Honey Bee Body Research Articles

Interplay between Selenium, selenoprotein genes, and oxidative stress in honey bee Apis mellifera L.

The honey bee, Apis mellifera L., is a major pollinator insect that lacks novel “selenoprotein genes”, rendering it susceptible to elevated levels of Selenium (Se) occurring naturally in the environment. We investigated the effects of two inorganic forms of Se on biological traits, oxidative stress, and gene regulation. Using bioassay arenas in the laboratory, one-day old sister bees were fed ad libitum 4 different concentrations of selenate and selenite, two common inorganic forms of Se. The transcription levels of 4 honey bee antioxidant genes were evaluated, and three putative selenoprotein-like genes (SELENOT, SELENOK, SELENOF) were characterized as well as Sbp2, a Selenium binding protein required for the translation of selenoproteins mRNA. Oxidative stress and Se residues were subsequently quantified in honey bee bodies throughout the experiment.Se induced higher oxidative stress in treated honey bees leading to a significantly elevated protein carbonyl content, particularly at the highest studied concentrations. Early upregulations of Spb2 and MsrA were identified at day 2 of the treatment while all genes except SELENOT were upregulated substantially at day 8 to alleviate the Se-induced oxidative stress levels. We determined that doses between 60 and 600 mg.Se.L−1 were acutely toxic to bees (<48 h) while doses between 0.6 and 6 mg.Se.L−1 led to much lower mortality (7–16)%. Furthermore, when fed ad libitum, Se residue data indicated that bees tolerated accumulation up to 0.12 µg Se bee−1 for at least 8 days with a Se LC50 of ∼6 mg/L, a field realistic concentration found in pollen of certain plants in a high Se soil environment.

Reduced thermal variability in cities and its impact on honey bee thermal tolerance.

Urbanization is one of the most significant land cover transformations, and while climate alteration is one of its most cited ecological consequences we have very limited knowledge on its effect on species’ thermal responses. We investigated whether changes in environmental thermal variability caused by urbanization influence thermal tolerance in honey bees (Apis mellifera) in a semi-arid city in central Mexico. Ambient environmental temperature and honey bee thermal tolerance were compared in urban and rural sites. Ambient temperature variability decreased with urbanization due to significantly higher nighttime temperatures in urban compared to rural sites and not from differences in maximum daily temperatures. Honey bee thermal tolerance breadth [critical thermal maxima (CTmax)—critical thermal minima (CTmin)] was narrower for urban bees as a result of differences in cold tolerance, with urban individuals having significantly higher CTmin than rural individuals, and CTmax not differing among urban and rural individuals. Honey bee body size was not correlated to thermal tolerance, and body size did not differ between urban and rural individuals. We found that honey bees’ cold tolerance is modified through acclimation. Our results show that differences in thermal variability along small spatial scales such as urban-rural gradients can influence species’ thermal tolerance breadths.

Mineral composition of the organism tissues and honeycombs of melliferous bees under the conditions of feeding them soybean flour and citrates of Cobalt and Nickel

The inadequacy of mineral nutrition leads to inhibition of physiological and metabolic reactions in the body of honeybees. It is known that Cobalt chloride is used to activate oviposition of the queen bee. It was established that Cobalt and Nickel citrate, obtained by the method of nanotechnology, corrects the mineral metabolism and affects the metabolism of bees. It is known that Cobalt plays an important role in the work of enzymes; synthesis of vitamin B12, promotes assimilation of vitamins A, E, C; increases protein metabolism, participates in hematopoiesis. Nickel also has a pronounced effect on hemopoiesis, namely on the morphological composition of blood. But its effect on the cell and subcellular level is not well understood. The results of studies of the effect of soybean flour with the addition of Cobalt and Nickel citrates on the content of mineral elements in the tissues of the body of bees and honeycombs are given. The research was carried out in the farms in the Lviv region, in April-May at the bees of the Carpathian breed. It was established that the content of Ferrum, Cuprum and Germanium in the tissues of bees increases with the addition of soybean flour with Сobalt citrate at a dose of 2 mg per 500 g of soy flour. When Nickel citrate was added to the feed at a dose of 1 mg per 500 g of soy flour, the content of Ferrum and Cuprum increased in honeycombs. The complex combination of Citrits Co and Ni, soy flour with sugar syrup was characterized by a decrease in the level of Zn in the tissues of the bees compared to its contents in the control group samples. In samples of biological material, the content of Сobalt, Nickel and the essential elements Cuprum, Zink, Ferrum, Selenium, Germanium was determined by atomic emission spectrometry with inductively coupled plasma. Citrates of the microelements were produced by the method of M. Kosinov and V. Kaplunenkо.

