Bee Apis Mellifera Research Articles

EVALUATION OF THE QUALITY OF BEE HONEY (Apis mellifera) FROM CENTRAL-SOUTH REGION OF TAMAULIPAS, MEXICO

Objective: The objective of this study was to evaluate different quality criteria of Apis mellifera bee honey from the municipality of Llera in the central-southern region of the state of Tamaulipas, Mexico. Theoretical Framework: In the state of Tamaulipas, A. mellifera honey is produced, considered one of the most important beekeeping products. This activity reflects the economic strengthening and well-being of this area and it is fundamental for ecosystem’s survival and biodiversity. Method: The methodology applied for this study focused on the selection of six samples from different apiaries in the municipality of Llera, using standardized techniques for the corresponding analyses. Results and Discussion: Results showed that most of the honeys meet quality standards. Values ​​were expressed as mean values ​​± SD. Data were subjected to an analysis of variance and Tukey’s test, and statistical significance was established at p≤0.05. Research Implications: The sampling of honey was limited by the availability of beekeepers; on the other hand, some honey crystallized in less time than others. Originality/Value: The study allowed us to evaluate the quality of honey, which guarantees having a high-quality product for marketing.

Visual discrimination learning in the Australian stingless bee Tetragonula carbonaria (Hymenoptera: Apidae)

AbstractKarl von Frisch's ground‐breaking research first demonstrated visual learning in the European honey bee (Apis mellifera). The study of Australian native bees and their cognitive abilities, however, is still a relatively new and emerging field. Here we examined visual cognition in the Australian stingless bee, Tetragonula carbonaria. First we tested for any colour preferences in T. carbonaria. Then we set stingless bees with three simple visual discrimination learning tasks using distinct colours (blue or yellow), oriented gratings (horizontal or vertical) and patterns (radial or concentric). In the colour preference task, we found evidence of a weak colour preference, with bees preferring colours blue and purple. In the visual discrimination task, T. carbonaria learned all three tasks in just 10 training trials. Bees learned equally well across the colour, orientation and pattern conditions, suggesting rapid visual learning. Future research should focus on closing knowledge gaps in Australian native bee cognition research, building upon the results of this study and exploring more complex non‐elemental learning.

Investigating the Phylogenetic Relationships of the Iranian Honey Bee with Other Bee Breeds Worldwide Using the Cytochrome Oxidase I Region

Background: Honey bees, classified within the insect class and widely distributed globally, consist of 26 identified subspecies across five evolutionary lines. Among these, the Iranian honey bee (Apis mellifera meda) is notable for its presence in Iran and neighboring regions. This subspecies exhibits unique biological traits, including a high reproductive capacity and effective propolis collection, distinguishing it from other local bee populations. Understanding genetic diversity within these populations is crucial for conservation and breeding efforts. Objectives: The aim of this study is to determine the phylogenetic relationships and natural variations of the Iranian honey bee in comparison to other bee breeds worldwide using the cytochrome oxidase I (COI) region. Methods: The study focuses on the identification of COI gene sequences in honeybees. The mitochondrial COI gene sequences related to the Iranian honey bee and eight populations of other honey bee breeds from around the world (24 ecotypes) were extracted and aligned from the genome database (NCBI). BLAST was used for sequence retrieval, and Clustal W was employed for alignment among species. Phylogenetic analysis was performed using MEGA software, applying the Neighbor Joining method to construct a phylogenetic tree based on the edited sequences. The percentage of nucleotide substitutions and replacements was calculated using the maximum likelihood method. Additionally, molecular diversity indices were computed using DnaSP software to assess genetic variation and conservation parameters among populations. Results: The bioinformatics analysis of biological data revealed that transfer substitution occurred more frequently than crossover substitution. Additionally, the percentage of substitution in pyrimidine bases was higher than in purine bases. The dN/dS substitution ratio in the gene locus sequence across the examined ecotypes was estimated at 0.08, indicating purifying selection during the evolution of this gene locus. Furthermore, examination of the COI region of the mitochondrial genome identified a total of 4 haplotypes, 20 mutations, and 195 polymorphic loci within the entire studied population. The neutrality values, based on Tajima's test, indicated effects related to genetic drift, genetic bottlenecks, or balancing selection during the evolutionary history of the studied population. Phylogenetic analysis revealed nine distinct categories of evolutionary paths for the COI gene in the studied ecotypes. In the phylogenetic tree, the Iranian honey bee was placed in a separate cluster, exhibiting the highest and lowest phylogenetic distances relative to Apis koschevnikovi and Apis mellifera, respectively. Conclusions: This research indicates that the conserved region of the mitochondrial cytochrome oxidase gene among various bee species is minimal, highlighting significant polymorphism and susceptibility to mutations. A total of 20 mutations and 195 polymorphic sites were identified, suggesting purifying selection processes that contribute to the gene's biological functions. The study also demonstrates that the COI region can effectively differentiate Iranian honey bee populations from others globally. Overall, these findings enhance our understanding of genetic diversity and evolutionary relationships within bee species, underscoring the importance of continued research for conservation efforts.

