Behavior Of Honey Bees Research Articles

Biotic and abiotic stresses on honeybee health.

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.

Hygienic behavioural response of honey bees (Apis mellifera and Apis cerana) against pin-killed brood as trait evaluation in Kashmir

In Apis mellifera and Apis cerana hygienic behavior involves recognition and removal of sick, damaged or dead brood from capped cells. We investigated whether bees react in the same way to grouped versus isolated damaged capped brood cells. Ten colonies of Apis mellifera honey bees and ten colonies of Apis cerana honey bees were used for this investigation. Capped worker brood cells aged 12 to 14 days old were perforated with the pin-killing method. After making holes in the brood cells, the combs were placed back into the hives; 24 h later the number of cleaned cells was recorded in areas with pin-killed and control brood cells. Four repetitions were made in each colony. Isolated cells were more frequently cleaned than grouped cells, though variance analysis showed no significant difference. Apis cerana bees also were somewhat, though not significantly more hygienic than Apis mellifera honey bees with mean removal of pin killed brood 97.46+/-1.37% and 83.83+/1.13% respectively. We conclude that honey bees can detect and remove both isolated and grouped dead brood. The tendency towards greater hygienic efficiency directed towards grouped Hygienic behaviour in honey bees was studied for first time with the aim of understanding mechanisms of pathogen resistance and colony health. It shows how honey bees confer colony level resistance and remove dead and diseased brood from the colony. This hygienic behavioural study can potentially increase the procedure of screening colonies for hygiene and breeding.

Examining parent-of-origin effects on transcription and RNA methylation in mediating aggressive behavior in honey bees (Apis mellifera)

Conflict between genes inherited from the mother (matrigenes) and the father (patrigenes) is predicted to arise during social interactions among offspring if these genes are not evenly distributed among offspring genotypes. This intragenomic conflict drives parent-specific transcription patterns in offspring resulting from parent-specific epigenetic modifications. Previous tests of the kinship theory of intragenomic conflict in honey bees (Apis mellifera) provided evidence in support of theoretical predictions for variation in worker reproduction, which is associated with extreme variation in morphology and behavior. However, more subtle behaviors – such as aggression – have not been extensively studied. Additionally, the canonical epigenetic mark (DNA methylation) associated with parent-specific transcription in plant and mammalian model species does not appear to play the same role as in honey bees, and thus the molecular mechanisms underlying intragenomic conflict in this species is an open area of investigation. Here, we examined the role of intragenomic conflict in shaping aggression in honey bee workers through a reciprocal cross design and Oxford Nanopore direct RNA sequencing. We attempted to probe the underlying regulatory basis of this conflict through analyses of parent-specific RNA m6A and alternative splicing patterns. We report evidence that intragenomic conflict occurs in the context of honey bee aggression, with increased paternal and maternal allele-biased transcription in aggressive compared to non-aggressive bees, and higher paternal allele-biased transcription overall. However, we found no evidence to suggest that RNA m6A or alternative splicing mediate intragenomic conflict in this species.

The ant’s weapon improves honey bee learning performance

Formic acid is the main component of the ant’s major weapon against enemies. Being mainly used as a chemical defense, the acid is also exploited for recruitment and trail marking. The repelling effect of the organic acid is used by some mammals and birds which rub themselves in the acid to eliminate ectoparasites. Beekeepers across the world rely on this effect to control the parasitic mite Varroa destructor. Varroa mites are considered the most destructive pest of honey bees worldwide and can lead to the loss of entire colonies. Formic acid is highly effective against Varroa mites but can also kill the honeybee queen and worker brood. Whether formic acid can also affect the behavior of honey bees is unknown. We here study the effect of formic acid on sucrose responsiveness and cognition of honey bees treated at different live stages in field-relevant doses. Both behaviors are essential for survival of the honey bee colony. Rather unexpectedly, formic acid clearly improved the learning performance of the bees in appetitive olfactory conditioning, while not affecting sucrose responsiveness. This exciting side effect of formic acid certainly deserves further detailed investigations.