Вплив препарату «Шумерське срібло» на життєздатність медоносних бджіл та вміст окремих мікроелементів в їх організмі

Вплив препарату «Шумерське срібло» на життєздатність медоносних бджіл та вміст окремих мікроелементів в їх організмі

Compound and Dose-Dependent Effects of Two Neonicotinoid Pesticides on Honey Bee (Apis mellifera) Metabolic Physiology.

Use of neonicotinoid pesticides is now ubiquitous, and consequently non-targeted arthropods are exposed to their residues at sub-lethal doses. Exposure to these neurotoxins may be a major contributor to poor honey bee colony health. Few studies have explored how sub lethal exposure to neonicotinoids affects honey bee metabolic physiology, including nutritional and energetic homeostasis, both of which are important for maintaining colony health. Reported here are results from a study of chronic oral exposure of honey bees to two sub lethal concentrations of clothianidin and imidacloprid. Neonicotinoids altered important aspects of honey bee nutritional and metabolic physiology in a compound and dose-dependent manner; both compounds at low doses reduced honey bee body weight. Low-dose clothianidin exposure resulted in bees having protein, lipids, carbohydrates, and glycogen levels similar to newly emerged bees. High-dose clothianidin exposure lowered lipids and glycogen content of bees. High-dose imidacloprid exposure resulted in bees having depressed metabolic rate. Low-dose imidacloprid exposure resulted in bees consuming low and high levels of protein and carbohydrate rich foods, respectively. Results suggest neonicotinoids interfere with honey bee endocrine neurophysiological pathways. Compound and dose-dependent effects might represent respective chemical structural differences determining an observed effect, and thresholds of compound effects on honey bee physiology.

Вплив кліща Varroa destructor на показники гемолімфи медоносних бджіл

Наведено результати експериментальних досліджень щодо впливу збудника вароозу на кількісний склад формених елементів гемолімфи інвазованих бджіл з урахуванням їх вікових особливостей. Встановлено, що кількісні показники гемоцитів у бджіл, уражених Varroa destructor, характеризуються зниженням відсотку пролейкоцитів (на 2,5–32,2 %) та зростанням відсотку нейтрофільних та еозинофільних фагоцитів (на 8,2–20,6 %). Кількість секреторних клітин сферулоцитів у гемолімфі інвазованих бджіл змінювалася залежно від їх віку – знижувалася у бджіл одно- та дванадцятиденного віку (на 8,5 та 4,9 %) і зростала у бджіл чотири- та восьмиденного віку (на 7,7 та 16,6 %).&#x0D; Analysis of the cellular composition of hemolymph is of great importance for assessing the physiological state of the bees. This is due to the fact that the composition of hemocytes of the hemolymph is variable, which depends on the age, season of the year, as well as in various diseases and the impact of adverse environmental factors. Studies of domestic scientists have shown that varroosis of bees significantly affects the hemolymph indices of honeybees. A hemolymph like the blood of animals shows not only the physiological, but also the pathological changes in the body of the bees. So scientific and practical interest is the study of the effect of varooza invasion on the body of honey bees, taking into account their age.&#x0D; In this connection, the purpose of the study was to determine the effect of the Varroa destructor mite on the composition of hemolymph of infested bees. The studies were being conducted during 2018 in the conditions of a private apiary in the Grebenkovsky district of the Poltava region. The object of the study were the bees of the same age, which were obtained by incubating of the printed brood. 8 groups were formed: 4 research groups which bees affected by the Varroa destructor mite of different ages (one, four, eight and twelve days of age) and 4 control groups which bees were free from a mite of similar age.&#x0D; From each group were taken 15 hemolymph samples (120 samples in total).&#x0D; According to the results of the conducted research, it has been established that the Varroa destructor mites significantly affect the physiological state of the infested bees, namely, the indicators of the hemolymph formed elements. Invasion is revealed by a decrease in progenitor cells (proleukocyte and growth of phagocytes), which indicate the activation of the immune system of bees, as well as the toxic effect of invasion of pathogens. It has been proven that the age of bees has a significant effect on the bees' immune response to varroosis, as evidenced by the dynamics of secretory cells (the spherulites in bees hemolymph). It was found that the age ratio of hemolymph in bees over varroosis significantly increases (up to 28.6%), which indicates the depletion of the insects’ body.&#x0D; Prospects for further research is to determine the effect of Varroa destructor on the state of the fat body and the lifespan of honeybees.

