Ultrastructural and Cytochemical Aspects of Metamorphosis in the Midgut of Apis mellifera L. (Hymenoptera: Apidae: Apinae)

The midgut of Apis mellifera is remodeled during metamorphosis. The epithelium and, to a lesser extent, the muscular sheath degenerate between the end of the last larval instar and the onset of pupation (prepupa).The larval epithelium is shed to the midgut lumen and digested, while a new epithelium is reconstructed from larval regenerative cells. During pupation, some reorganization still occurs, mainly in brown-eyed pupae. In pharate adult, the midgut wall shows the characteristics of adult, although some cells have pycnotic nuclei. The localization of alkaline and acid phosphatases showed that these enzymes were not involved in the reabsorption of the midgut wall.

Eficiência de extratos de plantas medicinais e aromáticas em atrair a abelha africanizada (Apis mellifera L.) em cultura de abacateiro (Persea americana Mili.)

The objective of the experiment was to test attractive substances for Africanized honey bees, Apis mellifera L., in avocado, Persea americana Mill. Were pulverized extracts of lemon grass (Cympobogon citratus), ocimum (Ocimum sellowii), Lippia alba, orange leaves (Citrus sinensis), eucaliptus leaves (Eucalyptus sp), eugenol and linalol and the frequency of bees on flowers were evaluated. The frequency of honey bees did increase with the application of the extracts falsa melissa, eucaliptus leaves and orange leaves, used as attractants in Quintal variety. The products tested in Eppendorf tubes did not increased the frequency the bees in Quintal and Fortuna varieties.

Apis mellifera (Hymenoptera, Apini) Ovary Development in Queens and in Workers from Queenright and Queenless Colonies

A morphological study of the development of the ovaries in workers from queenright and queenless colonies and queens of Apis mellifera is presented and discussed. The mating stimulates the ovary development and the egg-laying. Mating prevention or egg laying prevention provokes reabsorption in the queens ovaries, characteristic of the queen stage or ovariole development. Ovary development was observed in queenless and in queenright colonies but the queen's presence, the worker's age and the type of tasks done by them interfere with their development.

Electrophoretical Protein Profile in Apis mellifera (Hymenoptera; Apidae) Hypopharyngeal Glands under Juvenile Hormone Effect When the Colony is Grown in the Absence of Brood

Twelve-day-old and 25-day-old Apis mellifera workers were treated or not treated with juvenile hormone at the moment of emergence and reared in the colony without brood. Having the brood interference apart, the hormone effect on the hypopharyngeal glands protein expression was determined through the electrophoretical protein profiles of the both groups of bees. In those conditions, the hormone induced changes that were different from the control. Protein bands of 66 and 48 kDa were intensified in the 12-day-old bees, whereas band of 42 kDa was reduced in the 25-day-old bees. That indicated a different effect of the juvenile hormone in the function of bee aging, which promoted a glandular protein activation in the young bees and, in contrast, an inhibitory action in the 25-day-old bees workers.

Juvenile Hormone Effect on the Venom Gland Secretory Cycle in Workers of Apis mellifera (Hymenoptera, Apidae)

The present investigation analyzed the influence of Juvenile Hormone (JH) on the venom glands of Apis mellifera workers through protein dosage and electrophoresis of venom gland extracts of newly emerged workers which were treated with 1 μl JH dissolved in hexane, in concentration of 2μg/μl. Newly emerged workers non-treated and treated with 1 μl hexane were the controls. Both JH and hexane provoke quantitative changes on the gland protein titre and on the protein electrophoretic profile. The disappearance of protein bands in the venom gland extracts of 14 day-old treated workers, a situation normally found only in 35 day-old non-treated workers, suggests that the JH treatment induces a precocious maturation of the worker venom gland.

Atividade anti Staphylococcus aureus de extratos de própolis (EP) de Apis mellifera preparados com diferentes concentrações de etanol

Propolis has been used in folk medicine and possesses a broad spectrum of biological activities, specially antibacterial activity. Studies have demonstrated that the composition of propolis extract may have influence in such activity. The goal of this study was to investigate the antibacterial activity of eleven propolis extracts (PE) against sixty one Staphylococcus aureus strains, isolated from newborn clinical specimens. The PE from Apis mellifera were prepared by using pure water and mixtures of water with ethanol at different concentrations (from 0 to 100%), 25g of propolis in 100 mL of solvent, and three days of maceration followed by filtration. Determination of Minimal Inhibitory Concentration (MIC) by agar dilution method was performed and serial concentrations from each PE were achieved (%v/v) in plates containing Mueller Hinton agar. It was possible to verify that the anti S. aureus activity was directly proportional to ethanol concentration and no significant differences were observed among PE with ethanol concentration from 70 to 100%. The MIC 90% values ranged from 0.4 to 0.6% (v/v) and the 70% ethanolic extract were the most efficient to inhibit bacterial growth (MIC 90%=0.42%, v/v). In conclusion, our results suggest that the EP composition and, consequently, the concentration of ethanol used as solvent may influence the antibacterial activity of propolis from A. mellifera.