Inferring Long-Term and Short-Term Determinants of Genetic Diversity in Honey Bees: Beekeeping Impact and Conservation Strategies.

Bees are vital pollinators in natural and agricultural landscapes around the globe, playing a key role in maintaining flowering plant biodiversity and ensuring food security. Among the honey bee species, the Western honey bee (Apis mellifera) is particularly significant, not only for its extensive crop pollination services but also for producing economically valuable products such as honey. Here, we analyzed whole-genome sequence data from four Apis species to explore how honey bee evolution has shaped current diversity patterns. Using Approximate Bayesian Computation, we first reconstructed the demographic history of A. mellifera in Europe, finding support for postglacial secondary contacts, therefore predating human-mediated transfers linked to modern beekeeping. However, our analysis of recent demographic changes reveals significant bottlenecks due to beekeeping practices, which have notably affected genetic diversity. Black honey bee populations from conservatories, particularly those on islands, exhibit considerable genetic loss, highlighting the need to evaluate the long-term effectiveness of current conservation strategies. Additionally, we observed a high degree of conservation in the genomic landscapes of nucleotide diversity across the four species, despite a divergence gradient spanning over 15 million years, consistent with a long-term conservation of the recombination landscapes. Taken together, our results provide the most comprehensive assessment of diversity patterns in honey bees to date and offer insights into the optimal management of resources to ensure the long-term persistence of honey bees and their invaluable pollination services.

A Honey Bee In-and-Out Counting Method Based on Multiple Object Tracking Algorithm

The honey bee (Apis mellifera) is of great significance to both the ecological environment and human society, providing bee products and making a significant contribution to the pollination of crops [...]

Mechanistic exploration of royal jelly production in caged honey bees (Apis mellifera)

This study investigates the impact of bee pollen nutrition on the royal jelly production of honey bees (Apis mellifera). Results demonstrate that pollen diet significantly impacts hypopharyngeal gland (HPG) development and the expression of genes associated with royal jelly biosynthesis. Bees fed Brassica napus pollen exhibited superior HPG development, and increased mrjp1 expression (encoding a key royal jelly protein). While the cyp450 6AS8 gene expression (encoding a key enzyme in 10-HDA biosynthesis) was increased by pollen consumption, no distinct expression patterns were observed among the different pollen types tested. An in vitro bee cage platform for royal jelly production has been established to further understand the mechanisms behind royal jelly production in bees. The experiment demonstrated a positive correlation between the number of worker bees and the total yield of royal jelly per cage. However, when the number of worker bees is low, the amount of royal jelly each individual worker bee needs to produce increases. In conclusion, these findings enhance our understanding of the role of bee pollen nutrition in royal jelly production. Furthermore, the results from this in vitro bee cage platform suggest that the number of worker bees is a critical factor in royal jelly production, and that bees may possess a controllable mechanism for regulating royal jelly secretion.