Seed treatment with neonicotinoid insecticides does not affect the foraging behavior of honey bees

Seed treatment with neonicotinoid insecticides does not affect the foraging behavior of honey bees

Electromagnetic fields disrupt the pollination service by honeybees.

We assessed the effect that electromagnetic field (EMF) exerts on honeybees' pollination efficiency using field and laboratory experiments. First, we measured levels of gene and protein expression in metabolic pathways involved in stress and behavioral responses elicited by EMF. Second, we assessed the effect of EMF on honeybee behavior and seed production by the honeybee-pollinated California poppy and, lastly, by measuring the consequences of pollination failure on plants' community richness and abundance. EMF exposure exerted strong physiological stress on honeybees as shown by the enhanced expression of heat-shock proteins and genes involved in antioxidant activity and affected the expression levels of behavior-related genes. Moreover, California poppy individuals growing near EMF received fewer honeybee visits and produced fewer seeds than plants growing far from EMF. Last, we found a hump-shaped relationship between EMF and plant species richness and plant abundance. Our study provides conclusive evidence of detrimental impacts of EMF on honeybee's pollination behavior, leading to negative effects on plant community.

Chronic larval exposure to thiacloprid impairs honeybee antennal selectivity, learning and memory performances.

The use of agricultural neonicotinoid insecticides has sub-lethal chronic effects on bees that are more prevalent than acute toxicity. Among these insecticides, thiacloprid, a commonly used compound with low toxicity, has attracted significant attention due to its potential impact on the olfactory and learning abilities of honeybees. The effect of sub-lethal larval exposure to thiacloprid on the antennal activity of adult honeybees (Apis mellifera L.) is not yet fully understood. To address this knowledge gap, laboratory-based experiments were conducted in which honeybee larvae were administered thiacloprid (0.5mg/L and 1.0mg/L). Using electroantennography (EAG), the impacts of thiacloprid exposure on the antennal selectivity to common floral volatiles were evaluated. Additionally, the effects of sub-lethal exposure on odor-related learning and memory were also assessed. The results of this study reveal, for the first time, that sub-lethal larval exposure to thiacloprid decreased honeybee antenna EAG responses to floral scents, leading to increased olfactory selectivity in the high-dose (1.0mg/L) group compared to the control group (0mg/L vs. 1.0mg/L: p = 0.042). The results also suggest that thiacloprid negatively affected odor-associated paired learning acquisition, as well as medium-term (1h) (0mg/L vs. 1.0mg/L: p = 0.019) and long-term memory (24h) (0mg/L vs. 1.0mg/L: p = 0.037) in adult honeybees. EAG amplitudes were dramatically reduced following R-linalool paired olfactory training (0mg/L vs. 1.0mg/L: p = 0.001; 0mg/L vs. 0.5mg/L: p = 0.027), while antennal activities only differed significantly in the control between paired and unpaired groups. Our results indicated that exposure to sub-lethal concentrations of thiacloprid may affect olfactory perception and learning and memory behaviors in honeybees. These findings have important implications for the safe use of agrochemicals in the environment.

A combination of the frequent fungicides boscalid and dimoxystrobin with the neonicotinoid acetamiprid in field-realistic concentrations does not affect sucrose responsiveness and learning behavior of honeybees

The increasing loss of pollinators over the last decades has become more and more evident. Intensive use of plant protection products is one key factor contributing to this decline. Especially the mixture of different plant protection products can pose an increased risk for pollinators as synergistic effects may occur. In this study we investigated the effect of the fungicide Cantus® Gold (boscalid/dimoxystrobin), the neonicotinoid insecticide Mospilan® (acetamiprid) and their mixture on honeybees. Since both plant protection products are frequently applied sequentially to the same plants (e.g. oilseed rape), their combination is a realistic scenario for honeybees. We investigated the mortality, the sucrose responsiveness and the differential olfactory learning performance of honeybees under controlled conditions in the laboratory to reduce environmental noise. Intact sucrose responsiveness and learning performance are of pivotal importance for the survival of individual honeybees as well as for the functioning of the entire colony. Treatment with two sublethal and field relevant concentrations of each plant protection product did not lead to any significant effects on these behaviors but affected the mortality rate. However, our study cannot exclude possible negative sublethal effects of these substances in higher concentrations. In addition, the honeybee seems to be quite robust when it comes to effects of plant protection products, while wild bees might be more sensitive.

