Colony Collapse Research Articles

Possible Spillover of Pathogens between Bee Communities Foraging on the Same Floral Resource.

Simple SummaryFloral resource availability is one of the keys to preserving the health of bee communities. However, flowers also present a risk of pathogen transmission, as infected pollinators could deposit pathogens while foraging, exposing other pollinators to infection via the consumption of contaminated nectar or pollen. Here, we studied, over time, the prevalence of seven viruses in bee communities that share the same small surface of floral resource in order to assess the risk of virus spillover. In total, 2057 bee specimens from 30 species were caught, identified and checked for the presence of viruses. Specimens from the Halictidae family were the dominant wild bees. The prevalence of viruses was quite high: at least one virus was detected in 78% of the samples, and co-infections were frequent. The genetic diversity of the viruses was also investigated to look for the possible association of geographic origin or host with shared ancestry.Viruses are known to contribute to bee population decline. Possible spillover is suspected from the co-occurrence of viruses in wild bees and honey bees. In order to study the risk of virus transmission between wild and managed bee species sharing the same floral resource, we tried to maximize the possible cross-infections using Phacelia tanacetifolia, which is highly attractive to honey bees and a broad range of wild bee species. Virus prevalence was compared over two years in Southern France. A total of 1137 wild bees from 29 wild bee species (based on COI barcoding) and 920 honey bees (Apis mellifera) were checked for the seven most common honey bee RNA viruses. Halictid bees were the most abundant. Co-infections were frequent, and Sacbrood virus (SBV), Black queen cell virus (BQCV), Acute bee paralysis virus (ABPV) and Israeli acute paralysis virus (IAPV) were widespread in the hymenopteran pollinator community. Conversely, Deformed wing virus (DWV) was detected at low levels in wild bees, whereas it was highly prevalent in honey bees (78.3% of the samples). Both wild bee and honey bee virus isolates were sequenced to look for possible host-specificity or geographical structuring. ABPV phylogeny suggested a specific cluster for Eucera bees, while isolates of DWV from bumble bees (Bombus spp.) clustered together with honey bee isolates, suggesting a possible spillover.

Apis mellifera africanized queens tolerant to the neonicotinoid thiamethoxam

Interaction between bees and plants ensured success in cross-pollination crops, increasing the vigor of the species, as the production of fruits and seeds. Bees are the main pollinators of angiosperms and several crops. Among the factors related to the disappearance of bees in agricultural areas is the excessive or improper use of insecticides. However, agriculture is extremely dependent on pesticides for pest control and the neonicotinoid thiamethoxam is one of the most used insecticides. The use of these chemicals affects the pollinating bee Apis mellifera. Thus, the aim of the study was to select Africanized A. mellifera queens tolerant to thiamethoxam, producing four generations of bees kept in chronic contamination and perform tests to validate tolerance. Colonies of A. mellifera were subjected to chronic contamination by contact with thiamethoxam at a sublethal concentration of 1.65 mg a.i./L. From the surviving colonies, four generations of new queens were produced, kept in chronic contamination with thiamethoxam. Chronic contamination caused changes in the workers' behavior for 25 days. Validation of selection and tolerance was performed in vitro bioassays to verify mortality and critical electrolyte concentration (CEC). In vitro bioassays showed that there was low mortality after contamination for 24 hours by contact with thiamethoxam at 82.5 mg a.i / L. The analyzes of CEC indicate that there was an increase in gene expression in brain cells, probably as an attempt to detoxify the workers' organism by contamination with thiamethoxam. New tests need to be carried out with colonies tolerant to the neonicotinoid thiamethoxam, but these initial results indicate that these queens have potential to tolerate this neonicotinoid.

