scholarly journals Esterase Activity is Affected by Genetics, Age, Insecticide Exposure, and Viral Infection in the Honey Bee, Apis mellifera

2018 ◽  
Author(s):  
Frank D. Rinkevich ◽  
Joseph W. Margotta ◽  
Michael Simone-Finstrom ◽  
Lilia I. de Guzman ◽  
Kristen B. Healy
Keyword(s):  
Viral Infection ◽  
Honey Bee ◽  
Honey Bees ◽  
Esterase Activity ◽  
Pesticide Exposure ◽  
Mite Infestation ◽  
Activity Levels ◽  
Varroa Mite ◽  
Genetic Stock ◽  
Insecticide Exposure

AbstractNon-target impacts of insecticide treatments are a major public and environmental concern, particularly in contemporary beekeeping. Therefore, it is important to understand the physiological mechanisms contributing to insecticide sensitivity in honey bees. In the present studies, we sought to evaluate the role of esterases as the source of variation in insecticide sensitivity. To address this question, the following objectives were completed: 1) Evaluated esterase activity among honey bee stocks, 2) Assessed the correlation of esterase activity with changes in insecticide sensitivity with honey bee age, 3) Established if esterases can be used as a biomarker of insecticide exposure, and 4) Examined the effects of Varroa mite infestation and viral infection on esterase activity.Results indicated that honey bees have a dynamic esterase capacity that is influenced by genetic stock and age. However, there was no consistent connection of esterase activity with insecticide sensitivity across genetic stocks or with age, suggests other factors are more critical for determining insecticide sensitivity. The trend of increased esterase activity with age in honey bees suggests this physiological transition is consistent with enhanced metabolic rate with age. The esterase inhibition with naled but not phenothrin or clothianidin indicates that reduced esterase activity levels may only be reliable for sublethal doses of organophosphate insecticides. The observation that viral infection, but not Varroa mite infestation, reduced esterase activity shows viruses have extensive physiological impacts. Taken together, these data suggest that honey bee esterase activity toward these model substrates may not correlate well with insecticide sensitivity. Future studies include identification of esterase substrates and inhibitors that are better surrogates of insecticide detoxification in honey bees as well as investigation on the usefulness of esterase activity as a biomarker of pesticide exposure, and viral infection.

scholarly journals Molecular Assessment of Genes Linked to Immune Response Traits of Honey Bees in Conventional and Organically Managed Apiaries

Insects ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 637
Author(s):  
Shalom C. Siebert ◽  
Lambert H. B. Kanga ◽  
Sheikh M. Basha ◽  
Jesusa C. Legaspi
Keyword(s):  
Gene Expression ◽  
Immune Response ◽  
Superoxide Dismutase ◽  
Young Adult ◽  
Honey Bee ◽  
Honey Bees ◽  
Mite Infestation ◽  
Varroa Mite ◽  
Mite Infestations ◽  
Organically Managed

Honey bees are of great economic importance, not only for honey production but also for crop pollination. However, honey bee populations continue to decline mainly due to exposure to pesticides, pathogens and beekeeping practices. In this study, total soluble protein was measured, total RNA was extracted and first-strand cDNAs were generated. Quantitative PCR was used to assess the relative expression (transcript abundances) of immune function-related genes in honey bees collected from organically and conventionally managed hives. Honey bees collected from conventionally managed hives with 0% Varroa mite infestation levels displayed an upregulated expression of the prophenoloxidase gene (cellular defense). Similarly, honey bees collected from organically managed hives had increased levels of the vitellogenin gene (immune function and longevity). The gene expression for malvolio (sucrose responsiveness) was highest in organically managed hives with 0% Varroa mite infestations. Young adult bees collected from organically managed hives with 5% Varroa mite infestation levels had upregulated expressions of the gene spaetzle, whereas bees from similarly infested, conventionally managed hives did not, suggesting that honey bees from organically managed hives could mount an immune response. In young adult bees collected from organically managed hives only, the expression of the immune deficiency gene (antimicrobial defense) was upregulated. The relative gene expression for superoxide dismutase 1 increased in young adult bees collected from hives with 5% Varroa mite infestation levels as expected. However, for superoxide dismutase 2, there was a high level of gene expression in adult bees from both conventionally managed hives with 0% Varroa mite infestation levels and organically managed hives with 5% Varroa mite infestations. The gene CYP9Q3 (pesticide detoxification) that metabolizes coumaphos and fluvalinate was upregulated in adult bees collected from organically managed bees. Overall, these findings provide useful insights into the genetic response of honey bees to some environmental stressors and could be an important component of best beekeeping practices that intend to enhance honey bee health.