Temperament of Ethiopian honeybees

Information on the relative defensive behavior variations of Ethiopian bees and factors associated with temperament variation is not available. The objective of this study was to identify the temperament conditions of these honeybee populations. Two hundred forty farmer beekeepers from 57 localities were interviewed based on pre-structured questionnaire to determine aggressive behavior of Ethiopian honeybees, seasons and factors responsible for heightening their aggressiveness. The aggression rate of Ethiopian honeybee groups were determined for 3001 honeybee colonies and analyzed using Kruskal-wallis ANOVA. The aggressiveness varies among honeybee groups. Apis mellifera jemenitica honeybees are highly aggressive while Apis mellifera monticolla honeybees are relatively docile. The seasons of the year in which aggressiveness enhanced also vary both within and between honeybee groups depending on climatic conditions of their respective areas. The aggression generally heightens when nectar and pollen are abundantly available which is associated with honey flow and harvest and brooding periods. Attacks of enemies are also found the primary factor enhancing the aggression behavior across all honeybee groups. Aggression rate is significant and positively correlated with temperature and negatively with altitude. Generally lowland and southern region honeybees are more aggressive than highlands and northern region honeybees.

Metabolic profiling of Apis mellifera larvae treated with sublethal acetamiprid doses

Acetamiprid is a neonicotinoid insecticide used in crop protection worldwide. Such widespread application can pose risks to pollinator insects, particularly to honeybees (Apis mellifera); therefore, the evaluation of the harmful effects of acetamiprid is necessary. Recent studies report behavior and gene expression dysfunction in honeybees, related to acetamiprid contamination. However, most studies do not consider potential metabolism disorders. To examine the effects of sublethal acetamiprid doses on the hemolymph metabolism of honeybees, worker bee larvae(2 days old) were fed with sucrose water containing different concentrations of acetamiprid (0, 5, and 25 mg/L) until capped (6 days old). The hemolymph (200 μL) of freshly capped larvae was collected for liquid chromatography-mass spectrometry (LC-MS). Overall, increasing acetamiprid exposure induced greater metabolic variations in worker bee larvae(treated groups compared to untreated). In the positive ion mode, 36 common differential metabolites in the acetamiprid-treated groups were screened from the identified differential metabolites. Of these, 19 metabolites were upregulated, and 17 were downregulated. 10 common differential metabolites were screened in the negative ion mode. 3 metabolites were upregulated, and 7 metabolites were downregulated. These common metabolites included traumatic acid, indole etc. These commonly differentiated metabolites were classified as compounds with biological roles, lipids, and phytochemical compounds, and others. The metabolic pathways of common differentiated metabolites with significant differences (P < 0.05) included the metabolism of tryptophan, purines, phenylalanine, etc. As the concentration of acetamiprid increased, the content of traumatic acid increased, the content of tryptophan metabolite l-kynurenine and indole decreased, and the content of lipids also decreased. Our results revealed that the damage to honeybee larvae increased when the acetamiprid solution formulations residue in their food had a concentration higher than 5 mg/L, causing metabolic disorders in various substances in larvae. Analysis of these metabolic processes can provide a theoretical basis for further research on the metabolism of acetamiprid-treated honeybees and elucidate the detoxification mechanisms.

