1
|
Bartling MT, Brandt A, Hollert H, Vilcinskas A. Current Insights into Sublethal Effects of Pesticides on Insects. Int J Mol Sci 2024; 25:6007. [PMID: 38892195 PMCID: PMC11173082 DOI: 10.3390/ijms25116007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 05/25/2024] [Accepted: 05/27/2024] [Indexed: 06/21/2024] Open
Abstract
The effect of pesticides on insects is often discussed in terms of acute and chronic toxicity, but an important and often overlooked aspect is the impact of sublethal doses on insect physiology and behavior. Pesticides can influence various physiological parameters of insects, including the innate immune system, development, and reproduction, through a combination of direct effects on specific exposed tissues and the modification of behaviors that contribute to health and reproductive success. Such behaviors include mobility, feeding, oviposition, navigation, and the ability to detect pheromones. Pesticides also have a profound effect on insect learning and memory. The precise effects depend on many different factors, including the insect species, age, sex, caste, physiological condition, as well as the type and concentration of the active ingredients and the exposure route. More studies are needed to assess the effects of different active ingredients (and combinations thereof) on a wider range of species to understand how sublethal doses of pesticides can contribute to insect decline. This review reflects our current knowledge about sublethal effects of pesticides on insects and advancements in the development of innovative methods to detect them.
Collapse
Affiliation(s)
- Merle-Theresa Bartling
- Institute for Insect Biotechnology, Justus Liebig University of Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany;
| | - Annely Brandt
- Bee Institute Kirchhain, Landesbetrieb Landwirtschaft Hessen, Erlenstr. 9, 35274 Kirchhain, Germany;
| | - Henner Hollert
- Department Evolutionary Ecology & Environmental Toxicology, Goethe University Frankfurt, Max-von-Laue-Str. 13, 60438 Frankfurt am Main, Germany;
- Department Environmental Media Related Ecotoxicology, Fraunhofer Institute for Molecular Biology and Applied Ecology, Auf dem Aberg 1, 57392 Schmallenberg, Germany
- LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG), Senckenberganlage 25, 60325 Frankfurt, Germany
| | - Andreas Vilcinskas
- Institute for Insect Biotechnology, Justus Liebig University of Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany;
- LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG), Senckenberganlage 25, 60325 Frankfurt, Germany
- Branch of Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology, Ohlebergsweg 12, 35392 Giessen, Germany
| |
Collapse
|
2
|
Bovier M, Camenzind DW, Brown AF, Jeker L, Retschnig G, Neumann P, Straub L. Colony environment and absence of brood enhance tolerance to a neonicotinoid in winter honey bee workers, Apis mellifera. ECOTOXICOLOGY (LONDON, ENGLAND) 2024:10.1007/s10646-024-02758-8. [PMID: 38780664 DOI: 10.1007/s10646-024-02758-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/09/2024] [Indexed: 05/25/2024]
Abstract
In eusocial insects, worker longevity is essential to ensure colony survival in brood-free periods. Trade-offs between longevity and other traits may render long-living workers in brood-free periods more susceptible to pesticides compared to short-lived ones. Further, colony environment (e.g., adequate nutrition) may enable workers to better cope with pesticides, yet data comparing long vs. short-living workers and the role of the colony environment for pesticide tolerance are scarce. Here, we show that long-living honey bee workers, Apis mellifera, are less susceptible to the neonicotinoid thiamethoxam than short-lived workers, and that susceptibility was further reduced when workers were acclimatized under colony compared to laboratory conditions. Following an OECD protocol, freshly-emerged workers were exposed to thiamethoxam in summer and winter and either acclimatized within their colony or in the laboratory. Mortality and sucrose consumption were measured daily and revealed that winter workers were significantly less susceptible than summer workers, despite being exposed to higher thiamethoxam dosages due to increased food consumption. Disparencies in fat body activity, which is key for detoxification, may explain why winter bees were less susceptible. Furthermore, colony acclimatization significantly reduced susceptibility towards thiamethoxam in winter workers likely due to enhanced protein nutrition. Brood absence and colony environment seem to govern workers' ability to cope with pesticides, which should be considered in risk assessments. Since honey bee colony losses occur mostly over winter, long-term studies assessing the effects of pesticide exposure on winter bees are required to better understand the underlying mechanisms.
Collapse
Affiliation(s)
- Manon Bovier
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Domenic W Camenzind
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Andrew F Brown
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- University of Freiburg, Freiburg, Switzerland
| | - Lukas Jeker
- Swiss Bee Research Centre, Agroscope, Bern, Switzerland
| | - Gina Retschnig
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Peter Neumann
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Lars Straub
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
- Faculty of Science, Energy and Environment, King Mongkut's University of Technology North Bangkok, Rayong Campus, Rayong, Thailand.