scholarly journals Varroa jacobsoni infestation of adult Africanized and Italian honey bees (Apis mellifera) in mixed colonies in Brazil

1999 ◽  
Vol 22 (3) ◽  
pp. 321-323 ◽  
Author(s):  
Geraldo Moretto ◽  
Leonidas João de Mello Jr.
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Honey Bees ◽  
Mite Infestation ◽  
Varroa Jacobsoni ◽  
Africanized Honey Bees ◽  
African Honey Bees ◽  
Africanized Bees ◽  
Bee Colonies ◽  
Different Levels

Different levels of infestation with the mite Varroa jacobsoni have been observed in the various Apis mellifera races. In general, bees of European races are more susceptible to the mite than African honey bees and their hybrids. In Brazil honey bee colonies are not treated against the mite, though apparently both climate and bee race influence the mite infestation. Six mixed colonies were made with Italian and Africanized honey bees. The percentage infestation by this parasite was found to be significantly lower in adult Africanized (1.69 ± 0.44) than Italian bees (2.79 ± 0.65). This ratio was similar to that found in Mexico, even though the Africanized bees tested there had not been in contact with varroa, compared to more than 20 years of the coexistence in Brazil. However, mean mite infestation in Brazil on both kinds of bees was only about a third of that found in Mexico.

scholarly journals Neonicotinoid Clothianidin reduces honey bee immune response and contributes to Varroa mite proliferation

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Desiderato Annoscia ◽  
Gennaro Di Prisco ◽  
Andrea Becchimanzi ◽  
Emilio Caprio ◽  
Davide Frizzera ◽  
...  
Keyword(s):  
Immune Responses ◽  
Honey Bee ◽  
Honey Bees ◽  
Varroa Destructor ◽  
Negative Impact ◽  
Asymptomatic Infection ◽  
Varroa Mite ◽  
Deformed Wing Virus ◽  
Synergistic Interactions ◽  
Parasitic Mite

AbstractThe neonicotinoid Clothianidin has a negative impact on NF-κB signaling and on immune responses controlled by this transcription factor, which can boost the proliferation of honey bee parasites and pathogens. This effect has been well documented for the replication of deformed wing virus (DWV) induced by Clothianidin in honey bees bearing an asymptomatic infection. Here, we conduct infestation experiments of treated bees to show that the immune-suppression exerted by Clothianidin is associated with an enhanced fertility of the parasitic mite Varroa destructor, as a possible consequence of a higher feeding efficiency. A conceptual model is proposed to describe the synergistic interactions among different stress agents acting on honey bees.

scholarly journals Diagnosis of Varroa Mite (Varroa destructor) and Sustainable Control in Honey Bee (Apis mellifera) Colonies—A Review

Diversity ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 243 ◽  
Author(s):  
Aleš Gregorc ◽  
Blair Sampson
Keyword(s):  
Apis Mellifera ◽  
Organic Acids ◽  
Essential Oils ◽  
Honey Bee ◽  
Varroa Destructor ◽  
Mite Infestation ◽  
Varroa Mite ◽  
Mite Control ◽  
Bee Colonies ◽  
Reliable Methods

Determining varroa mite infestation levels in honey bee colonies and the proper method and time to perform a diagnosis are important for efficient mite control. Performing a powdered sugar shake or counting mites that drop from combs and bees onto a hive bottom board are two reliable methods for sampling varroa mite to evaluate the efficacy of an acaricide treatment. This overview summarizes studies that examine the efficacy of organic acids and essential oils, mite monitoring, and brood interruption for integrated varroa mite control in organic beekeeping.

scholarly journals Honey Bee (Hymenoptera: Apidea) Pollen Forage in a Highly Cultivated Agroecosystem: Limited Diet Diversity and Its Relationship to Virus Resistance

2020 ◽  
Vol 113 (3) ◽  
pp. 1062-1072 ◽  
Author(s):  
Ge Zhang ◽  
Ashley L St. Clair ◽  
Adam Dolezal ◽  
Amy L Toth ◽  
Matthew O’Neal
Keyword(s):  
Viral Infection ◽  
Honey Bee ◽  
Honey Bees ◽  
Agricultural Landscapes ◽  
Diet Diversity ◽  
Immune Health ◽  
Pollen Traps ◽  
Abundance And Diversity ◽  
High Level ◽  
The Impact