Ultramorphology and histology of the venom gland of workers of Apis mellifera (Hymenoptera, Apidae) before and after an electrical shock treatment

This paper describes the ultramorphology and histology of the venom reservoir in 14-day old workers of Apis mellifera, immediately before and after the application of electrical shocks with the object of causing venom elimination and reservoir collapse. The external epithelial surface of the reservoir was differentiated according to its morphological aspects into posterior, median, and proximal or duct regions at the ventral surface and into anterior and posterior regions at the dorsal surface. While the epithelium of the proximal region forms a ventral infolding, a dorsal salience is formed at this region. These structures and the epithelial regions persist both in full and empty reservoirs. The reservoir appeared full and distended before the electrical shocks were applied and became empty and withered afterwards due to the elimination of the secretion, without any reductions in length. Nevertheless, some secretion was kept inside the lumen, thus suggesting a possible role for the reservoir in the modification of the secretion.

Hydrolases in the hypopharyngeal glands of workers of Scaptotrigona postica and Apis mellifera (Hymenoptera, Apinae)

Hydrolytic enzymes from hypopharyngeal gland extracts of newly emerged, nurse and foraging workers of two eusocial bees, Scaptotrigona postica, a native Brazilian stingless bee, and the Africanized honey bee (Apis mellifera) in Brazil, were compared. The hypopharyngeal gland is rich in enzymes in both species. Fifteen different enzymes were found in the extracts, with only a few quantitative differences between the species. Some of the enzymes present in the extracts may have intracellular functions, while others seem to be digestive enzymes. Scaptotrigona postica, had lower β-glucosidase and higher lipase esterase activities than A. mellifera. The differences may be due to different feeding habits and behavioral peculiarities of the two species. ©FUNPEC-RP.

Effect of mating delay in the ovary of Apis mellifera L. (Hymenoptera, Apidae) queens: Histological aspects

This paper reports the effect of mating delay on the queen Apis mellifera ovaries based on a light microscopy analysis. Soon after a queen emerges from the brood cell, oocytes start to differentiate in the ovaries, but if mating does not occur at the correct age (about 6 days after emergence) cell degeneration begins. Ovaries of 15-day-old virgin queens show extensive disorganization with cell death affecting all types of ovariole cells. Types of cell death and the possible causes are discussed.

Produtos naturais no comportamento defensivo de Apis mellifera L.

The goal was to investigate the influence of natural products such as lemongrass (Cymbopogon citratus), dried avocado leaves (Persea americana), coffee husk (Coffea arabica) and castor bean (Ricinus communis) in the defense of Apis mellifera, as well the effect of these products on the population development of the beehive. Defensive behavior was evaluated by time of first sting (TFS) and number of stingers (NS), and population development, by open brood area and operculated brood. It was observed that the treatment with smoke + seven castor beans presented significant increase in the TFS, for treatment without and with smoke. Regarding NS, it was verified that the treatments with smoke + seven castor bean and smoke + 20% coffee husk were different from the treatment without and with smoke. The other treatments did not differ significantly with respect to the use of smoke or its absence. The application of coffee husk and castor bean did not interfere in the development of the population, suggesting that these compounds were not toxic. It can be concluded that the use of castor bean and coffee husk in smoke may represent an important tool for the reduction of defensiveness, without promoting toxicity for A. mellifera.

Brain morphophysiology of Africanized bee Apis mellifera exposed to sublethal doses of imidacloprid

Several synthetic substances are used in agricultural areas to combat insect pests; however, the indiscriminate use of these products may affect nontarget insects, such as bees. In Brazil, one of the most widely used insecticides is imidacloprid, which targets the nervous system of insects. Therefore, the aim of this study was to evaluate the effects of chronic exposure to sublethal doses of imidacloprid on the brain of the Africanized Apis mellifera. The organs of both control bees and bees exposed to insecticide were subjected to morphological, histochemical and immunocytochemical analysis after exposure to imidacloprid, respectively, for 1, 3, 5, 7, and 10 days. In mushroom bodies of bees exposed to imidacloprid concentrations of LD50/10 and in optic lobes of bees exposed to imidacloprid concentrations of LD 50/10, LD50/100, and LD50/50, we observed the presence of condensed cells. The Feulgen reaction revealed the presence of some cells with pyknotic nuclei, whereas Xylidine Ponceau stain revealed strongly stained cells. These characteristics can indicate the occurrence of cell death. Furthermore, cells in mushroom bodies of bees exposed to imidacloprid concentrations of LD50/10 appeared to be swollen. Cell death was confirmed by immunocytochemical technique. Therefore, it was concluded that sublethal doses of imidacloprid have cytotoxic effects on exposed bee brains and that optic lobes are more sensitive to the insecticide than other regions of the brain. © 2013 Springer Science+Business Media New York.

Efeitos das doses subletais de fipronil para abelhas africanizadas (Apis mellifera L.), por meio de análises morfológicas e comportamentais

Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC

Porcentagem de aceitação de larvas de diferentes grupos genéticos de Apis mellifera na produção de abelhas rainhas

Pós-graduação em Zootecnia - FMVZ

Diferentes manejos na produção de mel em abelhas Apis mellifera L. e seu efeito na expressão de genes relacionados ao estresse

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Produção de apitoxina por abelhas Apis mellifera L. e seu efeito na expressão de genes relacionados ao estresse

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)