- Centre for Ecology, Evolution, and Behaviour, Department of Biological Sciences, Royal Holloway University of London, Egham, UK.
| |
Collapse
|
3
|
Bartlett LJ, Alparslan S, Bruckner S, Delaney DA, Menz JF, Williams GR, Delaplane KS. Neonicotinoid exposure increases Varroa destructor (Mesostigmata: Varroidae) mite parasitism severity in honey bee colonies and is not mitigated by increased colony genetic diversity. JOURNAL OF INSECT SCIENCE (ONLINE) 2024; 24:20. [PMID: 38805648 PMCID: PMC11132139 DOI: 10.1093/jisesa/ieae056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 03/21/2024] [Accepted: 04/29/2024] [Indexed: 05/30/2024]
Abstract
Agrochemical exposure is a major contributor to ecological declines worldwide, including the loss of crucial pollinator species. In addition to direct toxicity, field-relevant doses of pesticides can increase species' vulnerabilities to other stressors, including parasites. Experimental field demonstrations of potential interactive effects of pesticides and additional stressors are rare, as are tests of mechanisms via which pollinators tolerate pesticides. Here, we controlled honey bee colony exposure to field-relevant concentrations of 2 neonicotinoid insecticides (clothianidin and thiamethoxam) in pollen and simultaneously manipulated intracolony genetic heterogeneity. We showed that exposure increased rates of Varroa destructor (Anderson and Trueman) parasitism and that while increased genetic heterogeneity overall improved survivability, it did not reduce the negative effect size of neonicotinoid exposure. This study is, to our knowledge, the first experimental field demonstration of how neonicotinoid exposure can increase V. destructor populations in honey bees and also demonstrates that colony genetic diversity cannot mitigate the effects of neonicotinoid pesticides.
Collapse
Affiliation(s)
- Lewis J Bartlett
- Center for the Ecology of Infectious Diseases, Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
- Department of Entomology, University of Georgia, Athens, GA 30602, USA
| | - Suleyman Alparslan
- Department of Entomology & Plant Pathology, Auburn University, Auburn, AL 36849, USA
| | - Selina Bruckner
- Department of Entomology & Plant Pathology, Auburn University, Auburn, AL 36849, USA
| | - Deborah A Delaney
- Department of Entomology & Wildlife Ecology, University of Delaware, Newark, DE 27695-7613, USA
| | - John F Menz
- Department of Entomology & Wildlife Ecology, University of Delaware, Newark, DE 27695-7613, USA
| | - Geoffrey R Williams
- Department of Entomology & Plant Pathology, Auburn University, Auburn, AL 36849, USA
| | - Keith S Delaplane
- Department of Entomology, University of Georgia, Athens, GA 30602, USA
| |
Collapse
|
4
|
Lin Z, Shen S, Wang K, Ji T. Biotic and abiotic stresses on honeybee health. Integr Zool 2024; 19:442-457. [PMID: 37427560 DOI: 10.1111/1749-4877.12752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Honeybees are the most critical pollinators providing key ecosystem services that underpin crop production and sustainable agriculture. Amidst a backdrop of rapid global change, this eusocial insect encounters a succession of stressors during nesting, foraging, and pollination. Ectoparasitic mites, together with vectored viruses, have been recognized as central biotic threats to honeybee health, while the spread of invasive giant hornets and small hive beetles also increasingly threatens colonies worldwide. Cocktails of agrochemicals, including acaricides used for mite treatment, and other pollutants of the environment have been widely documented to affect bee health in various ways. Additionally, expanding urbanization, climate change, and agricultural intensification often result in the destruction or fragmentation of flower-rich bee habitats. The anthropogenic pressures exerted by beekeeping management practices affect the natural selection and evolution of honeybees, and colony translocations facilitate alien species invasion and disease transmission. In this review, the multiple biotic and abiotic threats and their interactions that potentially undermine bee colony health are discussed, while taking into consideration the sensitivity, large foraging area, dense network among related nestmates, and social behaviors of honeybees.