Abstract Intensified agriculture reduces natural and seminatural habitats and plant diversity, reducing forage available to honey bees (Apis mellifera L. [Hymenoptera: Apidea]). In agricultural landscapes of Iowa, United States, we studied the impact of extrinsic agricultural intensification on the availability of pollen for honey bees by placing colonies next to soybean fields surrounded by either a low or high level of cultivation. The abundance and diversity of pollen returned to a colony were estimated by placing pollen traps on bee colonies during the summer and fall of 2015 and 2016. We observed no difference in abundance and diversity of pollen collected by colonies in either landscape, but abundance varied over time with significantly less collected in September. We explored if the most commonly collected pollen from these landscapes had the capacity to support honey bee immune health by testing if diets consisting of these pollens improved bee resistance to a viral infection. Compared to bees denied pollen, a mixture of pollen from the two most common plant taxa (Trifolium spp. L. [Fabales: Fabaceae] and Chimaechrista fasciculata (Michx.) Greene [Fabales: Fabaceae]) significantly reduced honey bee mortality induced by viral infection. These data suggest that a community of a few common plants was favored by honey bees, and when available, could be valuable for reducing mortality from a viral infection. Our data suggest a late season shortage of pollen may be ameliorated by additions of fall flowering plants, like goldenrod (Solidago spp. L. [Asterales: Asteraceae]) and sunflower (Helianthus, Heliopsis, and Silphium spp. [Asterales: Asteraceae]), as options for enhancing pollen availability and quality for honey bees in agricultural landscapes.

scholarly journals Wild pollinator activities negatively related to honey bee colony densities in urban context

2019 ◽  
Author(s):  
Lise Ropars ◽  
Isabelle Dajoz ◽  
Colin Fontaine ◽  
Audrey Muratet ◽  
Benoît Geslin
Keyword(s):  
Honey Bee ◽  
Honey Bees ◽  
Urban Areas ◽  
Pesticide Exposure ◽  
Floral Resources ◽  
Strong Increase ◽  
Pollinator Visitation ◽  
Pollinator Decline ◽  
Bee Colony ◽  
Honey Bee Colony

AbstractAs pollinator decline is increasingly reported in natural and agricultural environments, cities are perceived as shelters for pollinators because of low pesticide exposure and high floral diversity throughout the year. This has led to the development of environmental policies supporting pollinators in urban areas. However, policies are often restricted to the promotion of honey bee colony installations, which resulted in a strong increase in apiary numbers in cities. Recently, competition for floral resources between wild pollinators and honey bees has been highlighted in semi-natural contexts, but whether urban beekeeping could impact wild pollinators remains unknown. Here, we show that in the city of Paris (France), wild pollinator visitation rates is negatively correlated to honey bee colony densities present in the surrounding (500m – slope = −0.614; p = 0.001 – and 1000m – slope = −0.489; p = 0.005). More particularly, large solitary bees and beetles were significantly affected at 500m (respectively slope = −0.425, p = 0.007 and slope = - 0.671, p = 0.002) and bumblebees were significantly affected at 1000m (slope = - 0.451, p = 0.012). Further, lower interaction evenness in plant-pollinator networks was observed with honey bee colony densities within 1000 meter buffers (slope = −0.487, p = 0.008). Finally, honey bees tended to focus their foraging activity on managed rather than spontaneous plant species (student t-test, p = 0.001) whereas wild pollinators equally visited managed and spontaneous species. We advocate responsible practices mitigating the introduction of high density of hives in urban environments. Future studies are needed to deepen our knowledge about the potential negative interactions between wild and domesticated pollinators.

scholarly journals Norwegian honey bees surviving Varroa destructor mite infestations by means of natural selection

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3956 ◽  
Author(s):  
Melissa A.Y. Oddie ◽  
Bjørn Dahle ◽  
Peter Neumann
Keyword(s):  
Natural Selection ◽  
Reproductive Success ◽  
Honey Bee ◽  
Honey Bees ◽  
Varroa Destructor ◽  
Apis Cerana ◽  
Mite Infestation ◽  
Colony Losses ◽  
Key Factor ◽  
Colony Survival

Background Managed, feral and wild populations of European honey bee subspecies, Apis mellifera, are currently facing severe colony losses globally. There is consensus that the ectoparasitic mite Varroa destructor, that switched hosts from the Eastern honey bee Apis cerana to the Western honey bee A. mellifera, is a key factor driving these losses. For >20 years, breeding efforts have not produced European honey bee colonies that can survive infestations without the need for mite control. However, at least three populations of European honey bees have developed this ability by means of natural selection and have been surviving for >10 years without mite treatments. Reduced mite reproductive success has been suggested as a key factor explaining this natural survival. Here, we report a managed A. mellifera population in Norway, that has been naturally surviving consistent V. destructor infestations for >17 years. Methods Surviving colonies and local susceptible controls were evaluated for mite infestation levels, mite reproductive success and two potential mechanisms explaining colony survival: grooming of adult worker bees and Varroa Sensitive Hygiene (VSH): adult workers specifically detecting and removing mite-infested brood. Results Mite infestation levels were significantly lower in surviving colonies and mite reproductive success was reduced by 30% when compared to the controls. No significant differences were found between surviving and control colonies for either grooming or VSH. Discussion Our data confirm that reduced mite reproductive success seems to be a key factor for natural survival of infested A. mellifera colonies. However, neither grooming nor VSH seem to explain colony survival. Instead, other behaviors of the adult bees seem to be sufficient to hinder mite reproductive success, because brood for this experiment was taken from susceptible donor colonies only. To mitigate the global impact of V. destructor, we suggest learning more from nature, i.e., identifying the obviously efficient mechanisms favored by natural selection.