Mineral and lipid composition the body of the honeybees organism and the biological value of honey in the summer-autumn period under the conditions of feeding honey bees by citrate-capped silver and copper nanoparticles

The article presents the results of investigations of individual mineral elements – Fe, Zn, Cu, Cr, Co, Pb, Cd in the tissues of the honeybees, common lipids and the ratio of their classes in the body of honey bees and the biological value of honey under the conditions of feeding of honey bees by citrate-capped silver and copper nanoparticlescitrates. The research was conducted on the honey bees of the Carpathian race on the basis of the apiary of the Stepan Gzhytskyi National University of Veterinary Medicine and Biotechnologies Lviv in the summer-autumn period in 5 groups of bee colonies, formed on the principle of analogues, by three bees colony in each group. Control group (I) received a sugar syrup in 1:1 concentration (1000 ml/bee/week). Experimental group (II) additionally added to the syrup Ag in the amount of 0.5 mg/l of sugar syrup, the third experimental group – under similar conditions received Ag in the amount of 1 mg/l, IV group received 0.5 mg of sugar Cu syrup/l and V–Cu in the amount of 1 mg/l of sugar syrup. The trace elements were injected into a sugar syrup in the form of citrates obtained by the nanotechnology method from LLC Nanomaterials and Nanotechnologies, Kyiv. Research period lasted 28 days at a feeding interval of 7 days. According to the research data, certain intergroup differences in the content of mineral elements in the bee organism have been established: the increase of Fe, Co, Cr content in the background of a probable decrease Zn in the samples of the whole body tissues of the IV and V experimental groups. Pb decrease in the content of the tissues of the body of all experimental groups with a high probability in the IV and V experimental groups (P &lt; 0.02) was observed, as well as a tendency to decrease the level of Cd in the tissues of the whole organism in all experimental groups compared with the control group. According to the results of the conducted studies, the growth of the content of common lipids in the whole of the bees is observed and the probable differences in the fractional distribution of lipids are expressed. In particular, in the tissues of bees of all experimental group, higher levels of phospholipids and triacylglycerols were observed against the background of a decrease in the relative content of monodiacylglycerols, cholesterol. Feeding with sugar honey bees by citrate-capped silver and copper nanoparticles in the summer-autumn period was characterized by certain differences in the content of individual trace elements in honey in all experimental groups, in particular, higher content of Fe, Cu, Co in samples of honey IV and V experimental groups and decrease in the concentration of Cr, Pb, Cd. According to physico-chemical parameters, in honey of experimental groups, there were probably higher differences in the content of amino acids of proline, diastase activity, and a decrease in pH, water. The content of proline in samples of honey III and IV experimental groups was higher on 22.6% and 16.9% (P &lt; 0.05–0.001) compared to control. In samples of honey II–V in experimental groups, diastase activity increased in 1.7–2.2 times (P &lt; 0.01–0.001), while fluctuations of pH of honey by 4.0–5.0% (P &lt; 0.001) were comparatively to control. Thereby, feeding with sugar syrup citrate-capped silver and copper nanoparticles, in doses of 0.5 and 1 mg, caused a certain corrective effect on the content of Fe, Zn, Cu, Cr, Co, and antagonistic effects on Pb, Cd in tissues and production of honey bees.

