Dimorphic antennal systems in gynandromorphic honey bees,Apis Mellifera l. (Hymenoptera: Apidae)

Gynandromorphic honey bees, Apis mellifera (Hymenoptera: Apidae), were examined to determine characteristic morphological and anatomical features of the antennal system. The antennae of gynandromorphic individuals are predominantly worker or drone-like. Hybrid antennae, composed of female and male tissues, occur only rarely (7 out of 188 examined antennae). Depending on the mosaic pattern of the head, both antennae can be drone-like or worker-like, or one can be drone-like and the other worker-like. Examination of the antennal lobes of six characteristic specimens revealed that antennal lobes, which are innervated by drone-like antennae, always have drone-specific enlarged tracts and macroglomerular complexes, whereas antennal lobes innervated by worker-like antennae always are composed of normally sized glomeruli. Thus, there is a strict correlation between the sexual morphology of the antennae and the sexual organization of the antennal lobe neuropil. In one antennal lobe, innervated by a hybrid antenna, we found a hypertrophied glomerulus, certainly homologous to one of the macroglomerular complexes in drone-like antennal lobes.jy 1999 Elsevier Science Ltd. All rights reserved.     

Flower visitation patterns of the coexisting honey bees Apis cerana japonica and Apis mellifera (Hymenoptera: Apidae)

We compared flower visitation patterns of two coexisting honey bees, Apis mellifera Linnaeus and Apis cerana japonica Radoszkowski, on 20 plant species, including three exotics, under natural conditions in Nara, Japan, from April to August 2012. We also measured flower color based on bee color vision (15 flower species), nectar volume (nine species) and nectar concentration (eight species). Flowers colored white, pink, red, purple and cream were classified as bee‐blue‐green, and yellow was classified as bee‐green. Apis cerana visited 14 plant species and A. mellifera visited 11. Although the two Apis species are similar in morphology, they visited different plants: in particular, A. cerana visited native plant species more often than did A. mellifera. Both A. mellifera and A. cerana visited not only nectariferous flowers but also those with no nectar. We also found different visitation patterns between A. cerana and A. mellifera: Apis cerana more often visited flowers with smaller color angle (bee‐blue‐green), lower chroma and higher brightness, and flowers secreting nectars of higher concentration and smaller volume than did A. mellifera.     

Impact of the introduced honey bee (Apis mellifera) (Hymenoptera: Apidae) on native bees: A review

Abstract Interspecific competition for a limited resource can result in the reduction of survival, growth and/or reproduction in one of the species involved. The introduced honey bee (Apis mellifera Linnaeus) is an example of a species that can compete with native bees for floral resources. Often, research into honey bee/native bee competition has focused on floral resource overlap, visitation rates or resource harvesting, and any negative interaction has been interpreted as a negative impact. Although this research can be valuable in indicating the potential for competition between honey bees and native bees, to determine if the long‐term survival of a native bee species is threatened, fecundity, survival or population density needs to be assessed. The present review evaluates research that has investigated all these measurements of honey bee/native bee competition and finds that many studies have problems with sample size, confounding factors or data interpretation. Guidelines for future research include increasing replication and using long‐term studies to investigate the impact of both commercial and feral honey bees.     

Heat stress during development affects immunocompetence in workers,queens and drones of Africanized honey bees (Apis mellifera L.) (Hymenoptera: Apidae)

Though social insects generally seem to have a reduced individual immunoresponse compared to solitary species, the impact of heat stress on that response has not been studied. In the honey bee, the effect of heat stress on reproductives (queens and males/drones) may also vary compared to workers, but this is currently unknown. Here, we quantified the activity of an enzyme linked to the immune response in insects and known to be affected by heat stress in solitary species: phenoloxidase (PO), in workers, queens and drones of Africanized honey bees (AHBs) experimentally subjected to elevated temperatures during the pupal stage. Additionally, we evaluated this marker in individuals experimentally infected with the entomopathogenic fungus Metarhizium anisopliae. Differences in PO activity were found between sexes and castes, with PO activity generally higher in workers and lower in reproductives. Such differences are associated with the likelihood of exposure to infection and the role of different individuals in the colony. Contrary to our expectation, heat stress did not cause an increase in PO activity equally in all classes of individual. Heat stress during the pupal stage significantly decreased the PO activity of AHB queens, but not that of workers or drones, which more frequently engage in extranidal activity. Experimental infection with Metarhizium anisopliae reduced PO activity in queens and workers, but increased it in drones. Notably, heat stressed workers lived significantly shorter after infection despite exhibiting greater PO activity than queens or drones. We suggest that this discrepancy may be related to trade-offs among immune response cascades in honey bees such as between heat shock proteins and defensin peptides used in microbial defence. Our results provide evidence for complex relationships among humoral immune responses in AHBs and suggest that heat stress could result in a reduced life expectancy of individuals.     

