RESUMO As glândulas exócrinas desempenham importantes funções na organização social dos insetos, como a diferenciação de castas e inter-castas. Devido à sua plasticidade estrutural e funcional, estudos morfológicos destas glândulas contribuem para o melhor entendimento da biologia das abelhas sociais. Por isso, o objetivo deste estudo foi acompanhar o desenvolvimento pós-embrionário das glândulas intramandibulares de operárias da abelha sem ferrão Friesella schrottkyi (Friese, 1900) (Hymenoptera: Apidae) com análises histológicas e histoquímicas. As mandíbulas das pupas em diferentes estágios do desenvolvimento e operárias recém-emergidas foram analisadas. As glândulas intramandibulares de F. schrottkyi são divididas em dois tipos: glândulas da classe I na epiderme da mandíbula e da classe III, inseridas na cavidade da mandíbula que se abrem na superfície externa. As glândulas intramandibulares de F. schrottkyi se desenvolvem durante a transição de pré-pupa para pupa de olho branco como observado pelas alterações morfológicas nas células. As pupas de olhos pretos de F. schrottkyi apresentaram glândulas intramandibulares completamente desenvolvidas.

ABSTRACT Exocrine glands play important role in social organization of insects, such as caste and inter-caste differentiation. Due their functional and structural plasticity, morphological studies on such glands contribute to better understanding the biology of social bees. Therefore, the aim of the study was to characterize the sequence of the post-embryonic development of intramandibular glands of Friesella schrottkyi (Friese, 1900) (Hymenoptera: Apidae) workers using histological and histochemical analyses. The mandibles of pupae at different developmental stages and newly emerged adults were analyzed. The intramandibular glands of F. schrottkyi presented two types: class I glands, in the mandible epidermis and class III glands, inside the mandible cavity that open onto external surface. The intramandibular glands of F. schrottkyi developed during the transition from the prepupae to the white-eyed pupae, as shown by the morphological changes. Black-eyed pupae of F. schrottkyi presented fully developed intramandibular glands.

Collection data of Euglossinae males from Parque Estadual do Rio Doce (PERD) and Viçosa, both areas with remnants of Atlantic Rain Forest (Mata Atlântica) in Minas Gerais state, Brazil are presented. Comparisons made among three fragments with different sizes and states of disturbance from Viçosa showed differences in abundance of most common species and apparently, Eulaema nigrita Lepeletir, 1841 can be an useful indicator of disturbed sites. Some populations of euglossine bees seems to be restrict to a forest fragment, there being few or no flow of individuals or species of one fragment to another, even when they are only 1 km apart. 15 species of euglossines were sampled in PERD, and the most abundant was Eulaema cingulata (Fabricius, 1804). At Viçosa, 10 species were sampled, E. nigrita was the predominant one. Methyl salicylate attracted no males at both sites, in spite of large numbers of species and individuals sampled using this bait in other regions. The majority of species and individuals were collected in the rainy season. Only 0,58% of sampled males carried orchid pollinia (Catasetum Richard, Cycnoches Lindley and Coryanthes Hook) on their bodies. Emergence data of four species of Euglossa Latreille, 1802 reared from trap nests suggest that sex ratio in Euglossini is not a constant within the tribe. A list of 57 euglossine species now known to occur in Mata Atlântica are offered.