Chemical composition of the dufour gland secretion in queens of Melipona bicolor (Hymenoptera, Meliponini)

We describe differences in the chemical composition of the Dufour gland secretion of virgin and physogastric queens of Melipona bicolor through gas chromatography and mass spectrometry. The Dufour gland secretion of virgin queens consists only of hydrocarbons, while that of physogastric queens contains, besides these, a variety of other compounds, such as isobutyrate and acetate esters. Such differences may indicate the queen fecundity condition and the oxygenated compounds of the physogastrics secretion may help to increase their attractiveness.

Investigation of Partamona helleri (Apidae, Meliponini) B chromosome origin. An approach by microdissection and whole chromosome painting

The stingless bee Partamona helleri in southeast Brazil shows the regular chromosome number 2n = 34 and a variable number of up to four minute B1 or B2 chromosomes. Previous cytogenetic analyses have indicated morphological similarities between the B1 chromosome and chromosome segments in the regular karyotype. In this study, microdissection and chromosome painting were employed along with C banding, NOR banding, and base-specific fluorochrome staining to investigate the origin of the B1 chromosome in P. helleri. B1-generated probe hybridized exclusively to B1 chromosomes. This result suggests an independent origin from the regular karyotype or, alternatively, that the B chromosome may have suffered substantial genetic alterations along its independent evolution. The absence of higher dosages of these small B chromosomes in this population of P. helleri may be related to the existence of either a genetic or cytogenetic constraint in the establishment of such high numbered karyotypes. © 2012 INRA, DIB and Springer-Verlag, France.

Cellular responses in the Malpighian tubules of Scaptotrigona postica (Latreille, 1807) exposed to low doses of fipronil and boric acid

Studies of sub-lethal effects of pesticide residues on stingless bees are scarce and morphological analysis of organs would add information to toxicological analysis in order to clarify the continuous exposure of Scaptotrigona postica to insecticides. The aim of this study was to evaluate the morphology and histochemistry of the Malpighian tubules (excretory organ) of S. postica exposed to fipronil or boric acid to detect cellular responses that indicate toxicity or adaptative mechanisms to stress induced by exposure of worker bees to low doses of these chemical compounds. Newly emerged bees were submitted to toxicological bioassays and morphological analyses by optical microscopy and Transmission Electron Microscopy, as well as histochemical methods, were performed to detect proteins and glycoconjugates. Additionally, immunohistochemical detection of DNA fragmentation and HSP70 (70-kDa Heat shock protein) were performed to detect cell death and stress response, respectively. Statistical analysis, for the bioassays conducted with ingestion of contaminated diet with boric acid at 0.75% (w/w) or with fipronil at 0.1μg/kg of food, showed that the survival of bees that ingested the contaminated diets were significantly different to the survival rate presented by the control group (P<0.0001). Although some characteristics indicative of initiation of cell death were observed, the cells remained metabolically active in the processes of excretion and inactivation of chemical compounds. The data from this study reinforce the importance of research on sublethal effects of low doses of pesticides on bees in an attempt to assess a possible realistic dose and evaluate the risk assessment of stingless bee S. postica foraging in the vicinity of cultivated fields and/or in green urban areas. © 2013 Elsevier Ltd.

Avaliação dos efeitos do inseticida imidacloprido para abelhas sem ferrão Scaptotrigona postica Latreille, 1807 (Hymenoptera, Apidae, Meliponini): Hellen Maria Soares. -

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos do inseticida fipronil sobre os corpos pedunculados de operárias de Scaptotrigona postica (Hymenoptera, Apidae, Meliponini)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relação entre o corpo gorduroso e a vitelogênese em fêmeas de Melipona quadrifasciata anthidioides Lep

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Características florais e dependência por polinizadores de cinco cultivares de pepino e manejo de colméias em estufas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Separation of Scaptotrigona postica Workers into Defined Task Groups by the Chemical Profile on Their Epicuticle Wax Layer

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Africanized honey bee (Apis mellifera) venom profiling: Seasonal variation of melittin and phospholipase A(2) levels

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Behavioral responses evoked in honey bee workers by Dufour gland extracts (Hymenoptera : Apidae)