Effects of Natural Habitat Loss and Edge Effects on Wild Bees and Pollination Services in Remnant Prairies

Habitat loss and edge effects resulting from habitat fragmentation are key processes implicated in the decline of bee populations globally. Their effects on wild bees and their pollination services in natural ecosystems are poorly understood, particularly in North American prairies. Our objectives were to determine whether natural habitat loss and edge effects affect bee abundance and pollination services in the Northern Great Plains. We sampled bee abundance and pollination services along transects beginning at road or tree edges in grasslands located in Manitoba, Canada. We measured bee abundance using pan traps, and pollination services using seed-set of Brassica rapa (L.) (Brassicales: Brassicaceae) phytometers. We collected local-scale habitat data by measuring occurrence of flowering species, vegetation type, and vegetation structure, and we measured habitat amount at 1-km radii using GIS analysis of landscape cover. Increasing amounts of habitat loss resulted in declines in bee abundance, and sometimes in pollination services. Results varied with bee life-history: proximity to road edges negatively affected social bees, and litter depth had negative effects on below- ground-nesting bees. Surprisingly, few effects on bees led to corresponding impacts on pollination services. This suggests that conservation of intact natural habitat across the northern Great Plains is important for maintaining resilient and diverse bee communities, but that efforts to conserve bee populations cannot be assumed to also maintain all associated pollination services.

Simple approaches for environmental and mechanical management of the Varroa mite, Varroa destructor Anderson and Trueman (Parasitiformes: Varroidae), on the honey bee, Apis mellifera L. (Hymenoptera: Apidae) in Egypt

BackgroundVarroa mite, Varroa destructor Anderson and Trueman (Parasitiformes: Varroidae), is an ectoparasitic mite of the honey bee, Apis mellifera L. (Hymenoptera: Apidae), with a great economic importance. It is the major deadlock of apiculture development all over the world.ResultsThis work aimed to assess the effect of bee house and dark bee house on numbers of Varroa mite on white card board sheets, worker broods, and alive bees during spring and autumn of 2018 and 2019. Two types of card board for sticking the fallen Varroa mite were evaluated through winter of 2019. Keeping honey bee hives in a dark room during March and September of 2018 and 2019 for a successive 3 days resulted in a great reduction in the number of Varroa inner bee hive, i.e., on the white card board sheets, area of broods, and alive honey bee. Highest number of fallen Varroa mite on the white card board sheets was obtained in the case of using the dark bee house during March and September in 2018 and 2019, followed by keeping in a normal bee house then those fallen in the case of the open apiary.ConclusionThe dark bee house grooming behaviour increased through 3 days of dark. Environmental management of bee house and dark bee house can be promising in colony collapse disorder. Modified adhesive sheets were more efficient in this regard than the normal ones.

Antiviral Treatment Reveals a Cooperative Pathogenicity of Baculovirus and Iflavirus in Spodoptera exigua, a Lepidopteran Insect.

NPVThe beet armyworm, Spodoptera exigua, is a serious insect pest infesting various vegetable crops. Two infectious insect viruses, baculovirus and iflavirus, are known to induce epizootics in S. exigua populations. Indeed, some laboratory colonies have appeared to be covertly infected by these viruses. Diagnostic PCR tests detected two different viruses: Spodoptera exigua multiple nucleopolyhedrosis virus (SeMNPV) and iflaviruses (SeIfV1 and SeIfV2). Viral extract from dead larvae of S. exigua could infect Sf9 cells and produce occlusion bodies (OBs). Feeding OBs to asymptomatic larvae of S. exigua caused significant viral disease. Interestingly, both SeIfV1 and SeIfV2 increased their titers at late larval stages. Sterilization of laid eggs with 1% sodium hypochloride significantly reduced SeMNPV titers and increased larval survival rate. Doublestranded RNA (dsRNA) specific to SeIfV1 or SeIfV2 significantly reduced viral titers and increased larval survival rate. To continuously feed dsRNA, a recombinant Escherichia coli HT115 expressing SeIfV1-dsRNA was constructed with an L4440 expression vector. Adding this recombinant E. coli to the artificial diet significantly reduced the SeIfV1 titer and increased larval survival. These results indicate that laboratory colony collapse of S. exigua is induced by multiple viral infections. In addition, either suppression of SeMNPV or SeIfV infection significantly increased larval survival, suggesting a cooperative pathogenicity between baculovirus and iflavirus against S. exigua.