Comparison of the contents of selected elements and pesticides in honey bees with regard to their habitat

The inspiration for this study was the anxiety of Warsaw beekeepers, who raised the question whether location of hives in large urban agglomerations results in changes in concentrations of xenobiotics, toxic elements, and micronutrients in honey bees. Preliminary studies required elaboration of the research methodology, as the studied object is characterized by a low degree of homogeneity and the method of sample preparation affects obtained results. From many tested approaches, the use of washed and milled abdomens of the bees is recommended. Results obtained for such prepared samples are slightly lower than for whole bees, but their repeatability is higher, which enables easier interpretation of the trends and comparison of different locations. The contents of selected elements (As, Al, Cd, Co, Cr, Cu, Mn, Pb, and Zn) were compared in bees from urban and rural areas. The studies were supported by pesticides analysis. Also, it was checked whether these substances are accumulated on the surface or inside the bee’s body. The research indicates the markers of contamination: Al, As, and Cr on the surface and Cd inside the bodies of honey bees. The location of the hives does not influence significantly the content of “toxic,” nutrient metals and metalloids in bees (slightly higher levels of As, Al, Pb, and Cd were found in bees from urban areas). In terms of exposure to these elements and pesticides, the large city environment is not harmful for honey bees.

1.22 Weight differences of honey bees after administration of sublethal doses of dimethoate

Background: The aim of this work was to assess honey bee body weight as a possible further parameter to detect effects in a 10 day chronic feeding study according to OECD 2451 following exposure to sublethal concentrations of a plant protection product (i.e. dimethoate). This investigation is based on the assumption that weight differences might be caused by chronic feeding of dimethoate. Two set of tests in two different laboratories (Lab 1 and Lab 2) were conducted in order to investigate possible weight changes of complete adult honey bees and/or parts of their body (honey stomach and intestine) following treatment of dimethoate. Bees were weighed before and after chronic feeding of sub-lethal concentrations of dimethoate. Results: Differences in the number of bees which lost weight following treatment of sublethal concentrations of dimethoate was found in Lab 1, but could not confirmed in Lab 2. The difference in weight between the control group and the dimethoate treatment could only be detected as a statistical significant difference in one lab at the highest concentration (0.4 mg/kg). Assessment of weight changes of parts of the bee body (honey stomach and intestine) shows a very high variation (CV) which makes interpretation of the data of the total body weight questionable. Conclusion: The results of the two laboratories were contradictory and no conclusive assessment can be done following the two sets of experiments. Assessment of bee body weight within a 10-day chronic feeding study is considered questionable for the detection of sublethal effects. Further work with other active ingredients is needed to clarify if body weight change of honey bees can be used as a parameter for sublethal effects.

Assessment of spatial and temporal variations in trace element concentrations using honeybees (Apis mellifera) as bioindicators

With the increase in anthropogenic activities metal pollution is also increased and needs to be closely monitored. In this study honeybees were used as bioindicators to monitor metal pollution. Metal pollution in honeybees represents pollution present in air, water and soil. Concentrations of As, Cs, Hg, Mo, Sb, Se, U and V were measured. The aim of this study was to assess spatial and temporal variations of metal concentrations in honeybees. Samples of honeybees were taken at five different regions in Serbia (Belgrade - BG, Pančevo - PA, Pavliš - PV, Mesić - MS, and Kostolac - TPP) during 2014. Spatial variations were observed for Sb, which had higher concentrations in BG compared to all other regions, and for U, with higher concentrations in the TPP region. High concentrations of Sb in BG were attributed to intense traffic, while higher U concentrations in the TPP region are due to the vicinity of coal fired power plants. In order to assess temporal variations at two locations (PA and PV) samples were taken during July and September of 2014 and June, July, August and September of 2015. During 2014 observing months of sampling higher concentrations in July were detected for Sb and U in BG, which is attributed to lifecycle of plants and honeybees. During the same year higher concentrations in September were observed for As, Sb in PA and Hg in PV. This is due to high precipitation during the peak of bee activity in spring/summer of 2014. No differences between months of sampling were detected during 2015. Between 2014 and 2015 statistically significant differences were observed for Hg, Mo and V; all elements had higher concentrations in 2014. This is in accordance with the trend of reduction of metal concentrations in the bodies of honeybees throughout the years in this region.

