusion, C. cephalonica eggs can be used for the mass production of C. pallens as the founder population in a banker plant system. Moreover, linking the life table data with the predation rate is an effective strategy for evaluating mass rearing programs in establishing banker plant systems.
Collapse
Affiliation(s)
- Jie Wang
- Institute of Entomology, College of Agriculture, Yangtze University, Jingzhou 434020, China;
- Institute of Plant & Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China;
| | - Shu Li
- Institute of Plant & Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China;
| | - Jun Yang
- Institute for the Control of Agrochemicals, Ministry of Agriculture and Rural Affairs, Beijing 100125, China; (J.Y.); (M.G.)
| | - Mingcheng Guo
- Institute for the Control of Agrochemicals, Ministry of Agriculture and Rural Affairs, Beijing 100125, China; (J.Y.); (M.G.)
| | - Huijie Dai
- College of Agriculture and Environment, Weifang University of Science & Technology, Shouguang 262700, China;
| | - Ricardo Ramirez-Romero
- Biological Control Laboratory, Department of Agricultural Production, CUCBA, University of Guadalajara, Zapopan 317300, Mexico;
| | - Zhenyu Jin
- Institute of Entomology, College of Agriculture, Yangtze University, Jingzhou 434020, China;
| | - Su Wang
- Institute of Plant & Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China;
| |
Collapse
|
7
|
Grande MLM, de Queiroz AP, Gonçalves J, Hayashida R, Ventura MU, de Freitas Bueno A. Impact of Environmental Variables on Parasitism and Emergence of Trichogramma pretiosum, Telenomus remus and Telenomus podisi. NEOTROPICAL ENTOMOLOGY 2021; 50:605-614. [PMID: 33876392 DOI: 10.1007/s13744-021-00874-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 03/19/2021] [Indexed: 06/12/2023]
Abstract
Environmental variables may markedly influence egg parasitoid performance and must be considered when choosing the best release strategy. Thus, this study aimed to investigate the effects of light, temperature, soil moisture, and precipitation on the emergence and parasitism of parasitoid releases of unprotected and encapsulated pupae. The presence of light favored the parasitism of Trichogramma pretiosum Riley, 1879, and Telenomus remus (Nixon, 1937) but did not impact the parasitism of Telenomus podisi (Ashmead, 1893). The release strategy adopted (release of encapsulated or unprotected pupae) also impacted the results. On one hand, card capsules gave protection against rainfall, limited to 10 mm regarding Tr. pretiosum, while on the other hand, card capsules led to a reduction in the number of captured adults for Te. podisi at 25°C and 30°C. Therefore, Tr. pretiosum, Te. remus, and Te. podisi can be released using both encapsulated and unprotected pupae, with advantages and disadvantages for each strategy, depending on each studied environmental variable. In addition, parasitoid pupae should be released so that the majority emerge during daylight, especially for Te. remus and Tr. pretiosum, since parasitism was greatly reduced in dark environments. Telenomus podisi is not affected by this variable as it demonstrated similar parasitism in light and dark environments.
Collapse
Affiliation(s)
- Marcela Laiz Mora Grande
- Programa de Pós-Graduação em Agronomia, Depto de Agronomia, Univ Estadual de Londrina, UEL, Londrina, PR, Brazil
| | - Ana Paula de Queiroz
- Programa de Pós-Graduação em Entomologia, Depto de Zoologia, Univ Federal do Paraná, UFPR, Curitiba, PR, Brazil
| | - Jaciara Gonçalves
- Programa de Pós-Graduação em Entomologia, Depto de Zoologia, Univ Federal do Paraná, UFPR, Curitiba, PR, Brazil
| | - Rafael Hayashida
- Programa de Pós-Graduação em Entomologia, Depto de Zoologia, Univ Federal do Paraná, UFPR, Curitiba, PR, Brazil
| | - Maurício Ursi Ventura
- Programa de Pós-Graduação em Agronomia, Depto de Agronomia, Univ Estadual de Londrina, UEL, Londrina, PR, Brazil
| | | |
Collapse
|
8
|
Braz ÉC, Bueno ADF, Colombo FC, de Queiroz AP. Temperature Impact on Telenomus podisi Emergence in Field Releases of Unprotected and Encapsulated Parasitoid Pupae. NEOTROPICAL ENTOMOLOGY 2021; 50:462-469. [PMID: 33694074 DOI: 10.1007/s13744-021-00857-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 01/18/2021] [Indexed: 05/26/2023]
Abstract
This work aimed to evaluate the influence of temperature on the emergence of Telenomus podisi throughout the soybean development cycle, using encapsulated and unprotected pupae releases, in four different possible locations where pupae can be deposited during release. The trial was carried out in a randomized block design in a 2 × 4 factorial scheme: two parasitoid pupae release strategies (encapsulated and unprotected) × four pupae locations (between soybean lines of planting, bottom third, middle third, or upper third of plant canopy) with 5 replicates. There were no significant interactions between the studied factors. In the vegetative stage (V2 and V9), a smaller percentage of emergence of parasitoid adults was observed between soybean lines of planting (37.1% and 23.4% for V2 and V9 , respectively). The highest maximum temperatures were recorded between the soybean lines, with the greatest variations in maximum and minimum temperatures (55.2°C and 21.3°C) in V2 and (52.8°C and 23.9°C) in V9. In the reproductive stages (R1, R4, and R7), the observed temperatures were lower when compared to those observed in the vegetative stages (V2 and V9), with no difference in the emergence of parasitoid adults, which was above 70% in stage R1 and above 80% in R4 and R7. Regarding the pupae (encapsulated or unprotected), both allowed similar adult emergence. Therefore, it can be concluded that both unprotected and encapsulated pupae can be released, but those releases during the soybean vegetative development stage should be avoided due to the high temperatures to which pupae can be exposed.