Organization of the antennal lobe in the queen honey bee,Apis mellifera L. (Hymenoptera : Apidae)

Antennal afferent pathway topography was studied in the queen honey bee, Apis mellifera L. (Hymenoptera : Apidae) by staining with cobalt chloride applied directly to the cut antennal axons. Antennal lobe organization in the queen was compared with those in worker and drone bees. The organization is similar in queen and worker bees. For the first time in a female insect the possible existence of a macroglomerulus is shown, which may be involved in the processing of species-specific information. A comparative quantitative neuromorphological study of the glomeruli was performed between young queens (8-day old) and 1-yr-old queens. The mean volume of the glomeruli is 46% greater in the older queens.     

Projection pattern of poreplate sensory neurones in honey bee worker,Apis mellifera L. (Hymenoptera : Apidae)

The projections of olfactory receptor cells of the poreplate sensilla were studied in the worker honey bee, Apis mellifera L. (Hymenoptera : Apidae) by filling single sensilla iontophoretically with cobalt chloride. Successful fillings of individual sensilla lead to staining of one to 22 sensory neurones. All stained receptor cell axons are uniglomerular. Seven fillings of poreplates from the 5th flagellar segment in different animals were compared to analyse the distribution patterns of the receptor cell axons in the antennal lobe. The sensory neurones of individual poreplates project to widely distributed glomeruli in the antennal lobe. The projection patterns of different poreplates are not the same, but may be overlapping.     

Alarm pheromone perception in honey bees is decreased by smoke (Hymenoptera: Apidae)

The application of smoke to honey bee(Apis mellifera) antennae reduced the subsequent electroantennograph response of the antennae to honey bee alarm pheromones, isopentyl acetate, and 2-heptanone. This effect was reversible, and the responsiveness of antennae gradually returned to that of controls within 10–20 min. A similar effect occurred with a floral odor, phenylacetaldehyde, suggesting that smoke interferes with olfaction generally, rather than specifically with honey bee alarm pheromones. A reduction in peripheral sensitivity appears to be one component of the mechanism by which smoke reduces nest defense behavior of honey bees.     

Miocene honey bees from the Randeck Maar of southwestern Germany (Hymenoptera, Apidae)

The Miocene Randeck Maar (southwestern Germany) is one of the only sites with abundant material of fossil honey bees. The fauna has been the focus of much scrutiny by early authors who recognized multiple species or subspecies within the fauna. The history of work on the Randeck Maar is briefly reviewed and these fossils placed into context with other Tertiary and living species of the genus Apis Linnaeus (Apinae: Apini). Previously unrecorded specimens from Randeck Maar were compared with earlier series in an attempt to evaluate the observed variation. A morphometric analysis of forewing venation angles across representative Recent and Tertiary species of Apis as well as various non-Apini controls was undertaken to evaluate the distribution of variation in fossil honey bees. The resulting dendrogram shows considerable variation concerning the wing venation of Miocene Apini, but intergradation of other morphological characters reveals no clear pattern of separate species. This suggests that a single, highly variable species was present in Europe during the Miocene. The pattern also supports the notion that the multiple species and subspecies proposed by earlier authors for the Randeck Maar honey bee fauna are not valid, and all are accordingly recognized as Apis armbrusteri Zeuner.     