Features of histolism and hystogenesis in the vital temperature range in the organism of honey bee (Apis mellifera L.) in the postembrional period

The productivity of bee families depends to a large extent on the influence of exogenous factors. The most important ones include: the presence of a honey-bearing base, climatic conditions, temperature of the environment, etc. It significantly affects the growth of families and the stability of the microclimate in the nest. The welcome temperature range in the postembryonic period fluctuates within 30–38 °С. Therefore, the purpose of the work was to find out the physiological and biochemical peculiarities of the adaptation of the body of honeybee bees under the influence of the lowered temperature in the nest. For research, two groups of honeybees were selected that differed in terms of maintenance. The control group was constantly in the nest of the bee family, and the experimental at the stage of the prepupa was placed in a thermostat where the temperature was maintained at 32 °С. Materials for researches were tissues of prepupa and pupa. The method of thin-layer chromatography identifies the classes of lipids, phospholipids and cholesterol. Based on the performed researches, it was found that the violation of the optimal parameters of the microclimate in the post-embryonal period affects the increase in the weight of the prepupa of the body by 19.4% (P < 0 . 001) and the decrease in the intensity of the processes of dehydration in tissues by 63 . 8% (P < 0 . 05), which is associated with the accumulation of bound water in cells. It is proved that the decrease of the optimum temperature of the incubation of the breeding breed at 2 °С leads to prolongation of the post-embryonic development period by 35–42 hours. Under such conditions, throughout the period of incubation in bees, high levels of total lipids are observed. At the stage of prepupa, the number of triacylglycerols in the lipids increases by 49 . 0% (P < 0 . 001). In ontogenesis in pupa tissues, a gradual decrease in the content of triacylglycerols, including the imaging stage, is evidently due to the effect of the stress factor. It was found that lowering the temperature on the second day of incubation of the breeding plant reduces the content of phospholipids in the lipid tissues by 11 . 9% (P ˂ 0 . 05). At the same time, the decrease in the content of lysophosphatidylcholine was detected by 6 . 6% (P < 0 . 001). The violation of the optimum temperature during the development of bees leads to a steady increase in the content of esterified cholesterol by an average of 47 . 9% (P < 0 . 01). In the process of pupa formation, the ratio of classes of esterified cholesterol is changing. The conducted studies allow to correct the metabolic processes in the body of honey bees in order to adapt them to the lowered temperatures.

Exo- and Endogenous Water in the Honeybee Body (Apis mellifera, Hymenoptera, Apidae)

The exo- and endogenous water content in the honeybee body was studied in relation to age, season, and the physiological state of the bee colony. The water content in the carbohydrate food consumed by the bees was shown to affect brood production in the colony. The behavior of the bees supplying the colony with water was investigated and the amount of water used for larval food dilution and nest cooling was estimated. Seasonal interruption and resumption of the reproductive functions of the queen were shown to depend on the dynamics of the water content in the digestive tract of worker bees.

Honeybees (Apis mellifera) as a biological barrier for contamination of honey by environmental toxic metals.

The aim of the study was to investigate the transfer of toxic metals from honeybee workers (Apis mellifera L.) to bee honey in relation to the ecological state of the environment. The materials of the study consisted of samples of honeybee bodies and varietal honeys taken from the same apiary located in three areas: R1-urbanized (16), R2-ecologically clean (16) and R3-industrialized (15) of south-eastern Poland. The contents of 14 elements in all tested samples, including toxic metals (Cd, Pb, Hg, Al, Ni, Tl) as well as bioelements (K, Mg, Ca, Mn, Fe, Zn, Cu, Se), were analysed by the ICP-OES method with prior microwave mineralization. The concentrations of the majority of the studied elements, excluding aluminum and lead, were significantly higher in bee bodies than in honey samples (P < 0.05). The pollution of bee bodies by toxic metals was dependent on the environmental cleanliness, and the most pollution was observed in the industrialized area. The bee body was the most effective barrier for Cd and Tl transfer to the honey, while the level of Ni was similar in both tested materials. The Al concentration was significantly higher in honey than bee bodies (14.81 ± 24.69 and 6.51 ± 5.83mgkg-1, respectively), which suggests the possibility of secondary contamination of honey. The greatest sensitivity to heavy metal pollution was observed in honeydew honey compared to nectar honeys (P < 0.05). It was proved for the first time that bees work as biofilters for toxic metals and prevent honey contamination.

Use of honeybees (Apis mellifera L.) as bioindicators for assessment and source appointment of metal pollution.