Collapse
Affiliation(s)
- Zheguang Lin
- Apicultural Research Institute, College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Siyi Shen
- Apicultural Research Institute, College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Kang Wang
- Apicultural Research Institute, College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Ting Ji
- Apicultural Research Institute, College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| |
Collapse
|
5
|
Malladi S, Sukkar D, Bonnefoy A, Falla-Angel J, Laval-Gilly P. Imidacloprid and acetamiprid synergistically downregulate spaetzle and myD88 of the Toll pathway in haemocytes of the European honeybee (Apis mellifera). ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2023; 104:104323. [PMID: 37995888 DOI: 10.1016/j.etap.2023.104323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 11/13/2023] [Accepted: 11/18/2023] [Indexed: 11/25/2023]
Abstract
Pollinator health has been of critical concern over the last few decades. The prevalence of the honeybee Colony Collapse Disorder (CCD), changing climate, and the rise of vector-borne honeybee diseases by Varroa destructor, have played a major role in the rapid decline of global honeybee populations. Honeybees are environmentally and economically significant actors in biodiversity. The impact of agricultural practices, such as pesticide use, has exacerbated the negative effects on honeybees. We demonstrate the synergistic effect of cocktails of the neonicotinoids imidacloprid and acetamiprid on honeybee haemocytes. Two genes responsible for critical immune responses, spaetzle and myD88, are consistently dysregulated following exposure to either neonicotinoid alone or as a mixture with or without an immune challenge. The 2018 ban of neonicotinoids in Europe, followed by the 2020 reauthorisation of imidacloprid in France and the current consideration to reinstate acetamiprid underscores the need to evaluate their cumulative impact on honeybee health.
Collapse
Affiliation(s)
| | - Dani Sukkar
- Université de Lorraine, INRAE, LSE, F-54000 Nancy, France; Université de Lorraine, IUT Thionville-Yutz, Plateforme de Recherche, Transfert de Technologie et Innovation (PRTI), 57970 Yutz, France
| | - Antoine Bonnefoy
- Université de Lorraine, IUT Thionville-Yutz, Plateforme de Recherche, Transfert de Technologie et Innovation (PRTI), 57970 Yutz, France
| | | | | |
Collapse
|
6
|
Zhang F, Cao W, Zhang Y, Luo J, Hou J, Chen L, Yi G, Li H, Huang M, Dong L, Li X. S-dinotefuran affects the social behavior of honeybees (Apis mellifera)and increases their risk in the colony. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 196:105594. [PMID: 37945244 DOI: 10.1016/j.pestbp.2023.105594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 08/24/2023] [Accepted: 08/26/2023] [Indexed: 11/12/2023]
Abstract
The toxic effects of neonicotinoid pesticides on honeybees is a global concern, whereas little is known about the effect of stereoisomeric pesticides among honeybee social behavior. In this study, we investigated the effects of stereoisomeric dinotefuran on honeybee social behavior. We found that honeybees exhibit a preference for consuming food containing S-dinotefuran, actively engage in trophallaxis with S-dinotefuran-consuming peers, and consequently acquire higher levels of S-dinotefuran compared with R-dinotefuran. In comparison to R-dinotefuran, S-dinotefuran stimulates honeybees to elevate their body temperature, thereby attracting more peers for trophallaxis. Transcriptome analysis revealed a significant enrichment of thermogenesis pathways due to S-dinotefuran exposure. Additionally, metabolome data indicated that S-dinotefuran may enhance body temperature by promoting lipid synthesis in the lysine degradation pathway. Consequently, body temperature emerges as a key factor influencing honeybee social behavior. Our study is the first to highlight the propensity of S-dinotefuran to raise honeybee body temperature, which prompts honeybee to preferentially engage in trophallaxis with peers exhibiting higher body temperatures. This preference may lead honeybees to collect more dinotefuran-contaminated food in the wild, significantly accelerating dinotefuran transmission within a population. Proactive trophallaxis further amplifies the risk of neonicotinoid pesticide transmission within a population, making honeybees that have consumed S-dinotefuran particularly favored within their colonies. These findings may contribute to our understanding of the higher risk associated with neonicotinoid use compared with other pesticides.