An experiment on comb orientation by honey bees (Hymenoptera: Apidae) in traditional hives

The orientation of combs in traditional beehives is extremely important for obtaining a marketable honey product. However, the factors that could determine comb orientation in traditional hives and the possibilities of inducing honey bees, Apis mellifera (L.), to construct more desirable combs have not been investigated. The goal of this experiment was to determine whether guide marks in traditional hives can induce bees to build combs of a desired orientation. Thirty-two traditional hives of uniform dimensions were used in the experiment. In 24 hives, ridges were formed on the inner surfaces of the hives with fermented mud to obtain different orientations, circular, horizontal, and spiral, with eight replicates of each treatment. In the remaining eight control hives, the inner surface was left smooth. Thirty-two well-established honey bee colonies from other traditional hives were transferred to the prepared hives. The colonies were randomly assigned to the four treatment groups. The manner of comb construction in the donor and experimental hives was recorded. The results showed that 22 (91.66%) of the 24 colonies in the treated groups built combs along the ridges provided, whereas only 2 (8.33%) did not. Comb orientation was strongly associated with the type of guide marks provided. Moreover, of the 18 colonies that randomly fell to patterns different from those of their previous nests, 17 (94.4%) followed the guide marks provided, irrespective of the comb orientation type in their previous nest. Thus, comb orientation appears to be governed by the inner surface pattern of the nest cavity. The results suggest that even in fixed-comb hives, honey bees can be guided to build combs with orientations suitable to honey harvesting, without affecting the colonies.     

Large-scale field application of RNAi technology reducing Israeli acute paralysis virus disease in honey bees (Apis mellifera, Hymenoptera: Apidae)

The importance of honey bees to the world economy far surpasses their contribution in terms of honey production; they are responsible for up to 30% of the world's food production through pollination of crops. Since fall 2006, honey bees in the U.S. have faced a serious population decline, due in part to a phenomenon called Colony Collapse Disorder (CCD), which is a disease syndrome that is likely caused by several factors. Data from an initial study in which investigators compared pathogens in honey bees affected by CCD suggested a putative role for Israeli Acute Paralysis Virus, IAPV. This is a single stranded RNA virus with no DNA stage placed taxonomically within the family Dicistroviridae. Although subsequent studies have failed to find IAPV in all CCD diagnosed colonies, IAPV has been shown to cause honey bee mortality. RNA interference technology (RNAi) has been used successfully to silence endogenous insect (including honey bee) genes both by injection and feeding. Moreover, RNAi was shown to prevent bees from succumbing to infection from IAPV under laboratory conditions. In the current study IAPV specific homologous dsRNA was used in the field, under natural beekeeping conditions in order to prevent mortality and improve the overall health of bees infected with IAPV. This controlled study included a total of 160 honey bee hives in two discrete climates, seasons and geographical locations (Florida and Pennsylvania). To our knowledge, this is the first successful large-scale real world use of RNAi for disease control.     

A comparison of the protein quality of pollens for growth-stimulation of the hypopharyngeal glands and longevity of honey bees,Apis mellifera L. (Hymenoptera: Apidae)

Summary Newly-emerged worker honey bees confined in small cages were fed 33 isonitrogenous diets containing 25 species of pollen. The growth-stimulation of the hypopharyngeal glands was determined by morphological examination after 7 days of feeding. Twenty-two species of pollen were evaluated and compared when they were fed as 10% concentrations of protein, three as 7.5%, six as 5%, two as 2.5%, and one each as 1.25 and 0.625% concentrations.A 0.625% concentration of protein from pollen ofTaraxacum officinale was just as effective in the diet as a 2.5% concentration of protein from pollen ofBaccharis viminea or a 5.0% concentration of protein from pollen ofSorghum. A concentration of 1.25% protein from pollen ofT. officinale in the diet stimulated as much gland growth as either a 7.5% concentration from pollen ofSorghum andB. viminea or a 5.0% concentration of pollen fromZea mays var.saccharata. At a 5.0% concentration of protein, pollen fromRobinia pseudoacacia andPolygonum promoted significantly better development thanRanunculus arvensis andT. officinale fed at the same level. At a 10.0% concentration, pollens fromTrifolium pratense, T. officinale, Prunus serotina, Malus pumila, andPopulus fremonti were significantly better than pollen fromAgoseris, Populus nigra var. italica, orMedicago sativa.Longevity data were obtained for nine species of pollen, six at a concentration of 10% protein, three at 7.5%, four at 5%, and two at 2.5%.