The ability of honeybees to collect particulate matter (PM) on their bodies makes them outstanding bioindicators. In this study, two cities, Pančevo (PA) and Vršac (VS), South Banat district, Vojvodina, Serbia, were covered with two sampling sites each. The aims of this study were to determine concentrations of Al, Ba, Cd, Co, Cr, Cu, Fe, Mn, Na, Ni, Sr, and Zn in the bodies of honeybees during July and September of 2013, 2014, and 2015 and to analyze their spatial and temporal variations and sources of analyzed elements, as well as to assess pollution levels in the two cities. Significant temporal differences were found for Al, Ba, Cd, Co, Cr, Cu, Fe, Mn, Na, Ni, and Zn. Trend of reduction in metal concentrations in bodies of honeybees during the years was observed. Statistically significant spatial variations were observed for Al, Ba, and Sr, with higher concentrations in VS. PCA and CA analyses were used for the first time to assess sources of metals found in honeybees. These analyses showed two sources of metals. Co, Cd, Na, Fe, Mn, Zn, and partly Cu were contributed to anthropogenic sources, while Ca, Al, Mg, Cr, Ba, Sr, and Ni were contributed to natural sources.

Experience during early adulthood shapes the learning capacities and the number of synaptic boutons in the mushroom bodies of honey bees (Apis mellifera).

The honey bee mushroom bodies (MBs) are brain centers required for specific learning tasks. Here, we show that environmental conditions experienced as young adults affect the maturation of MB neuropil and performance in a MB-dependent learning task. Specifically, olfactory reversal learning was selectively impaired following early exposure to an impoverished environment lacking some of the sensory and social interactions present in the hive. In parallel, the overall number of synaptic boutons increased within the MB olfactory neuropil, whose volume remained unaffected. This suggests that experience of the rich in-hive environment promotes MB maturation and the development of MB-dependent learning capacities.

Ecological stoichiometry of the honeybee: Pollen diversity and adequate species composition are needed to mitigate limitations imposed on the growth and development of bees by pollen quality.

The least understood aspects of the nutritional needs of bees are the elemental composition of pollen and the bees’ need for a stoichiometrically balanced diet containing the required proportions of nutrients. Reduced plant diversity has been proposed as an indirect factor responsible for the pollinator crisis. We suggest stoichiometric mismatch resulting from a nutritionally unbalanced diet as a potential direct factor. The concentrations and stoichiometric ratios of C, N, S, P, K, Na, Ca, Mg, Fe, Zn, Mn, and Cu were studied in the bodies of honeybees of various castes and sexes and in the nectar and pollen of various plant species. A literature review of the elemental composition of pollen was performed. We identified possible co-limitations of bee growth and development resulting mainly from the scarcity of Na, S, Cu, P and K, and possibly Zn and N, in pollen. Particular castes and sexes face specific limitations. Concentrations of potentially limiting elements in pollen revealed high taxonomic diversity. High floral diversity may be necessary to maintain populations of pollen eaters. Single-species crop plantations, even if these species are rich in nectar and pollen, might limit bee growth and development, not allowing for gathering nutrients in adequate proportions. However, particular plant species may play greater roles than others in balancing honeybee diets. Therefore, we suggest specific plant species that may (1) ensure optimal growth and production of individuals by producing pollen that is exceptionally well balanced stoichiometrically (e.g., clover) or (2) prevent growth and development of honeybees by producing pollen that is extremely unbalanced for bees (e.g., sunflower). Since pollen is generally poor in Na, this element must be supplemented using “dirty water”. Nectar cannot supplement the diet with limiting elements. Stoichiometric mismatch should be considered in intervention strategies aimed at improving the nutritional base for bees.

Heat Perception and Aversive Learning in Honey Bees: Putative Involvement of the Thermal/Chemical Sensor AmHsTRPA.