Effects of octopamine on memory retention under chemical stress: a behavioral study on honey bees

Honey bees may experience the adverse effects of environmental contaminants when exposed during foraging trips, or something to that effect. We hypothesized that octopamine (OA), with important functions in reward signaling and learning, can improve the behavior of honey bees under chemical stress. Memory retention and sucrose responsiveness were evaluated using the proboscis extension reflex (PER) assay. The one-day-old bees were exposed separately to diazinon, imidacloprid, paraquat, manganese, and thymol at concentrations of 0.22, 29.04, 55.69, 106.19, and 0.91 ppm, respectively. On the 21st day of exposure, the bees’ responses to memory retention and sucrose responsiveness experiments were recorded after the training trial. In addition, PERs were recorded after OA injection. During the intervals, honey bees were exposed to the toxins topically. The expression levels of OA receptor genes, AmoctαR1 and AmoctβR4, were measured. The sucrose responsiveness tests showed no significant differences between the bees stimulated with the control solutions or toxins. Moreover, our results indicated that memory retention significantly declined in honey bees exposed to toxins compared to the controls (P ≤ 0.05). According to the findings, OA improved the memory retention of honey bees exposed to toxins (P ≤ 0.05). The expression levels of AmoctαR1 and AmoctβR4 genes significantly increased in the treated honey bees, especially those exposed to paraquat and manganese, after 30 min post-OA injection. It can be concluded that under chemical stress, OA administration encouraged honey bees to respond to a stimulus. Therefore, it can be added to a nutrient-enriched diet.

Preliminary Evidence That Fiji Water Has Protective Effects against Aluminum Toxicity in Honey Bees (Apis mellifera).

Researchers have determined that bioavailable aluminum chloride (AlCl3) may affect honey bee behavior (e.g., foraging patterns and locomotion) and physiology (e.g., abdominal spasms). The purpose of these experiments was to determine if Fiji water reduces the impacts of AlCl3 toxicity in bees by measuring circadian rhythmicity (number of times bees crossed the centerline during the day and night), average daily activity (average number of times bees crossed the centerline per day), and mortality rates (average number of days survived) using an automated monitor apparatus. Overall, the AlCl3 before and after Fiji groups had significantly higher average daily activity and rhythmicity rates compared to their respective AlCl3 before and after deionized water (DI) groups. One of the AlCl3 before DI groups exhibited no difference in rhythmicity rates compared to its respective AlCl3 after Fiji group. Overall, these results suggest that Fiji water might exert protective effects against AlCl3. The AlCl3 groups paired with Fiji water had higher activity and rhythmicity levels compared to the AlCl3 groups paired with DI. It is important for researchers to continue to study aluminum and possible preventatives for aluminum uptake.

Optimizing the Parameters of Long Short-Term Memory Networks Using the Bees Algorithm

Improving the performance of Deep Learning (DL) algorithms is a challenging problem. However, DL is applied to different types of Deep Neural Networks, and Long Short-Term Memory (LSTM) is one of them that deals with time series or sequential data. This paper attempts to overcome this problem by optimizing LSTM parameters using the Bees Algorithm (BA), which is a nature-inspired algorithm that mimics the foraging behavior of honey bees. In particular, it was used to optimize the adjustment factors of the learning rate in the forget, input, and output gates, in addition to cell candidate, in both forward and backward sides. Furthermore, the BA was used to optimize the learning rate factor in the fully connected layer. In this study, artificial porosity images were used for testing the algorithms; since the input data were images, a Convolutional Neural Network (CNN) was added in order to extract the features in the images to feed into the LSTM for predicting the percentage of porosity in the sequential layers of artificial porosity images that mimic real CT scan images of products manufactured by the Selective Laser Melting (SLM) process. Applying a Convolutional Neural Network Long Short-Term Memory (CNN-LSTM) yielded a porosity prediction accuracy of 93.17%. Although using Bayesian Optimization (BO) to optimize the LSTM parameters mentioned previously did not improve the performance of the LSTM, as the prediction accuracy was 93%, adding the BA to optimize the same LSTM parameters did improve its performance in predicting the porosity, with an accuracy of 95.17% where a hybrid Bees Algorithm Convolutional Neural Network Long Short-Term Memory (BA-CNN-LSTM) was used. Furthermore, the hybrid BA-CNN-LSTM algorithm was capable of dealing with classification problems as well. This was shown by applying it to Electrocardiogram (ECG) benchmark images, which improved the test set classification accuracy, which was 92.50% for the CNN-LSTM algorithm and 95% for both the BO-CNN-LSTM and BA-CNN-LSTM algorithms. In addition, the turbofan engine degradation simulation numerical dataset was used to predict the Remaining Useful Life (RUL) of the engines using the LSTM network. A CNN was not needed in this case, as there was no feature extraction for the images. However, adding the BA to optimize the LSTM parameters improved the prediction accuracy in the testing set for the LSTM and BO-LSTM, which increased from 74% to 77% for the hybrid BA-LSTM algorithm.