Honey Bee Survival and Flight Capacity After Exposure to Sulfoxaflor Residues

Knowing the toxicity of insecticides used for pest control in melon on the bee Apis mellifera is essential for the conservation of this species in production areas, thus enabling the conciliation of insecticide applications with the sustainable use of pollinators in the field. From this perspective, this study aimed to evaluate the survival and flight ability of A. mellifera after exposure to residues of the insecticide Sulfoxaflor on melon leaves. The bioassay was conducted under laboratory conditions, in a completely randomized design set up in a 3 x 6 factorial arrangement, represented by two doses of the insecticide Sulfoxaflor (0.048 and 0.192 g i.a./L), one control (distilled water), and six exposure times after application of the product on melon leaves: immediately after spraying and 1h, 2h, 3h, 24h, and 48h after spraying. The insecticide Sulfoxaflor caused 100% morality in the bees exposed to the dose of 0.048 g i.a./L in the periods immediately after spraying and 1h, 2h, and 3h after spraying. The dose of 0.192 g i.a./L, regardless of the exposure time after spraying, resulted in 100% mortality. The median lethal time (TL50) provided by the Sulfoxaflor doses were significantly lower compared to the control, regardless of the time after foliar spraying. Sulfoxaflor negatively affected the flight ability of surviving bees. Regardless of the dose and exposure time after spraying, Sulfoxaflor was highly toxic via residues to A. mellifera under laboratory conditions.

In-depth Chemistry and Pharmacological Potential of Propolis: A Critical Review of Recent Developments

Background: One of the most popular beekeeping products is propolis. The word "propolis," which alludes to a beehive, has Greek sources and implies "defense for the community." Propolis is a resinous material that honey worker bees (Apis mellifera L.) and other bee species make for a variety of uses. Since 300 BC, propolis has been used as a traditional remedy. Various pharmacological effects of distinct propolis extracts as well as those of its ingredients, including antioxidant, antiulcer, anticancer, antiviral, anti-microbial, anti-inflammatory, and antifungal characteristics, have recently been identified. Objective: In this review article, we focus on the origin, recent advances in the chemical constituents, and new therapeutic potential of propolis. Material and Methods: An exhaustive analysis of the literature search was conducted. The standard keywords "propolis," "origin," "chemical constituents," "pharmacological activity," "recent advances," and "traditional uses" have been used to search a variety of the standard databases, such as Scopus and Elsevier, PubMed, ScienceDirect, and Science Web, for research and review articles published between 1998 and 2023. Results: This review article included over 150 articles (research and reviews) that were appraised and researched. Conclusion: Since 2012, more than 300 substances have been shown to have pharmacological action against a variety of illnesses, including cancer, inflammation, ulcers, wound healing, diabetes, bacterial, viral, and fungal infections, hepatic disorders, dental problems, brain diseases, etc. Overall, propolis may be considered a source of bioactive compounds for pharmaceutical development. Future studies should consider plant types, regional conditions, bee subspecies, and variations.

Stressdrives premature hive exiting behavior that leads to death in young honey bee (Apis mellifera) workers.