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Résumé Des ouvrières d'abeilles venant de naître et placées dans des cagettes ont reçu 33 alimentations différentes ayant même teneur en azote et renfermant 25 espèces de pollen. Au bout de 7 jours, la rapidité de croissance des glandes hypopharyngiennes a été étudiée par un examen morphologique. On a comparé la valeur de 22 espèces de pollen administrées aux concentrations en protéine suivantes: 10%, 7,5% pour 3 espèces, 5% pour 6 espèces, 2,5% pour 2 espèces, 1,25 et 0,625% pour 1 espèce chacune.Le pollen deTaraxacum officinale, à une concentration en protéine égale à 0,625%, s'est montré aussi efficace que celui deBaccharis viminea à 2,5% ou celui deSorghum à 5,0%. Le pollen deT. officinale, à une concentration en protéine de 1,25%, a eu le même effet stimulant sur la croissance des glandes que celui deSorghum ouB. viminea à 7,5% ou deZea mays var.saccharata à 5,0%. A une concentration en protéine de 5,0%, les pollens deRobinia pseudoacacia et Polygonum ont donné un meilleur résultat queRanunculus arvensis etT. officinale administrés sous la même forme. A la concentration de 10,0%, les pollens deTrifolium pratense, T. officinale, Prunus serotina, Malus pumila etPopulus fremonti étaient nettement plus efficaces que ceux deAgoseris, Populus nigra var.italica ouMedicago sativa. Des données sur la longévité ont été obtenues pour 9 espèces de pollen, 6 à la concentration en protéine de 10%, 3 à 7%, 4 à 5% et 2 à 2,5%.

     

Fine structure and innervation of the honey stomach (crop) of the honeybee,Apis mellifera L. (Hymenoptera : Apidae)

The present paper describes the ultrastructure and innervation of the honey stomach (crop) of Apis mellifera (Hymenoptera : Apidae). The crop is innervated by 10–20 μm-thick nerves with numerous axons, running longitudinally, and small nerves (1–3 μm, often containing only one distinct axon), running latitudinally. Crop muscles are striated, often branched and have only few multidirectionally arranged myofilaments; they seem to be of the slow-contracting type. Longitudinal and circular muscles produce projections that connect synaptically to small nerves. At these neuromuscular junctions, a high density of synaptic vesicles is found in the axons. A small number of apparently multipolar neurones, stained with Procion Yellow, are irregularly distributed over the crop. The possibility that these neurones work as stretch receptor organs is discussed.     

Ultrastructure and ontogeny of the mandibular glands of the queen honey bee,Apis mellifera L. (Hymenoptera: Apidae)

Each mandibular gland of the queen bee, Apis mellifera L. (Hymenoptera: Apidae) consists of an axial cavity lined with a thin cuticular intima, secreted by a flat epithelium, and numerous glandular units (type 3), each unit with one duct cell and a large polyploid glandular cell. Mitochondria and endoplasmic reticulum are preponderant organelles. During the ontogeny of the queen bee, the ultrastructure of the glandular cells evolves as her level of pheromonal activity. Variations mainly concern the mitochondrial system. Hence, at the beginning of the imaginal life, the homogeneous population of small mitochondria increases. Towards the 3rd–5th day of the queen's imaginal life, the pheromonal activity increases and the mitochondrial differentiation results in the appearance of giant forms. During the highest activity phase (6 to 18-month-old queens), giant mitochondria, associated with endoplasmic reticulum, invade cytoplasmic areas. In queens aged from 18 to 24 months, the reduction of pheromonal and secretory activities is associated with the reduction of mitochondrial population as well as with the accumulation of lipid droplets and various lytic structures.     

The indigenous honey bees of Saudi Arabia (Hymenoptera, Apidae, Apis mellifera jemenitica Ruttner): Their natural history and role in beekeeping

Apis mellifera jemenitica Ruttner (= yemenitica auctorum: videEngel 1999) has been used in apiculture throughout the Arabian Peninsula since at least 2000 BC. Existing literature demonstrates that these populations are well adapted for the harsh extremes of the region. Populations of Apis mellifera jemenitica native to Saudi Arabia are far more heat tolerant than the standard races often imported from Europe. Central Saudi Arabia has the highest summer temperatures for the Arabian Peninsula, and it is in this region where only Apis mellifera jemenitica survives, while other subspecies fail to persist. The indigenous race of Saudi Arabia differs from other subspecies in the region in some morphological, biological, and behavioral characteristics. Further taxonomic investigation, as well as molecular studies, is needed in order to confirm whether the Saudi indigenous bee populations represent a race distinct from Apis mellifera jemenitica, or merely an ecotype of this subspecies.     