Collapse
Affiliation(s)
| | - Adeney de Freitas Bueno
- Empresa Brasileira de Pesquisa Agropecuária (Embrapa Soja), Caixa Postal 231, Londrina, Paraná, CEP 86001-970, Brazil.
| | | | | |
Collapse
|
9
|
Le Lann C, van Baaren J, Visser B. Dealing with predictable and unpredictable temperatures in a climate change context: the case of parasitoids and their hosts. J Exp Biol 2021; 224:224/Suppl_1/jeb238626. [PMID: 33627468 DOI: 10.1242/jeb.238626] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The Earth's climate is changing at a rapid pace. To survive in increasingly fluctuating and unpredictable environments, species can either migrate or evolve through rapid local adaptation, plasticity and/or bet-hedging. For small ectotherm insects, like parasitoids and their hosts, phenotypic plasticity and bet-hedging could be critical strategies for population and species persistence in response to immediate, intense and unpredictable temperature changes. Here, we focus on studies evaluating phenotypic responses to variable predictable thermal conditions (for which phenotypic plasticity is favoured) and unpredictable thermal environments (for which bet-hedging is favoured), both within and between host and parasitoid generations. We then address the effects of fluctuating temperatures on host-parasitoid interactions, potential cascading effects on the food web, as well as biological control services. We conclude our review by proposing a road map for designing experiments to assess if plasticity and bet-hedging can be adaptive strategies, and to disentangle how fluctuating temperatures can affect the evolution of these two strategies in parasitoids and their hosts.
Collapse
Affiliation(s)
- Cécile Le Lann
- Université de Rennes, CNRS, ECOBIO (écosystèmes, biodiversité, évolution) - UMR 6553, 263 Avenue du Général Leclerc, 35042 Rennes, France
| | - Joan van Baaren
- Université de Rennes, CNRS, ECOBIO (écosystèmes, biodiversité, évolution) - UMR 6553, 263 Avenue du Général Leclerc, 35042 Rennes, France
| | - Bertanne Visser
- Evolution and Ecophysiology Group, Biodiversity Research Centre, Earth and Life Institute, UCLouvain, 1348 Louvain-la-Neuve, Belgium
| |
Collapse
|
10
|
Chen L, Enkegaard A, Sørensen JG. Temperature Affects Biological Control Efficacy: A Microcosm Study of Trichogramma achaeae. INSECTS 2021; 12:insects12020095. [PMID: 33499426 PMCID: PMC7912409 DOI: 10.3390/insects12020095] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/20/2021] [Accepted: 01/20/2021] [Indexed: 12/15/2022]
Abstract
Simple Summary The performance of biological control agents (BCAs) under field conditions is of importance to successfully suppress pests following release. However, the quality of BCAs is usually evaluated with laboratory measurements under controlled conditions, which has been shown unable to predict the performance in complex field conditions. In this study, we quantified the quality of the parasitoid Trichogramma achaeae in microcosms at four constant temperatures and evaluated its ability to locate and parasitise pest eggs. We also compared parasitisation efficiency with fecundity as determined under laboratory conditions. We found the biological control efficacy as determined in our microcosms was strongly regulated by temperature and was unlikely to be predicted by laboratory fecundity. These findings suggest that more complex assays, including behavioural responses, might be developed to demonstrate the field quality of BCAs. Abstract Current quality control of mass-reared biological control agents (BCAs) is usually performed in the laboratory and often fails to include behavioural aspects of the BCAs. As a result, the use of efficacy measurements determined solely under laboratory conditions to predict field efficacy can be questioned. In this study, microcosms were designed to estimate biological control efficacy (realised parasitisation efficiency) of Trichogramma achaeae Nagaraja and Nagarkatti (Hymenoptera: Trichogrammatidae) parasitising Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs across the operational temperature range (15–30 °C). Temperature greatly affected the success of females in finding and parasitising E. kuehniella eggs, with parasitisation being reduced at 15 and 20 °C, as both the percentage of parasitised host eggs and the percentage of leaves per plant with parasitised host eggs decreased sharply compared with higher temperatures. Graphing previous data on laboratory fecundity against parasitisation efficiency shows that the laboratory-measured fecundity of T. achaeae was unlikely to predict field efficacy across temperatures. Results also showed that leaf side had no effect on the preference of T. achaeae in parasitising E. kuehniella eggs; however, T. achaeae preferred to lay their eggs on the top tier of plants. These findings suggest that more complex assays, which include behavioural responses, might be developed for optimised quality control of BCAs intended for field application.
Collapse
Affiliation(s)
- Long Chen
- Department of Agroecology, Aarhus University, 4200 Slagelse, Denmark; (L.C.); (A.E.)
- Department of Biology, Aarhus University, 8000 Aarhus, Denmark
| | - Annie Enkegaard
- Department of Agroecology, Aarhus University, 4200 Slagelse, Denmark; (L.C.); (A.E.)
| | - Jesper Givskov Sørensen
- Department of Biology, Aarhus University, 8000 Aarhus, Denmark
- Correspondence: ; Tel.: +45-87156532
| |
Collapse
|
11
|
Affiliation(s)
- E M G Fontes
- Embrapa Recursos Genéticos e Biotecnologia, PQEB s/n°, CEP 71510-230, Brasília, DF, Brazil.
| | - R Laumann
- Embrapa Recursos Genéticos e Biotecnologia, PQEB s/n°, CEP 71510-230, Brasília, DF, Brazil
| |
Collapse
|