Collapse
Affiliation(s)
- Fu Zhang
- Guangxi Key Laboratory of Agric-Environment and Agric-products Safety, Guangxi University, Nanning, Guangxi 530004, China
| | - Wenjing Cao
- Guangxi Key Laboratory of Agric-Environment and Agric-products Safety, Guangxi University, Nanning, Guangxi 530004, China
| | - Yongheng Zhang
- Guangxi Key Laboratory of Agric-Environment and Agric-products Safety, Guangxi University, Nanning, Guangxi 530004, China
| | - Jie Luo
- Guangxi Key Laboratory of Agric-Environment and Agric-products Safety, Guangxi University, Nanning, Guangxi 530004, China
| | - Jiangan Hou
- Guangxi Key Laboratory of Agric-Environment and Agric-products Safety, Guangxi University, Nanning, Guangxi 530004, China
| | - Lichao Chen
- Guangxi Key Laboratory of Agric-Environment and Agric-products Safety, Guangxi University, Nanning, Guangxi 530004, China
| | - Guoqiang Yi
- Guangxi Key Laboratory of Agric-Environment and Agric-products Safety, Guangxi University, Nanning, Guangxi 530004, China
| | - Honghong Li
- Guangxi Key Laboratory of Agric-Environment and Agric-products Safety, Guangxi University, Nanning, Guangxi 530004, China
| | - Mingfeng Huang
- Guangxi Key Laboratory of Agric-Environment and Agric-products Safety, Guangxi University, Nanning, Guangxi 530004, China
| | - Linxi Dong
- Guangxi Key Laboratory of Agric-Environment and Agric-products Safety, Guangxi University, Nanning, Guangxi 530004, China
| | - Xuesheng Li
- Guangxi Key Laboratory of Agric-Environment and Agric-products Safety, Guangxi University, Nanning, Guangxi 530004, China.
| |
Collapse
|
7
|
Boakye RG, Stanley DA, White B. Honey contamination from plant protection products approved for cocoa (Theobroma cacao) cultivation: A systematic review of existing research and methods. PLoS One 2023; 18:e0280175. [PMID: 37878562 PMCID: PMC10599517 DOI: 10.1371/journal.pone.0280175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 08/06/2023] [Indexed: 10/27/2023] Open
Abstract
The main component of chocolate, cocoa (Theobroma cacao), is a significant commercial agricultural plant that directly sustains the livelihoods of an estimated forty to fifty million people. The economies of many cocoa producing nations, particularly those in the developing world, are supported by cocoa export revenue. To ensure satisfactory yields, however, the plant is usually intensely treated with pesticides because it is vulnerable to disease and pest attacks. Even though pesticides help protect the cocoa plant, unintended environmental contamination is also likely. Honey, produced from nectar obtained by honeybees from flowers while foraging, can serve as a good indicator for the level of pesticide residues and environmental pesticide build-up in landscapes. Here, we use a systematic literature review to quantify the extent of research on residues of pesticides used in cocoa cultivation in honey. In 81% of the 104 studies examined for this analysis, 169 distinct compounds were detected. Imidacloprid was the most frequently detected pesticide, making neonicotinoids the most frequently found class of pesticides overall. However, in cocoa producing countries, organophosphates, organochlorines, and pyrethroids were the most frequently detected pesticides. Interestingly, only 19% of studies were carried out in cocoa producing countries. We recommend prioritizing more research in the countries that produce cocoa to help to understand the potential impact of pesticide residues linked with cocoa cultivation in honey and the environment more generally to inform better pesticide usage, human health, and environmental policies.
Collapse
Affiliation(s)
- Richard G. Boakye
- School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
- Earth Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Dara A. Stanley
- School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
- Earth Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Blanaid White
- School of Chemical Sciences, Dublin City University, Dublin, Ireland
- National Centre for Sensor Research, DCU Water Institute, Dublin City University, Dublin, Ireland
| |
Collapse
|
8
|
Sherard M, Dang QM, Reiff SC, Simpson JH, Leopold MC. On-Site Detection of Neonicotinoid Pesticides Using Functionalized Gold Nanoparticles and Halogen Bonding. ACS APPLIED NANO MATERIALS 2023; 6:8367-8381. [PMID: 37260915 PMCID: PMC10227770 DOI: 10.1021/acsanm.3c00618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 04/10/2023] [Indexed: 06/02/2023]
Abstract
Neonicotinoid (NN) pesticides have emerged globally as one of the most widely used agricultural tools for protecting crops from pest damage and boosting food production. Unfortunately, some NN compounds, such as extensively employed imidacloprid-based pesticides, have also been identified as likely endangering critical pollinating insects like honey bees. To this end, NN pesticides pose a potential threat to world food supplies. As more countries restrict or prohibit the use of NN pesticides, tools are needed to effectively and quickly identify the presence of NN compounds like imidacloprid on site (e.g., in storage areas on farms or pesticide distribution warehouses). This study represents a proof-of-concept where the colloidal properties of specifically modified gold nanoparticles (Au-NPs) able to engage in the rare intermolecular interaction of halogen bonding (XB) can result in the detection of certain NN compounds. Density functional theory and diffusion-ordered NMR spectroscopy (DOSY NMR) are used to explore the fundamental XB interactions between strong XB-donor structures and NN compounds, with the latter found to possess multiple XB-acceptor binding sites. A fundamental understanding of these XB interactions allows for the functionalization of alkanethiolate-stabilized Au-NPs, known as monolayer-protected gold clusters (MPCs), with XB-donor capability (f-MPCs). In the presence of certain NN compounds such as imidacloprid, the f-MPCs subsequently exhibit visual XB-induced aggregation that is also measured with absorption (UV-vis) spectroscopy and verified with transmission electron microscopy (TEM) imaging. The demonstrated f-MPC-aggregation detection scheme has a number of favorable attributes, including quickly reporting the presence of the NN target, requiring only micrograms of suspect material, and being highly selective for imidacloprid, the most prevalent and most important NN insecticide compound. Requiring no instrumentation, the presented methodology can be envisioned as a simple screening test in which dipping a cotton swab of an unknown powder from a surface in a f-MPC solution causes f-MPCs to aggregate and yield a preliminary indication of imidacloprid presence.