A series of experiments was performed to assess possible roles of the honey bee Dufour gland secretion. Bioassays with extracts of queen and worker glands from two colonies were made under artificial conditions, in which nestmate and non-nestmate forager workers were tested. The results demonstrate that forager workers display behavioral responses when exposed to Dufour gland extracts of nestmates, but remain indifferent when exposed to non-nestmate extracts. Also, the results demonstrate that forager workers are attracted by virgin queen gland extracts, and repelled by forager worker extracts. The data demonstrate that the Dufour gland secretion is colony- and caste-specific. The attractant remains in the nest. The repellent effect of forager worker extracts is interpreted as an alarm-like pheromone. The attractant effect of virgin queen extracts could be useful in the swarming process to attract scout bees to the eventual founder virgin queen or to attract old foragers to the virgin queen that remains in the nest.

Modes of cell death in the hypopharyngeal gland of the honey bee (Apis mellifera L)

Different modes of cell death have been revealed in the regressing hypopharyngeal glands of worker honey bees. The hypopharyngeal gland, which is well developed in young nursing bees to produce protein for larval food, was seen to regress naturally in foraging adult worker bees. A range of techniques including histology, cytochemistry, in situ TUNEL, Annexin V and Comet assays indicated that cells within the gland demonstrate progressive symptoms of apoptosis, necrosis and a vacuolar form of programmed cell death. The latter mode of cell death did not display chromatin margination, but was accompanied by an enhanced level of autophagic and hydrolytic activity in which a cytosolic source of acid phosphatase became manifest in the extra-cisternal spaces. Normal and annexin-positive cells were found to occur in the younger nursing bees, whilst necrosis and an aberrant vacuolar type of apoptosis predominated in the older foraging bees. The relevance of these results to the classification of programmed cell death is discussed. (C) 2000 Academic Press.

Differences in the number of some antennal sensilla of four honey bee (Apis mellifera) types and comparisons with the defensive behaviour

The number of sensilla coeloconica, ampullacea and campaniformia of flagellomeres 3 to 10 of the antennae of workers of four honey bee types (Italian, Caucasian, African and Africanized) was studied by scanning electron microscopy. Comparisons of the four bee types showed that only African and Africanized honey bees did not differ from one another with respect to the number of sensilla coeloconica and ampullacea of flagellomere 10. African and Africanized honey bees and Caucasian and Italian honey bees also did not differ from one another in terms of flagellomere 9. In the other flagellomeres there were no differences among bee types. Italian and Caucasian honey bees differed from Africanized honey bees in terms of number of sensilla campaniformia on flagellomere 6, and Caucasian honey bees differed from African and Africanized honey bees in terms of flagellomere 3. Five significant but random correlation values were obtained between number of antennal sensilla and defensive behaviour in Africanized honey bees. Thus,there is no relationship between antennal structures and defence behaviour.

Morphological characterization of cell death during the ovary differentiation in worker honey bee

Cell death that occurs during ovary differentiation in the honeybee worker's larval development accounts for ovariole reabsorption. From a morphological standpoint, three modes of death were detected. Germinative cells in the ovarioles die by an apoptotic-like process, whereas the somatic cells die by an autophagic process, type 11 cell death; and during pupation, stromatic and ovarian capsular cells die through cytoplasmic disintegration, releasing their components into the hemolymph. These modes of cell death are in part determined by the pattern of tissue organization within which the cell occurs. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Biochemical and cytochemical studies of the enzymatic activity of the venom glands of workers of honey bee Apis mellifera L. (Hymenoptera, Apidae)

Biochemical studies revealed that the activity of some hydrolytic enzymes from the venom glands of honey bee Apis mellifera was higher in workers of 14 days of age than in those of 40 days. Among these enzymes, the highest activity was recorded for acid phosphatase, which was cytochemically detected throughout the length of the secretory filament and surrounding the canaliculi of the distal region of the reservoir. The acid phosphatase was considered to be a typical secretion product, since it was present in the cytoplasm as well as in the canaliculi of the secretory cells. (c) 2009 Elsevier Ltd. All rights reserved.