The recent development of the olfactory conditioning of the sting extension response (SER) has provided new insights into the mechanisms of aversive learning in honeybees. Until now, very little information has been gained concerning US detection and perception. In the initial version of SER conditioning, bees learned to associate an odor CS with an electric shock US. Recently, we proposed a modified version of SER conditioning, in which thermal stimulation with a heated probe is used as US. This procedure has the advantage of allowing topical US applications virtually everywhere on the honeybee body. In this study, we made use of this possibility and mapped thermal responsiveness on the honeybee body, by measuring workers' SER after applying heat on 41 different structures. We then show that bees can learn the CS-US association even when the heat US is applied on body structures that are not prominent sensory organs, here the vertex (back of the head) and the ventral abdomen. Next, we used a neuropharmalogical approach to evaluate the potential role of a recently described Transient Receptor Potential (TRP) channel, HsTRPA, on peripheral heat detection by bees. First, we applied HsTRPA activators to assess if such activation is sufficient for triggering SER. Second, we injected HsTRPA inhibitors to ask whether interfering with this TRP channel affects SER triggered by heat. These experiments suggest that HsTRPA may be involved in heat detection by bees, and represent a potential peripheral detection system in thermal SER conditioning.

A Simple, Cost-effective Method to Prepare High-volume Honey Bee Body Parts for Morphometric Analysis

Preparing body parts for taking morphological measurements is a time-consuming problem, especially in cases where thousands of parts must be mounted and measured. The traditional method of mounting...

Nutritional aspects of honey bee-collected pollen and constraints on colony development in the eastern Mediterranean

Pollen is the main protein and lipid source for honey bees (Apis mellifera), and nutritionally impoverished landscapes pose a threat to colony development. To determine colony nutritional demands, we analyzed a yearly cycle of bee-collected pollen from colonies in the field and compared it to colony worker production and honey bee body composition, for the first time in social insects. We monitored monthly bee production in ten colonies at each of seven sites throughout Israel, and trapped pollen bi-monthly in five additional colonies at each of four of these sites. Pollen mixtures from each sampling date and site were analyzed for weight, total protein, total fatty acids (FAs), and FA composition. Compared to more temperate climates, the eastern Mediterranean allows a relatively high yearly colony growth of ca. 300,000–400,000 bees. Colonies at higher elevation above sea level showed lower growth rates. Queen egg-laying rate did not seem to limit growth, as peaks in capped brood areas showed that queens lay a prolific 2000 eggs a day on average, with up to 3300 eggs in individual cases. Pollen uptake varied significantly among sites and seasons, with an overall annual mean total 16.8kg per colony, containing 7.14kg protein and 677g fat. Overall mean pollen protein content was high (39.8%), and mean total FA content was 3.8%. Production cost, as expressed by the amount of nutrient used per bee, was least variable for linoleic acid and protein, suggesting these as the best descriptive variables for total number of bees produced. Linolenic acid levels in pollen during the autumn were relatively low, and supplementing colonies with this essential FA may mitigate potential nutritional deficiency. The essentiality of linoleic and linolenic acids was consistent with these FAs’ tendency to be present at higher levels in collected pollen than in the expected nutrients in bee bodies, demonstrating a well-developed adjustment between pollinator nutritional demands and the nutritional value of food offered by pollinated plants.

Pesticide residues in honeybees, honey and bee pollen by LC–MS/MS screening: Reported death incidents in honeybees

The aim of this study was to investigate reported cases of honeybee death incidents with regard to the potential interrelation to the exposure to pesticides. Thus honeybee, bee pollen and honey samples from different areas of Greece were analyzed for the presence of pesticide residues. In this context an LC–ESI-MS/MS multiresidue method of total 115 analytes of different chemical classes such as neonicotinoids, organophosphates, triazoles, carbamates, dicarboximides and dinitroanilines in honeybee bodies, honey and bee pollen was developed and validated. The method presents good linearity over the ranges assayed with correlation coefficient values r2≥0.99, recoveries ranging for all matrices from 59 to 117% and precision (RSD%) values ranging from 4 to 27%. LOD and LOQ values ranged – for honeybees, honey and bee pollen – from 0.03 to 23.3ng/g matrix weight and 0.1 up to 78ng/g matrix weight, respectively. Therefore this method is sufficient to act as a monitoring tool for the determination of pesticide residues in cases of suspected honeybee poisoning incidents. From the analysis of the samples the presence of 14 active substances was observed in all matrices with concentrations ranging for honeybees from 0.3 to 81.5ng/g, for bee pollen from 6.1 to 1273ng/g and for honey one sample was positive to carbendazim at 1.6ng/g. The latter confirmed the presence of such type of compounds in honeybee body and apicultural products.