Changes in the expression of antimicrobial peptide genes in honey bees (Apis mellifera) under the influence of various pathogens.

Honey bees play an invaluable role in the ecosystem as plant pollinators. The dramatic decline in honey bee population has prompted a search for its underlying causes and effective remedy methods. Insects produce antimicrobial peptides (AMPs) which play an important role in the induced humoral immune response. The presence of apidaecin, abaecin, hymenoptaecin and defensin has been confirmed in honey bees. The expression of genes encoding these proteins is activated via two signalling pathways: toll pathway for apidaecins and defensins, and Imd pathway for abaecin and hymenoptaecin. Bee pathogens and parasites affect the expression of AMP genes, thus stimulating or inhibiting immune responses. The main causative agents of the global decline in bee populations include Varroa destructor, deformed wing virus (DWV), neonicotinoids, and microsporidian parasites of the genus Nosema. Researchers are divided over the influence of these pathogens and insecticides on the expression of AMP genes in insects. There is evidence to suggest that the age of honey bee plays an important role, and that peptides should be identified solely in the context of specific age groups. There is also a general scarcity of research into the long-term effects of immunosuppressive factors. The influence of various pathogens on the immune system of bees should be investigated to better understand their mutual relationships and to develop effective bee protection methods.

Artificial Diets Modulate Infection Rates by Nosema ceranae in Bumblebees.

Parasites alter the physiology and behaviour of their hosts. In domestic honey bees, the microsporidia Nosema ceranae induces energetic stress that impairs the behaviour of foragers, potentially leading to colony collapse. Whether this parasite similarly affects wild pollinators is little understood because of the low success rates of experimental infection protocols. Here, we present a new approach for infecting bumblebees (Bombus terrestris) with controlled amounts of N. ceranae by briefly exposing individual bumblebees to parasite spores before feeding them with artificial diets. We validated our protocol by testing the effect of two spore dosages and two diets varying in their protein to carbohydrate ratio on the prevalence of the parasite (proportion of PCR-positive bumblebees), the intensity of parasites (spore count in the gut and the faeces), and the survival of bumblebees. Overall, insects fed a low-protein, high-carbohydrate diet showed the highest parasite prevalence (up to 70%) but lived the longest, suggesting that immunity and survival are maximised at different protein to carbohydrate ratios. Spore dosage did not affect parasite infection rate and host survival. The identification of experimental conditions for successfully infecting bumblebees with N. ceranae in the lab will facilitate future investigations of the sub-lethal effects of this parasite on the behaviour and cognition of wild pollinators.

In silico prediction of chemical acute contact toxicity on honey bees via machine learning methods

In recent years, the decline of honey bees and the collapse of bee colonies have caught the attention of ecologists, and the use of pesticides is one of the main reasons for the decline. Therefore, ecological risk assessment of pesticides is essential and necessary. In silico tools, such as QSAR models can play an important role in predicting physicochemical and biological properties of chemicals. In this study, a total of 54 classification models were developed by combination of 6 machine learning methods along with 9 kinds of molecular fingerprints based on the experimental honey bees acute contact toxicity data (LD50) of 676 structurally diverse pesticides. The best model proposed was SVM algorithm combined with CDK extended fingerprint. The analysis of the applicability domain of the model successfully excluded some extreme molecules. Additionally, 9 structural alerts about honey bees acute contact toxicity were identified by information gain and substructure frequency analysis.

Impact of Varroa destructor and associated pathologies on the colony collapse disorder affecting honey bees

Varroa mite is the major threat to the western honey bee, Apis mellifera, and the cause of significant economic losses in the apiculture industry. Varroa destructor feeds on brood and adult bees being responsible for vectoring virus infections and other diseases. This study analyses the role of Varroa and other associated pathogens, such as viruses or the fungus Nosema ceranae, and their relationships regarding the viability of the bee colony. It has been carried out during one beekeeping season, with the subspecies A. m. iberiensis, commonly used in the apiculture industry of Spain. Our study shows a significant relationship between the presence of Varroa destructor and viral infection by deformed wing virus and acute bee paralysis virus. Nosema ceranae behaved as an opportunistic pathogen. In addition, this study explored a potential naturally occurring subset of peptides, responsible for the humoral immunity of the bees. The expression of the antimicrobial peptides abaecin and melittin showed a significant relationship with the levels of Varroa mite and the deformed wing virus.