Effect of entomopathogens on Africanized Apis mellifera L. (Hymenoptera: Apidae)

This study aimed to evaluate the effect of commercially used entomopathogens on Africanized Apis mellifera L. (Hymenoptera: Apidae). Four bioassays were performed: 1) pulverized entomopathogens on A. mellifera; 2) entomopathogens sprayed on a smooth surface; 3) entomopathogens sprayed on soy leaves; and 4) entomopathogens mixed with candy paste (sugar syrup). Five treatments were prepared: sterile distilled water (control), distilled water sterilized with Tween^® 80 (0.01%), and the commercial entomopathogens Metarhizium anisopliae E9 (1.0 × 10⁹ conidia mL^?1), Beauveria bassiana PL63 (1.0 × 10⁸ conidia mL^?1) and Bacillus thuringiensis var. kurstaki HD-1 (3.0 × 10⁸ spores mL^?1). Each treatment consisted of five repetitions, with 20 workers per repetition, which were stored in a plastic box and, later, in a biological oxygen demand (B.O.D.) incubator (27 ± 2 °C, RH of 60% ± 10%, 12-h photophase). The mortality of the workers was evaluated from 1 h to 240 h, and the data were analyzed using Bayesian inference. The workers killed by the ingestion of candy paste contaminated with the pathogens (products) were randomly separated and selected for the removal of the midgut. Each midgut was fixed in Bouin's solution and prepared for histology. B. bassiana was verified to reduce the survival of A. mellifera workers in all bioassays. Moreover, M. anisopliae reduced the survival of A. mellifera workers directly sprayed, on a smooth surface and mixed with candy. B. thuringiensis reduced A. mellifera survival on a smooth surface and mixed with candy paste. However, its effects were lower than that observed by B. bassiana. The treatments with the biological products did not induce morphometric alterations in the midgut of A. mellifera.     

Variation in worker response to honey bee (Apis mellifera L.) queen mandibular pheromone (Hymenoptera: Apidae)

Genetic and environmental influences on the worker honey bee retinue response to queen mandibular gland pheromone (QMP) were investigated. Worker progeny were reared from queens originating from four sources: Australia, New Zealand, and two locations in British Columbia, Canada (Simon Fraser University and Vancouver Island). Progeny from New Zealand queens responded significantly higher (P < 0.05) than progeny from Australia in a QMP retinue bioassay. Retinue response was not related to queen production of pheromone or colony environment, and the strain-dependent differences in retinue bioassay responses were maintained over a wide range of dosages. Selected high- and low-responding colonies were bioassayed over the course of 1 year. High-responding colonies contacted QMP lures more frequently than low-responding colonies (P < 0.05) throughout the year except in late summer. We conclude that there is a strong genetic component to QMP response by worker honey bees, as well as a seasonal effect on response.     

Kinetic properties of arginine phosphokinase from honeybees, Apis mellifera L. (Hymenoptera, Apidae)

The kinetic properties of honeybee arginine phosphokinase (APK), which catalyzes the reaction: Arginine phosphate + ADP + H⁺ ? arginine + ATP, have been studied.In the direction of ATP synthesis, the pH optimum was around pH 7.2 and the activation energy over the range 18–44 °C was about 10,500 cal/mole. The optimum ratio of Mg²⁺:ADP was about 4:1.In the direction of arginine phosphate (AP) synthesis, the enzyme had a pH optimum around pH 8.3. The energy of activation for the reaction over the range 22–39 °C was about 7500 cal/mole. The optimum ratio of Mg²⁺:ATP was about 1:1.The initial velocities of the reactions in the direction of ATP and AP synthesis were measured at varying concentrations of one substrate while the concentration of the other substrate was held constant at several levels. The double reciprocal plots of the data obtained yielded a series of intersecting lines, indicating that the enzyme has a sequential mechanism. Radioisotope exchange experiment showed that arginine phosphokinase did not catalyze ATP ? ADP exchange in the absence of arginine. Product inhibition studies showed that arginine was competitive with AP and noncompetitive with ADP; whereas ATP was competitive with ADP and noncompetitive with arginine. The results from initial velocity, radioisotope exchange, and product inhibition studies suggested that the enzyme has a rapid equilibrium, random mechanism.