Surveillance for Avocado Sunblotch Viroid Utilizing the European Honey Bee (Apis mellifera).

Avocado is one of the world's fastest growing tropical fruit industries, and the pathogen avocado sunblotch viroid (ASBVd) is a major threat to both production and access to international export markets. ASBVd is seed transmissible, with infection possible via either the male (pollen) or female gametes. Surveillance for ASBVd across commercial orchards is a major logistical task, particularly when aiming to meet the stringent standards of evidence required for a declaration of pest freedom. As with many fruit crops, insect pollination is important for high avocado yields, and honey bee (Apis mellifera) hives are typically moved into orchards for paid pollination services. Exploiting the foraging behavior of honey bees can provide a complementary strategy to traditional surveillance methods. High-throughput sequencing (HTS) of bee samples for plant viruses shows promise, but this surveillance method has not yet been tested for viroids or in a targeted plant biosecurity context. Here, we tested samples of bees and pollen collected from pollination hives in two ASBVd orchard locations, one in Australia, where only four trees in a block were known to be infected, and a second in South Africa, where the estimated incidence of infection was 10%. Using real-time RT-PCR and HTS (total RNA-seq and small RNA-seq), we demonstrated that ASBVd can be confidently detected in bees and pollen samples from hives within 100 m of infected trees. The potential for using this approach in ASBVd surveillance for improved orchard management and supporting market access is discussed.

Morphometric characteristics of Ukrainian steppe bees depending on the method of controlled queen mating

Bee breed is an important factor in determining bee family development and productivity, as it affects honey production, disease resistance, climate adaptation, and bee behaviour characteristics. The purpose of the study was to establish the relationship between the methods of mating queens and the morphological characteristics of bees of the Ukrainian steppe breed and the productive indicators of bee colonies. To conduct the research, 43 bee colonies with queen sisters of the Ukrainian steppe breed mated by different methods of natural mating were established in the Vinnytsia oblast. According to the results of mating, there were 22 queen bees in the control group, and 21 queen bees in the experimental group. The queens of the first control group mated in a normal natural way without any restrictions. The queen bees of the experimental group mated under time and space control. Based on the results of the research, the relationship between the integrity of the colony and its morphological features and productive indicators was established. Thus, experimental families have different degrees of belonging to the Ukrainian steppe breed, control – 59% and experimental – 87.2% (p &lt; 0.001). According to the cubital index, the advantage was 8.2% (p &lt; 0.001) in favour of the experimental group. The best family integrity on the hantel index was observed in families in which queens were mated in a controlled time and space, with a difference of 3.32% (p &lt; 0.001). In the control group, where uncontrolled mating of queens was performed, more bees were found for discoid displacement with an excess of the standard indicator for the breed. Families in the experimental group were stronger by 14.5% (p &lt; 0.001) compared to the control group. They provided 41.9% more honey, built 22.1% more honeycombs (p &lt; 0.01), and the need for Kandy feeding was 31.8% less (p &lt; 0.001). In addition, the bees of the experimental group had pronounced hygienic behaviour and required less labour costs. The practical significance of the study lies in the possibility of establishing patterns of action of factors on a particular breed and confirms the need to implement breeding programmes in beekeeping

Western honey bee (Apis mellifera L.) attraction to commercial pollen substitutes and wildflower pollen in vitro

AbstractMany beekeepers feed their western honey bee (Apis mellifera) colonies artificial pollen substitutes to provide colonies with adequate nutrition during times of limited pollen quantity or quality. We provided caged worker bees commercially available pollen substitutes (AP23, MegaBee, UltraBee) and wildflower pollen in a choice‐test to determine their relative attraction to/preference for the diets. We measured diet consumption by honey bees and observed honey bee behaviour to evaluate bee preferences for certain diets. The bees interacted with and consumed more wildflower pollen than they did any of the commercially available pollen substitutes. Our data suggest that bees have a strong preference for wildflower pollen over commercially available pollen substitutes.