General review on artificial queen rearing in honey bees

Several complications such as the poor health of the queen, injury, aging, exposure to pesticides, pathogens, parasites, colony collapse disorder, idiopathic brood disease syndrome, etc. are associated with the queen loss and ultimately loss of the colony. The technique of rearing queen bee from the one- day old totipotent larva by using grafting method is described in this review article. Various tools are used for dry, wet grafting and for rearing the honey bees. The objective of this paper is to get acquainted with the artificial queen rearing method to rear several honeybees in a short period to generate several colonies from a single colony. This method plays a significant role in generating several honeybee colonies for research work focused at the behavioural and physiological aspects of queen bee.

Understanding social resilience in honeybee colonies.

Honeybee colonies experience high losses, induced by several stressors that can result in the collapse of colonies. Experiments show what effects stressors, such as parasites, pathogens and pesticides, can have on individual honeybees as well as colonies. Although individuals may die, colonies do not always collapse from such disturbances. As a superorganism, the colony can maintain or return back to homeostasis through colony mechanisms. This capacity is defined as social resilience. When the colony faces a high stress load, this may lead to breakdown in mechanisms, loss in resilience and eventually colony collapse. Before social resilience can be measured in honeybees, we need to examine the mechanisms in colonies that allow recovery and maintenance after stressor exposure. Here, we discuss some of these mechanisms and how they affect the social resilience of honeybee colonies. Understanding social resilience in honeybees is essential to managing colony health and loss prevention.

Real-Time Monitoring of DWV-Infected Bee Foraging Behavior Following Histone Deacetylase Inhibitor Treatment

Impairment in learning and memory behaviors in bees due to pesticide exposures and pathogen infections has resulted in massive disappearance of bee populations and subsequent agricultural economic losses. One of the causes of this bee colony collapse disorder (CCD) is the infection of deformed wing virus (DWV). The present study found that sodium butyrate, a histone deacetylase inhibitor (HDACi) previously shown to reverse the detrimental effects of a nicotine-like pesticide on learning behavior and memory in bees, significantly increased the survival of bee after DWV infection and reversed the learning/memory impairment in proboscis extension response (PER) assay. A next-generation sequencing analysis revealed the gene expression profile underwent DWV infection and sodium butyrate treatment and showed that sodium butyrate affected the expression of a wide range of genes involved in diverse biological processes. Particularly, sodium butyrate could up-regulate the expression of genes involved in glycolytic process and memory formation that were down-regulated during DWV infection. As brain physiological analyses presented that sodium butyrate restored the energy supply and the production of neurotransmitter in the infected bees, a large-scale movement tracking was performed by using a wireless sensor network (WSN)-based automatic real-time monitoring system and confirmed that sodium butyrate can improve the ability of DWV-infected bees to return to their hives. In short, we demonstrated the mechanism of how epigenetic regulation can resume the memory function of honeybees and suggested strategies for applying sodium butyrate as possible solutions for reducing the incidence of CCD.

Mexican creeper, Antigonon leptopus Hook. and Arn : An effective bee forage plant to conserve honey bee

Decline in honey bee populations has become a matter of concern and their conservation is very essential to sustain essential ecosystem services. They provide making available continuous supply of floral resources is of immense value in conserving honey bees. The effectiveness of an ornamental creeper, Antigonon leptopus Hook. & Arn as a sustainable bee forage plant was evaluated. It attracts four major native species of honey bees viz., Apis cerana, A. florea, A. dorsata and Tetragonula iridipennis. The wild little bee, A. florea was the most dominant forager followed by the Indian bee, A. cerana. The plant is amenable for easy multiplication through seeds as well as cuttings and meets both aesthetic and ecological needs. Using Antigonon, different studies related to honey bees like assessing species diversity, foraging behaviour, temperature driven shifts etc. can be carried out. Popularising perennial bee flora like Antigonon would help in conserving honey bees in both natural and urban habitats. Since Antigonon attracts all species of honey bees throughout the year, it could be utilized as a potential bioindicator of honey bee populations in a given environment.