scholarly journals Honey Bee Exposure to Pesticides: A Four-Year Nationwide Study

Insects ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 13 ◽  
Author(s):  
Nancy Ostiguy ◽  
Frank A. Drummond ◽  
Kate Aronstein ◽  
Brian Eitzer ◽  
James D. Ellis ◽  
...  
Keyword(s):  
Honey Bee ◽  
Honey Bees ◽  
Pesticide Exposure ◽  
Flowering Plant ◽  
Simultaneous Occurrence ◽  
Modes Of Action ◽  
Pollen Sample ◽  
One Year ◽  
Flowering Plant Species ◽  
Wax Comb

Pollinators, including honey bees, are responsible for the successful reproduction of more than 87% of flowering plant species: they are thus vital to ecosystem health and agricultural services world-wide. To investigate honey bee exposure to pesticides, 168 pollen samples and 142 wax comb samples were collected from colonies within six stationary apiaries in six U.S. states. These samples were analyzed for evidence of pesticides. Samples were taken bi-weekly when each colony was active. Each apiary included thirty colonies, of which five randomly chosen colonies in each apiary were sampled for pollen. The pollen samples were separately pooled by apiary. There were a total of 714 detections in the collected pollen and 1008 detections in collected wax. A total of 91 different compounds were detected: of these, 79 different pesticides and metabolites were observed in the pollen and 56 were observed in the wax. In all years, insecticides were detected more frequently than were fungicides or herbicides: one third of the detected pesticides were found only in pollen. The mean (standard deviation (SD)) number of detections per pooled pollen sample varied by location from 1.1 (1.1) to 8.7 (2.1). Ten different modes of action were found across all four years and nine additional modes of action occurred in only one year. If synergy in toxicological response is a function of simultaneous occurrence of multiple distinct modes of action, then a high frequency of potential synergies was found in pollen and wax-comb samples. Because only pooled pollen samples were obtained from each apiary, and these from only five colonies per apiary per year, more data are needed to adequately evaluate the differences in pesticide exposure risk to honey bees among colonies in the same apiary and by year and location.

scholarly journals Combined Toxicity of Insecticides and Fungicides Applied to California Almond Orchards to Honey Bee Larvae and Adults

Insects ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 20 ◽  
Author(s):  
Andrea Wade ◽  
Chia-Hua Lin ◽  
Colin Kurkul ◽  
Erzsébet Ravasz Regan ◽  
Reed M. Johnson
Keyword(s):  
Larval Development ◽  
Honey Bee ◽  
Honey Bees ◽  
Pesticide Exposure ◽  
Larval Mortality ◽  
Combined Toxicity ◽  
Pollination Services ◽  
Almond Orchards ◽  
Honey Bee Larvae

Beekeepers providing pollination services for California almond orchards have reported observing dead or malformed brood during and immediately after almond bloom—effects that they attribute to pesticide exposure. The objective of this study was to test commonly used insecticides and fungicides during almond bloom on honey bee larval development in a laboratory bioassay. In vitro rearing of worker honey bee larvae was performed to test the effect of three insecticides (chlorantraniliprole, diflubenzuron, and methoxyfenozide) and three fungicides (propiconazole, iprodione, and a mixture of boscalid-pyraclostrobin), applied alone or in insecticide-fungicide combinations, on larval development. Young worker larvae were fed diets contaminated with active ingredients at concentration ratios simulating a tank-mix at the maximum label rate. Overall, larvae receiving insecticide and insecticide-fungicide combinations were less likely to survive to adulthood when compared to the control or fungicide-only treatments. The insecticide chlorantraniliprole increased larval mortality when combined with the fungicides propiconazole or iprodione, but not alone; the chlorantraniliprole-propiconazole combination was also found to be highly toxic to adult workers treated topically. Diflubenzuron generally increased larval mortality, but no synergistic effect was observed when combined with fungicides. Neither methoxyfenozide nor any methoxyfenozide-fungicide combination increased mortality. Exposure to insecticides applied during almond bloom has the potential to harm honey bees and this effect may, in certain instances, be more damaging when insecticides are applied in combination with fungicides.

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