Circular RNA ame_circ_2015 Function as microRNA Sponges in Regulating Egg-Laying of Honeybees (Apis mellifera).

Honeybees (Apis mellifera) are critical to maintaining ecological balance and are important pollinators. The oviposition behavior in honeybees is important and complex. Circular RNAs (circRNAs) are found to form circRNA-miRNA crosstalk and play important roles in reproduction processes. Here, dual luciferase reporter was used to confirm the crosstalk between ame_circ_2015 and ame_miR-14-3p. Functional experiments in vitro and in vivo were performed to investigate the biological functions of ame_circ_2015 in egg-laying of queens. The results showed that ame_circ_2015 directly target ame_miR-14-3p, and the expression of ame_circ_2015 was negatively correlated with ame_miR-14-3p expression. Overexpression results showed that ame_circ_2015 promoted the number of eggs laid and knockdown of ame_circ_2015 suppressed the number of eggs laid. It demonstrates that up-regulated ame_circ_2015 promotes the number of eggs laid by sponging ame_miR-14-3p. The study will provide information towards a better understanding of circRNA-miRNA crosstalk in egg-laying in honeybees.

Honey bees reared in isolation adhere to normal age-related division of labor when reintroduced into a colony

Early social experiences during developmental life stages have been demonstrated to influence adult behavior in vertebrates and invertebrates. However, cooperative behaviors observed in social insects are often regarded as simple instinctual responses to positive and negative feedback. Here we test if rearing environment influences the resulting adult bee’s somewhat predictable progression through a series of age-related tasks (temporal polyethism). Honey bee larvae were reared either in their parental colony, or artificially in the laboratory. Newly emerged adults were individually identified and introduced into a single observation hive where their behavior was observed three times a day for 28 days. In vitro-reared bees were observed engaging in every behavior in which colony-reared bees engaged including: attending the queen, manipulating wax comb, defending the hive entrance, and foraging. Moreover, in vitro-reared bees appeared to be responding appropriately to colony-level cues that coordinate task allocation within age-related polyethism. However, in vitro-reared bees did suffer detectably reduced lifespans. Further research, potentially incorporating methods such as establishing colonies composed exclusively of in vitro-reared bees, would offer additional insight into the plasticity of honey bee behaviors.

A Method for Feature Subset Selection in Software Product Lines

Software product line (SPL) represents methods, tools, and techniques for creating a group of related software systems. Each product is a combination of multiple features. So, the task of production can be mapped to a feature subset selection problem, which is an NP-hard problem. This issue is very significant when the number of features in a software product line is huge. This chapter is aimed to address the feature subset selection in software product lines. Furthermore, the authors aim at studying the performance of a proposed multi-objective method in solving this NP-hard problem. Here, a multi-objective method (MOBAFS) is presented for feature selection in SPLs. The MOBAFS is a an optimization algorithm, which is inspired by the foraging behavior of honeybees. This technique is evaluated on five large-scale real-world software product lines in the range of 1,244 to 6,888 features. The proposed method is compared with the SATIBEA. According to the results of three solution quality indicators and two diversity metrics, the proposed method, in most cases, surpasses the other algorithm.

Evaluating the Influence of Agro-Environmental Measures on Honey Bees Based on Genetic Pollen Analysis With Nanopore Sequencing

Intensive land use is one of the main drivers contributing to the loss of pollinating insects due to the distribution of pesticides and the reduction of flower diversity. This work analyzes honey bee pollen samples taken from areas of different agricultural intensity. The aim is to classify the plant species contained in the pollen samples using DNA barcodes and nanopore sequencing in order to evaluate the influence of different agro-environmental measures on the foraging behavior of honey bees. First results concern the DNA extraction and the identification of universal primer sequences in preparation for sequencing with the MinION Mk1c from Oxford Nanopore Technologies.