The Western honey bee, Apis mellifera, is an economically important pollinator, as well as a tractable species for studying the behavioral intricacies of eusociality. Honey bees are currently being challenged by multiple biotic and environmental stressors, many of which act concomitantly to affect colony health and productivity. For instance, developmental stress can lead workers to become precocious foragers and to leave the hive prematurely. Precocious foragers have decreased flight time and lower foraging efficiency, which can ultimately lower colony productivity and even lead to colony collapse. In this study, we tested the hypothesis that stress during pupal development can cause young workers to exit the hive prematurely before they are physically able to fly. This premature exiting behavior results in death outside the hive soon thereafter. To determine how various stressors may lead bees to perform this behavior, we subjected workers during the last pupal stage to either cold stress (26°C for 24h), heat stress (39°C for 24h), or Varroa destructor mite parasitization, and compared the rate of premature hive exits between stressed bees and their respective control counterparts. Upon emergence, we individually tagged focal bees in all treatment groups and introduced them to a common observation hive. We then followed tagged bees over time and monitored their survivorship, as well as their likelihood of performing the premature hive exiting behavior. We also dissected the hypopharyngeal glands of all treatment and control bees sampled. We found that significantly more bees in all three treatment groups exited the hive prematurely compared to their control counterparts. Bees in all treatment groups also had significantly smaller hypopharyngeal glands than control bees. Our results suggest that premature hive exiting behavior is driven by stress and is potentially a form of accelerated age polyethism that leads to premature death.

Pollinator functional group abundance and floral heterogeneity in an agroecological context affect mating patterns in a self-incompatible wild plant.

Restoration of seminatural field margins can elevate pollinator activity. However, how they support wild plant gene flow through interactions between pollinators and spatiotemporal gradients in floral resources remains largely unknown. Using a farm-scale experiment, we tested how mating outcomes (expected heterozygosity and paternity correlation) of the wild, self-incompatible plant Cyanus segetum transplanted into field margins (sown wildflower or grass-legume strips) were affected by the abundance of different pollinator functional groups (defined by species traits). We also investigated how the maternal plant attractiveness, conspecific pollen donor density, and heterospecific floral richness and density interacted with pollinator functional group abundance to modulate C. segetum mating outcomes. Multiple paternity increased (=lower paternity correlation) with greater local abundance of hoverflies (syrphids) and female medium-sized wild bees (albeit the latter's effect diminished with decreasing maternal plant attractiveness), and the presence of male bumblebees (Bombus) under low local floral richness. Cyanus segetum progeny genetic diversity increased with male Bombus presence but decreased with greater abundance of syrphids and honey bees (Apis mellifera). Overall, field margins supported plant-pollinator interactions ensuring multiple paternity and conservation of allelic diversity in C. segetum progeny. The contribution to plant mating outcomes of different pollinator functional groups was dictated by their local abundance or traits affecting pollen transfer efficiency. The local floral richness or maternal plant attractiveness sometimes modulated these relationships. This complex response of wild plant mating patterns to community interactions has implications for the use of field margins to restore functional pollination systems in farmed landscapes.

Survival and Flight Capacity of Apis mellifera after Contact with Residues of Spiromesifen on Melon Leaves

Balancing the application of insecticides with the preservation of bees in agricultural areas poses a significant challenge to farmers. Therefore, this study aims to assess the survival and flight capacity of Apis mellifera (L.) bees after contact with residues of the insecticide/acaricide Spiromesifen on melon leaves. The experiment occurred under laboratory conditions, in a completely randomized design and a 4x3 factorial scheme, with two doses of Spiromesifen (0.24 and 0.288 g a.i./L), a positive control (Thiamethoxam), and an absolute control (distilled water), at three exposure times: 1, 2, and 3 hours after treatment application. Spiromesifen caused mortality of 15.33% and 13.80% after 1 hour of spraying, 20.05% and 17.72% after 2 hours of spraying, and 21.52% and 14.33% after 3 hours of spraying, for lower and higher doses, respectively. Spiromesifen provided a median lethal time of 112.9 hours, regardless of dose and exposure time. After exposure to the lower dose of Spiromesifen at 1, 2, and 3 hours after spraying, 28.41%, 8.0%, and 17.0% of the bees were able to fly, respectively, while at the higher dose, 33.55% and 8.11% were able to fly after 1 and 2 hours of spraying. Bees exposed after 3 hours of spraying at the higher dose showed a flight activity similar to the absolute control. Contact with Spiromesifen residues on melon leaves was slightly lethal to the honey bee A. mellifera, but it reduced the flight capacity of surviving bees after exposure.