Mexican creeper, Antigonon leptopus Hook. and Arn : An effective bee forage plant to conserve honey bee


 
 
 Decline in honey bee populations has become a matter of concern and their conservation is very essential to sustain essential ecosystem services. They provide making available continuous supply of floral resources is of immense value in conserving honey bees. The effectiveness of an ornamental creeper, Antigonon leptopus Hook. & Arn as a sustainable bee forage plant was evaluated. It attracts four major native species of honey bees viz., Apis cerana, A. florea, A. dorsata and Tetragonula iridipennis. The wild little bee, A. florea was the most dominant forager followed by the Indian bee, A. cerana. The plant is amenable for easy multiplication through seeds as well as cuttings and meets both aesthetic and ecological needs. Using Antigonon, different studies related to honey bees like assessing species diversity, foraging behaviour, temperature driven shifts etc. can be carried out. Popularising perennial bee flora like Antigonon would help in conserving honey bees in both natural and urban habitats. Since Antigonon attracts all species of honey bees throughout the year, it could be utilized as a potential bioindicator of honey bee populations in a given environment.
 
 

Risk Assessment of Pesticidal Toxicity and Threats on Pollinators: A Review on Honey Bee

Pollinators play vital roles to the environment, biodiversity conservation, food security and several dimensions of global sustainable development. Honey bee is an important pollinator globally but has been exposed to increasing threats from diseases, pesticides and biotic stresses. This review paper highlights the role of honey bees as pollinators, addresses threats which influence decline of honey bees and assess pesticidal risk toxicity on non-target organisms. Decline of honey bee population is caused by several factors including habitat fragmentation, pesticidal toxicity, colony collapse disorder and climate change. Pesticidal residue and toxicity has an adverse effect which results in honey bee population decline, disturb foraging and contamination of bee products. Residues of agricultural pesticides like pyrethroid and neonicotinoid pose a serious threat on honey bee health further reducing agricultural production and diversity. Pesticidal risk assessments are carried out to study effects of pesticides on pollinators with an aim to provide measures to safeguard their abundance, diversity and health. Sustainable agriculture, effective policy and proper management can decrease pollinators' risk by helping to diversify the agriculture for pollen and nectars with reduced usage of pesticides and proper management.

Abejas y Covid-19: una regulación jurídica necesaria

La abejas llevan siglos sobrevolando los textos jurídicos. De hecho, son los únicos animales a los que los Códigos continentales dedican una atención específica y cuyo régimen jurídico ha permanecido inalterado, a pesar de los muchos cambios que se han producido en el entorno social, económico y biológico de nuestro planeta. La progresiva desaparición de las abejas junto a la profunda crisis que ha provocado el coronavirus, obliga a plantearse una nueva visión de la salud personal y colectiva, en la que la protección de la biodiversidad es ineludible. Los insectos polinizadores son clave para el mantenimiento de la salud del planeta y del equilibrio de los ecosistemas. De ellos depende nuestra alimentación y el mantenimiento de la salud, en gran medida. Este trabajo, quiere sentar las bases para una nueva consideración de las abejas en el ámbito jurídico. La UE es consciente de que la legislación relativa es insuficiente y obsoleta. Más protección de las abejas, equivale a mejor protección de la salud.

