Effect of topical application of juvenile hormone (JH) in honeybee worker larvae on the development of the Dufour's and Koschewnikow's glands

In order to investigate the action of the juvenile hormone (JH) on honeybee caste differentiation two exocrine glands, Koschewnikow and Dufour glands, were chosen for study. Two combs (I & II) were taken from a single posture of a queen to use for this research. In comb I the larvae were treated with a topical application of JH in Acetone, and those from the comb II (control group) received only Acetone. Immediately after the emergence of the workers, their glands were dissected and prepared for microscopic measurements. The results showed cell area reduction in the Koschewnikow gland induced by the JH application. The results for the Dufour gland displayed taller epithelial cells with the JH application. The difference in glandular responses to the JH relates to gland function, hormone targets, and individual homeostasis.

Morphological and biochemical analysis of the stored and larval food of an obligate necrophagous bee, Trigona hypogea

Trigona hypogea, T. crassipes, and T. necrophaga are obligate necrophagous bees that differ from the majority of bees by using animal material instead of pollen as a protein resource. Since T. hypogea does not store protein in cerumen pots, it was thought that glandular secretions were its only larval protein source. This is in contrast to T. necrophaga which stores a yellowish proteinaceous jelly in the pots. Our results show that the larval food of T. hypogea has a higher protein content than the food stored in the pots and that it presents an electrophoretical protein pattern similar to that of the hypopharyngeal gland, indicating that workers add glandular secretions to the larval food while provisioning the brood cells. Thus, it can be suggested that T. hypogea has a provisioning behavior similar to other Meliponinae. The presence of several bands of proteins in the food stored in the pots shows that this species stores carrion mixed with honey in storage pots. Morphological data suggest that both larvae and adults make use of the same foodstuffs. These results also suggest that T. hypogea is more similar to other necrophagous species than it is to T. necrophaga (a more specialized bee).

Morphophysiological Differences between the Metapleural Glands of Fungus-Growing and Non-Fungus-Growing Ants (Hymenoptera, Formicidae)

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

Morphologic and morphometric aspects of oenocytes of Apis mellifera queens and workers in different phases of life

Oenocytes of adult workers and queens of Apis mellifera L. were studied in different ages or life stages, by means of morphometric and histologic techniques. In workers, the oenocytes were found in the head, near the mandibles and in the abdomen, immersed in the parietal fat body mainly below the sterna, close to the wax gland. In queens, two populations of oenocytes different in size and localization were found within the parietal and visceral fat body, respectively. The oenocytes of workers and queens show the presence of acid lipids and acid phosphatase. The role of these cells in the castes differences is discussed.