Comparative Assessment of the Allergenicity of Hyaluronidases from Polistes dominula (Pol d 2), Vespula vulgaris (Ves v 2), and Apis mellifera Venom (Api m 2).

Sensitization to cross-reactive allergens complicates identifying the culprit insect in Hymenoptera venom allergy via diagnostic tests. This study evaluates sensitization to hyaluronidases (Api m 2 from honey bee (Apis mellifera) venom, HBV; Pol d 2 from European paper wasp (Polistes dominula) venom, PDV; and Ves v 2.0101 and Ves v 2.0201 from yellow jacket (Vespula vulgaris) venom, YJV) and their cross-reactivity in allergic patients from Italy, Spain, and Germany using ImmunoCAPs, ELISA, and basophil activation tests. Sensitization rates were 45% for Api m 2 in HBV-allergic subjects, 25% for Pol d 2 in PDV-allergic individuals, and 20% and 10% for Ves v 2.0201 and Ves v 2.0101 in YJV-allergic patients, respectively. Patients primarily sensitized to Api m 2 showed minimal cross-reactivity to vespid hyaluronidases, whereas those primarily sensitized to Pol d 2 or Ves v 2.0201 exhibited IgE reactivity to Api m 2. Neither Pol d 2 nor Ves v 2.0201 triggered basophil activation. Cross-reactivity of Api m 2, Pol d 2, and Ves v 2.0201 depends on the primary sensitizing venom. Sensitization to Pol d 2 and Ves v 2.0201 remains below 25%, yet these patients may exhibit cross-reactivity to Api m 2. Conversely, HBV-allergic patients sensitized to Api m 2 show minimal reactivity to Pol d 2 or Ves v 2.0201.

Bee bread collected by honey bees (Apis mellifera) as a terrestrial pesticide biomarker to complement water studies.

Pesticides in aquatic environments are frequently studied, yet those in terrestrial environments remain relatively unexplored. This study monitored bee bread collected from two apiaries located in a typical agricultural environment in Switzerland from March to August 2022 as a proxy for terrestrial pesticide inputs. The temporal appearance of the selected pesticides was compared to their profiles in the water of a small catchment within this area. Overall, 62% (31 of 50) of the targeted pesticides were detected in bee bread, with occurrences in both apiaries largely overlapping (23 pesticides), demonstrating a similar agricultural landscape across the region. Furthermore, nine pesticides were detected in bee bread and water, two pesticides were detected only in bee bread, and two additional pesticides were detected only in water. Comparative temporal analysis revealed that pesticides with moderate-to-high movement potential [Groundwater ubiquity score (GUS) ≥ 2.19] appeared simultaneously in bee bread and water (azoxystrobin, boscalid, flufenacet and terbuthylazine). However, pesticides with low movement potential (GUS ≤ 1.86) showed different profiles in both matrices (cyprodinil, prosulfocarb, tebuconazole and thiacloprid), indicating the difficulty of predicting their fate, given that they adhere to soil particles and cannot be covered by current water monitoring programmes. Our findings present bee bread as a viable biomarker for monitoring pesticides by complementing the conventional water monitoring, and permitting a more comprehensive assessment of the exposure of terrestrial organisms to pesticides. Bee bread allows immediate recording of the applied pesticides and promptly reflects the seasonal variation in pesticide use. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Occurrence and distribution of the microsporidium Vairimorpha (Nosema) spp. in apiaries in Brazil - Systematic review