Bioremediation potential of select bacterial species for the neonicotinoid insecticides, thiamethoxam and imidacloprid

Thiamethoxam (THM) and imidacloprid (IMI), are environmentally persistent neonicotinoid insecticides which have become increasingly favored in the past decade due to their specificity as insect neurotoxicants. However, neonicotinoids have been implicated as a potential contributing factor in Colony Collapse Disorder (CCD) which affects produce production on a global scale. The present study characterizes the bioremediation potential of six bacterial species: Pseudomonas fluorescens, Pseudomonas putida, Pseudomonas aeruginosa, Alcaligenes faecalis, Escherichia coli, and Streptococcus lactis. In Phase I, we evaluated the utilization of IMI or THM as the sole carbon or nitrogen source by P. fluorescens, P. putida, and P. aeruginosa. All three species were better able to utilize THM over IMI as their sole carbon or nitrogen source. Thus, further studies proceeded with THM only. In Phase II, we assessed the kinetics of THM removal from aqueous media by the six species. Significant (p < 0.0001) reductions in 70 mg/L THM concentration were observed for P. fluorescens (67%), P. putida (65%), P. aeruginosa (52%), and A. faecalis (39%) over the 24-day study period, and for E. coli (60%) and S. lactis (12%) over the 14-day study period. The THM removal by all species followed a first-order kinetic reaction. HPLC chromatograms of P. fluorescens, P. putida, and E. coli cultures revealed that as the area of the THM peak decreased over time, the area of an unidentified metabolite peak increased. In Phase III, we examined the effect of temperature on the transformation capacity of the bacterial species which was observed at 2 ℃, 22 ℃, and 30 ℃. Maximal THM removal occurred at 30 °C for all bacterial species assessed. Identification of the metabolite is currently underway. If the metabolite is found to be less hazardous than THM, further testing will follow to evaluate the use of this bioremediation technique in the field.

Assessing the impacts of land use and climate interactions on beekeeping livelihoods in the Taita Hills, Kenya

ABSTRACT Beekeeping is commonly adopted as an additional livelihood activity that can help smallholder farmers diversify and enhance their livelihoods. However, it is unclear whether it is resilient to environmental shocks and stresses. This article investigates beekeepers’ experiences and perceptions about challenges to beekeeping in the Taita Hills Mountains, Kenya. Key findings demonstrated that beekeeping has the capacity to substantially increase household income, but there are several challenges which affect beekeeping’s sustainability considering predictions around climate and land use change. Bee population decline due to pesticide use was seen as a major challenge across the altitudinal range. In the highland areas deforestation, land use conflicts and cold weather were key issues; whereas in the lowlands water availability and the associated impacts on floral availability were the primary concerns of beekeepers.

The neonicotinoid imidacloprid alone alters the cognitive behavior in Apis mellifera L. and the combined exposure of imidacloprid and Varroa destructor mites synergistically contributes to trial attrition

Honey bee (Apis mellifera L.) populations have undergone a dramatic decline as an outcome of an increasing incidence of colony collapse disorder (CCD). The honey bee is a unique keystone species because its pollination activities are not only necessary for the viability of many flowering plant species in the wild, but are also necessary for many human agricultural practices. The increasing prevalence of CCD is a threat to the economic and nutritional security of all societies that rely on efficient pollination for large monoculture crops. Although there is ample evidence that Varroa mites, pesticides, disease, and climate change contribute to CCD, only a few studies have investigated the contribution of synergism across multiple factors to the development of CCD and CCD-like symptoms. However, there is increasing acknowledgement in the scientific community that synergism across different factors affects honey bee colony health and behavior. Here, we provide evidence that sub-lethal levels of imidacloprid neonicotinoid pesticide reduce learning and memory capabilities. Synergistic effects become apparent when Varroa mites together with imidacloprid exposure to individual bees more than doubled average mortality and attrition per trial.

Economics of Pollination

Many food crops rely on pollination by animals. Historically, wind and wild organisms provided pollination as an ecosystem service that varied across agroceological zones, cropping systems, and time. The value of these pollination services is likely substantial but has not been estimated reliably. More recently, pollination services in major crop producing regions have been provided through organized markets, primarily the rental of honey bees. The sustainability of commercially provided pollination services is being challenged by parasites, diseases, pesticide exposures, poor nutrition, and Colony Collapse Disorder. Economic analyses indicate that honey bee rental markets have been able to adjust to those challenges, at least to date. Understanding future sustainability of rental markets requires greater knowledge of contributions of wild pollinators, of optimal management of pollination services from wild and managed organisms, and of the value of pollination services provided by wild and managed organisms.