Morphology and Morphometry of the Midgut in the Stingless Bee Friesella schrottkyi (Hymenoptera: Apidae)

Friesella schrottkyi is a small stingless bee (3-mm long) important for agricultural and native forest pollination. This study describes the morphology and morphometry of the midgut in F. schrottkyi forager workers. The F. schrottkyi midgut presents a single-layered epithelium with digestive, regenerative and endocrine cells. The digestive cells are similar along the entire midgut length with a spherical nucleus, apex with long striated border, cytoplasmic granules in the apical region and well-developed basal labyrinth associated with mitochondria, suggesting they are multifunctional, synthesizing digestive enzymes and peritrophic matrix compounds and absorbing nutrients. Regenerative cells are located around the basal region organized in nests with some cells with a spherical nucleus. Phe-Met-Arg-Phe-NH2-amide (FMRFamide) positive endocrine cells are restricted to the posterior midgut region, suggesting a paracrine function in the midgut. This is the first morphological description of the F. schrottkyi midgut contributing to the comprehension of the digestive process of this bee.

Post-embryonic development of intramandibular glands of Friesella schrottkyi (Friese, 1900) (Hymenoptera: Apidae) workers

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.

Onde os mais Adaptados Permanecem: Comunidade de Abelhas sem Ferrão (Hymenoptera: Apidae, Meliponini) em Áreas Urbanas do Município de Ubá, Minas Gerais, Brasil

A urbanização tem causado a fragmentação de vários ambientes naturais, levando à perda de muitos processos ecológicos como a polinização, realizada principalmente por abelhas, em especial as espécies de Meliponini, que tem reduzido drasticamente as suas populações devido à perda de habitat pela expansão urbana. O objetivo deste estudo foi realizar um levantamento das espécies de abelhas sem ferrão em áreas urbanas do município de Ubá - MG, Brasil, relacionar a riqueza e abundância das espécies encontradas com a taxa de ocupação das variáveis estruturais da paisagem das áreas urbana e relacionar a presença das espécies obtidos com estas variáveis. Foram encontrados 28 ninhos pertencentes a quatro espécies, Tetragonisca angustula (Latreille), Trigona spinipes (Fabricius), Nannotrigona testaceicornis (Lepeletier) e Friesella schrottkyi (Friese). Não houve relação significativa entre a riqueza e abundância de Meliponini e variáveis estruturais de vegetação analisadas, possivelmente devido a valores baixos no número de ninhos e espécies encontrados. Somente T. spinipes se mostrou relacionada com a presença de vegetação. Os resultados mostram que a comunidade Meliponini é composta por espécies generalistas capazes de utilizar cavidades artificiais e plantas ornamentais como uma fonte alternativa de recursos, comuns em áreas urbanas. Os resultados obtidos neste estudo servem de alerta para atuais condições dos remanescentes vegetais em áreas urbanas na cidade de Ubá, além de também poderem ser usados como material de apoio na tomada de decisão sobre projetos de conservação e recuperação de áreas degradadas, tendo como foco sobre as abelhas e sua importância para a sustentabilidade destes ecossistemas.Where the most Adapted Remain: Stingless Bees Community (Hymenoptera: Apidae, Meliponini) in Urban Areas of the City of Uba, Minas Gerais, Brazil Abstract. The urbanization has caused the fragmentation of various natural environments, taking to loss of many ecological processes in which includes pollination, realized mainly by bees, in special Meliponini species, which has drastically reduced their populations due to loss of habitat for urban expansion. The aim of this study was to survey the species of stingless bees in urban areas of the municipality of Ubá - MG, Brazil, relate the richness and abundance of species found with the percentage of occupation of the structural variables of the urban landscape and relate the presence of the species obtained with these variables. Were found 28 nests belonging to four species, Tetragonisca angustula (Latreille), Trigona spinipes (Fabricius), Nannotrigona testaceicornis (Lepeletier) and Friesella schrottkyi (Friese). There was no significant relationship between richness and abundance of Meliponini and structural variables of vegetation, possibly due to low values in the number of nests and species obtained. Only T. spinipes showed related to the presence of vegetation. The results show that the Meliponini community is composed by generalist species able to use artificial cavities and ornamental plants as an alternative source of resources, common in urban areas. The results obtained in this study is a warning to current conditions of the plant remaining in urban areas in the city of Ubá, besides may also be used as support in taking-decision on projects for the conservation and recovery of degraded areas, focusing on bees and their importance to the sustainability of these ecosystems.

Abelhas sem ferrão (Hymenoptera: Apidae, Meliponini) da Estação Ecológica de Água Limpa, Cataguases-MG, Brasil.

Resumo. No presente estudo realizou-se um levantamento de ninhos de abelhas Meliponini na Estação Ecológica de Água Limpa (EEAL), no município de Cataguases, Minas Gerais. Foram encontrados 21 ninhos pertencentes a nove espécies: Friesella schrottkyi (Friese), Melipona bicolor Lepeletier, Plebeia sp. 1, Plebeia sp. 2, Tetragona clavipes (Fabricius), Tetragona quadrangula (Fabricius), Tetragonisca angustula (Latreille), Trigona hyalinata (Lepeletier), Trigona spinipes (Fabricius). Vinte dos 21 ninhos foram encontrados em substrato arbóreo. A fauna de Meliponini observada na EEAL é representada por um baixo número de espécies. Embora a vegetação local tenha potencial para oferecer substratos para nidificação e recursos florais, a baixa riqueza de espécies pode estar relacionada com o fato da EEAL ser um remanescente florestal isolado. Stingless Bees of the Estação Ecológica de Água Limpa, Cataguases-MG, Brazil Abstract. This study carried out a survey of nests of stingless bees present in the Estação Ecológica de Água Limpa (EEAL) in the municipality of Cataguases, Minas Gerais. We found twenty-one nests belonging to nine species: Friesella schrottkyi (Friese), Melipona bicolor Lepeletier, Plebeia sp. 1, Plebeia sp. 2, Tetragona clavipes (Fabricius), Tetragona quadrangula (Fabricius), Tetragonisca angustula (Latreille), Trigona hyalinata (Lepeletier), Trigona spinipes (Fabricius). Twenty of the 21 nests were found in arboreal substrate. The fauna of stingless bees observed in EEAL is represented by a low number of species. Although the local vegetation has the potential to provide substrates for nesting and floral resources, the low species richness may be related to the fact that the EEAL is an isolated forest remnant.