Collapse
|
9
|
Michelangeli M, Martin JM, Pinter-Wollman N, Ioannou CC, McCallum ES, Bertram MG, Brodin T. Predicting the impacts of chemical pollutants on animal groups. Trends Ecol Evol 2022; 37:789-802. [PMID: 35718586 DOI: 10.1016/j.tree.2022.05.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 05/06/2022] [Accepted: 05/23/2022] [Indexed: 12/21/2022]
Abstract
Chemical pollution is among the fastest-growing agents of global change. Synthetic chemicals with diverse modes-of-action are being detected in the tissues of wildlife and pervade entire food webs. Although such pollutants can elicit a range of sublethal effects on individual organisms, research on how chemical pollutants affect animal groups is severely lacking. Here we synthesise research from two related, but largely segregated fields - ecotoxicology and behavioural ecology - to examine pathways by which chemical contaminants could disrupt processes that govern the emergence, self-organisation, and collective function of animal groups. Our review provides a roadmap for prioritising the study of chemical pollutants within the context of sociality and highlights important methodological advancements for future research.
Collapse
Affiliation(s)
- Marcus Michelangeli
- Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, SE-901 83, Sweden; School of Biological Sciences, Monash University, Melbourne, 3800, Australia.
| | - Jake M Martin
- School of Biological Sciences, Monash University, Melbourne, 3800, Australia
| | - Noa Pinter-Wollman
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095-7246, USA
| | - Christos C Ioannou
- School of Biological Sciences, University of Bristol, Bristol BS8 1QU, UK
| | - Erin S McCallum
- Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, SE-901 83, Sweden
| | - Michael G Bertram
- Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, SE-901 83, Sweden
| | - Tomas Brodin
- Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, SE-901 83, Sweden
| |
Collapse
|
10
|
Bruckner S, Straub L, Neumann P, Williams GR. Synergistic and Antagonistic Interactions Between Varroa destructor Mites and Neonicotinoid Insecticides in Male Apis mellifera Honey Bees. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.756027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Pressures from multiple, sometimes interacting, stressors can have negative consequences to important ecosystem-service providing species like the western honey bee (Apis mellifera). The introduced parasite Varroa destructor and the neonicotinoid class of insecticides each represent important, nearly ubiquitous biotic and abiotic stressors to honey bees, respectively. Previous research demonstrated that they can synergistically interact to negatively affect non-reproductive honey bee female workers, but no data exist on how concurrent exposure may affect reproductive honey bee males (drones). This is important, given that the health of reproductive females (queens), possibly because of poor mating, is frequently cited as a major driver of honey bee colony loss. To address this, known age cohorts of drones were obtained from 12 honey bee colonies—seven were exposed to field-relevant concentrations of two neonicotinoids (4.5 ppb thiamethoxam and 1.5 ppb clothianidin) during development via supplementary pollen patties; five colonies received patties not spiked with neonicotinoids. Artificially emerged drones were assessed for natural V. destructor infestation, weighed, and then allocated to the following treatment groups: 1. Control, 2. V. destructor only, 3. Neonicotinoid only, and 4. Combined (both mites and neonicotinoid). Adult drones were maintained in laboratory cages alongside attendant workers (1 drone: 2 worker ratio) until they have reached sexual maturity after 14 days so sperm concentration and viability could be assessed. The data suggest that V. destructor and neonicotinoids interacted synergistically to negatively affect adult drone survival, but that they interacted antagonistically on emergence mass. Although sample sizes were too low to assess the effects of V. destructor and combined exposure on sperm quality, we observed no influence of neonicotinoids on sperm concentration or viability. Our findings highlight the diverse effects of concurrent exposure to stressors on honey bees, and suggest that V. destructor and neonicotinoids can severely affect the number of sexually mature adult drones available for mating.
Collapse
|