Nosemosis is one of the main diseases of bees, caused by microsporidia of the genus Vairimorpha (Nosema). The main etiologic agents are Vairimorpha apis and Vairimorpha ceranae. These pathogens are widely distributed around the world, and in Brazil, they have already been reported in some states, but these data have never been gathered in a review. The objective of this study was to perform a systematic review of the occurrence and distribution of the microsporidium Vairimorpha spp. in apiaries in Brazil. The search was done in the SciELO, PubMed, DOAJ, and Capes Journals (Scopus) databases. 14 articles were selected and published in English and Portuguese. In the included publications, only eight Brazilian states were referred (Bahia, Espírito Santo, Goiás, Minas Gerais, Piauí, Rio Grande do Sul, Santa Catarina, and São Paulo). No work was conducted in the northern of the country, and most of the publications are concentrated in the southern and southeastern. Regarding the Vairimorpha species, only V. apis and V. ceranae were investigated, and V. ceranae was predominantly detected. Most of the studies were done only with the Africanized bee Apis mellifera. This review showed which Brazilian regions have never been explored in terms of incidence and distribution of these pathogens, revealing a gap to be filled by the country's beekeeping surveillance and health systems. In addition, because of the great Brazilian biodiversity, it is evident that the occurrence and distribution of these pathogens also need to be investigated with other bee species.

A Comparative Assessment of Three Pollen Substitutes for Honey Bee (Apis Mellifera L.) During Winter and Spring

A Comparative Assessment of Three Pollen Substitutes for Honey Bee (Apis Mellifera L.) During Winter and Spring

Water Deprivation and Sowing Times Alter Plant-Pollination Interactions and Seed Yield in Sunflower, Helianthus annuus L. (Asteraceae).

Climate change effects, including temperature extremes and water stress, cause abiotic stress in plants. These changes directly affect flowering and the flower reward system for pollinators, influencing plant-pollinator interactions and ultimately seed production in flowering plants. Here, we tested the effects of water deprivation on the behavior of various pollinator species, plant-pollinator interactions, and the seed yield of sunflower, Helianthus annuus L. (Asteraceae). Sunflower was sown during four different months (January-April) and subjected to two different water availability levels (well-watered and water-deprived). Pollinator abundance was recorded five times a day (8:00 am, 10:00 am, 12:00 pm, 2:00 pm, and 4:00 pm) from flower heads and the florets. In addition, foraging behavior was also recorded. We found that lowest abundance, visit duration, and visitation rate occurred in April-sown sunflower. The European honey bee Apis mellifera L. (Hymenoptera: Apidae) was the most abundant visitor to sunflower, the hover fly Eristalinus aeneus (Diptera: Syrphidae) exhibited the longest visit duration, while Xylocopa sp. (Hymenoptera: Apidae) exhibited the highest visitation rate. The visitation rate of bees was significantly affected by water stress, with more bee visits occurring under well-watered conditions. Additionally, plant parameters, including flower head diameter, head weight, seed number, and seed weight, were significantly lower in the water-deprived treatments in April-sown sunflower. Open flowers without the pollination exclusion cages showed a higher yield, indicating the pollination dependence of sunflower. In conclusion, the plant modifications induced by sowing months and water-deprived conditions may alter pollinator behavior and may ultimately affect sunflower yield.

An amitraz-based miticide does not appear to affect the bacterial microbiota of Apis mellifera (Apidae: Hymenoptera, Linnaeus, 1758) or Varroa destructor (Acari: Varroidae, Anderson & Trueman, 2000)

ABSTRACT The use of pesticides in beehives constitutes an important health issue for honey bees (Apis mellifera). Miticide treatments are not lethal to bees but could still impose significant sublethal costs. This study examined the impacts of amitraz, a commonly used miticide, on the bacterial communities of the honey bee gut and Varroa destructor mites. We sequenced and compared gut 16S rDNA composition pre – and post-amitraz treatment. Amitraz did not significantly influence bacterial gut communities in either honey bees or mites during the first six weeks following treatment. The gut bacterial community of bees was mainly dominated by the commonly observed microbiota in bees, which included species in the genera Gilliamella, Snodgrassella, and Frischella. Deformed wing virus (DWV) loads were analysed but were also unaffected by amitraz treatment over the six-week period studied. The bacterial community of Varroa destructor mites was heavily dominated by Bartonella spp., in contrast to results observed elsewhere. Our results indicating that amitraz does not appear to affect honey bee microbiota should be helpful for beekeepers who rely on this pesticide for mite control.

Exposure to constant artificial light alters honey bee sleep rhythms and disrupts sleep

Artificial light at night (ALAN) changes animal behavior in multiple invertebrates and vertebrates and can result in decreased fitness. However, ALAN effects have not been studied in European honey bees (Apis mellifera), an important pollinator in which foragers show strong circadian rhythmicity. Colonies can be exposed to ALAN in swarm clusters, when bees cluster outside the nest on hot days and evenings, and, in limited cases, when they build nests in the open. We captured and maintained foragers in incubated cages and subjected them to constant light (LL), constant dark (DD), or 12 h light:12 h dark (LD) cycle, and observed them with infrared cameras. After 79 h, there was a significant interaction of treatment and time because LL bees slept less. In detail, the bees maintained a regular sleep pattern for three days but LL bees showed a shift on the fourth day. LL bees had the largest sleep differences from LD controls, with trends of lengthened periods and increased phase misalignment from both LD and DD bees. LL bees also experienced significantly more disturbances from their nestmates and preferred to sleep in the lower portion of the cages, which had significantly lower light intensity. These findings suggest that ALAN can disrupt the sleep of honey bee foragers, which has implications for their behavior and overall colony health.

Glyphosate contact alters the expression of genes in the head of africanized Apis mellifera bees

The increase in the world population results in a greater demand for food, intensifying the dependence on pesticides use. Glyphosate, a pesticide widely used in crops, can contaminate resources collected by bees. In this context, this study aimed to analyze the transcriptome of the head of Africanized Apis mellifera bees during the foraging phase to determine whether contact with the herbicide glyphosate, in lethal and sublethal doses, causes changes in the gene expression profile. For this, 180 marked bees were collected from their hives, aged 21 days, and distributed into three treatment groups: 1) bees in contact with the lethal dose of glyphosate (255.73 µg/bee); 2) bees in contact with the sublethal dose of glyphosate (2.5573 µg/bee); 3) control group with distilled water. Transcriptome analysis was performed on 12 bees from each treatment after one and four hours of exposure. The results show that one hour of contact with glyphosate resulted in 57 genes presenting differential expression in relation to the control (11 lethal and 53 sublethal), interfering in the signaling, communication and metabolism processes, while four hours of exposure, 38 genes (32 lethal and 11 sublethal) related, mainly, to the stimulation of the immune response. In summary, glyphosate affects the gene expression of honey bees during the foraging phase, at both doses, resulting in negative effects on behavior, metabolism and immune system, which compromises the health, activity and development of the colonies, also compromising the process of pollination.

Lactic acid treatment on infested honey bees works through a local way of action against Varroa destructor

Lactic acid is an alternative treatment to hard chemicals against Varroa destructor, the parasitic mite of the Western honey bee Apis mellifera. This soft acaricide is used only for small apiaries due to its laborious administration. However, the mode of action of this honey bee medication remains unknown. Previous studies showed that a direct contact between the arolia of V. destructor and lactic acid altered their morphology and led to an impairment of grip. Yet, there is no evidence for the way of action of lactic acid in a realistic in-hive scenario, i.e. after an indirect exposure of the mite through honey bees. We investigated the nature of lactic acid activity in the hive treatment context. The local and/or systemic way of action of this honey bee treatment against V. destructor was studied through a behavioural and toxicological approach at the individual level. On one hand, we confirmed the altered morphology for the arolia of mites and studied the evolution of the process over time. On the other hand, we found that haemolymph contaminated with lactic acid did not kill the feeding parasitic mite. These findings support a local mode of action. In order to unravel the sequence of events leading to the local contact between the acid and the mite on bees, we also documented the olfactory valence of lactic acid for A. mellifera and V. destructor. This work provides a new comprehension of lactic acid activity against the parasitic mite through honey bee exposure and gives new opportunities for control strategies against V. destructor.