-The objectives of this work were to determine the squash entomofauna in the region of Viçosa, Minas Gerais state, to study their behavior on fl owers and their importance for pollination, verifying the role of each pollinator. The most common species were Trigona spinipes (Fabricius), Trigona hyalinata (Lepeletier), Apis mellifera (L.) and Melipona quadrifasciata (Lepeletier). The visitation behavior of A. mellifera, M. quadrifasciata, and Bombus morio (Swederus) were similar. They visited fl owers for nectar collection, positioning themselves vertically between the corolla and the sexual structures of the fl owers, with the back directed toward the fl oral axis, which permitted the removal of pollen from the anthers of fl owers with stamens and its deposition on the stigma of fl owers with pistils, being considered therefore effective pollinators. Trigona spinipes and T. hyalinata foraged in groups, preventing other species from landing on the fl owers which they occupied. Due to their small body size and only infrequent contact with the sexual structures of the fl owers, these species are considered occasional pollinators. The number of fruits produced differed between freely visited fl owers, those prevented from receiving visits and those visited only a single time by M. quadrifasciata, B. morio, A. mellifera, T. hyalinata or T. spinipes. Flowers prevented from receiving visits or visited only once by T. spinipes did not produce fruits. The remaining pollination systems led to fruitifi cation, with open pollination or a single visit from either M. quadrifasciata or B. morio leading to most fruit production.

Mountain endemic species are usually related to a restricted set of ecological conditions, presenting a fragmented range interspersed by lowland that may prevent its dispersion and favors isolation and speciation. Here we investigate the pattern of distribution of Melipona capixaba, an endemic bee species of mountain areas of central Atlantic forest by means of species distribution modeling procedures. We aimed to describe the potential distribution of this species considering broad climatic variables and evaluate the possible non-equilibrium of its range using models that simulate restricted dispersion by inclusion of spatial variables. The models indicate that the known occurrence points are located in a small fraction of its potential distribution, which is fragmented in different mountain ridges. Models without spatial variables predicted a larger range and an overlap with the distribution of a closely related species, M. scutellaris. Ensemble models also indicate areas to future search for new population of this species, as well as important areas for its conservation.

ABSTRACT. Abundance, spatial distribution of Meliponina bees' nests (Hymenoptera, Apidae, Apini) and plant species used as nesting sites in savanna areas of Maranhão, Brazil. This study aimed at identifying the stingless bees species (Hymenoptera: Apidae, Apini, Meliponina) those were found in three study sites of cerrado, northeastern Brazil. The study also aimed identifying the plant species those were used as nesting sites by the stingless bees and verifying their characteristics. We intended to verify abundance and spatial distribution of the nests and patterns of the plants used as nesting sites. Seventy-three nests of 15 species were found. The most abundant species were Partamona chapadicola Pedro & Camargo, 2003 (34,25%) and Oxytrigona sp. 2 (20,55%). Eleven tree species were used as nesting sites. The most common host tree species was Qualea parviflora (Vochysiaceae) where 38,36% of the nests (n=28) nestled, followed by Salvertia convallariodora (Vochysiaceae) (n=17, 23,29%). The 95% confidence interval of DHB was between 36,21 cm and 41,68 cm. This interval is related with older trees that should have more hollows to be used as nesting sites. This process might be occurring with S. convallariodora and Q. parviflora. The patterns of spatial distribution for study sites 1 and 2 were random and the pattern for study site 3 was uniform. Random pattern would be a sign for absence of competition. On the other hand uniform pattern would indicate competition. KEYWORDS.Meliponina, fragmentation, Cerrado, nesting sites, spatial distribution. RESUMO.O trabalho objetivou identificar as espécies de abelhas sem ferrão (Hymenoptera, Apidae, Apini, Meliponina) presentes em três áreas de cerrado no Maranhão, nordeste do Brasil, por meio do levantamento de seus ninhos. Também foi objetivo do trabalho identificar e caracterizar os substratos vegetais utilizados como locais de nidificação. Pretendeu-se averiguar a abundância e a distribuição espacial de ninhos, bem como padrões de uso dos substratos para nidificação. Foram encontrados 73 ninhos pertencentes a 15 espécies. As espécies mais abundantes foram Partamona chapadicola Pedro & Camargo, 2003 (34,25%) e Oxytrigona sp. 2 (20,55%). Identificaramse 11 espécies vegetais utilizadas para construção dos ninhos. O substrato de nidificação mais freqüente foi Qualea parviflora (Vochysiaceae), na qual encontrou-se 38,36% do total de ninhos (n=28), seguido por Salvertia convallariodora (Vochysiaceae) (n=17; 23,29%). O intervalo de confiança de 95% para o DAP situou-se entre 36,21 cm a 41,68 cm. Este intervalo representaria árvores mais velhas que teriam mais cavidades disponíveis para nidificação, o que poderia ser o caso de S. convallariodora e Q. parviflora. O padrão de dispersão dos substratos com ninhos mostrou-se aleatório nas áreas 1 e 2 e uniforme na área 3. Padrões de distribuição aleatórios seriam um indício da ausência de competição e padrões uniformes indicariam competição. PALAVRAS-CHAVE.Meliponina, fragmentação, cerrado, substratos de nidificação, distribuição es...

Pollen types present in samples from corbiculae of Melipona capixaba (Moure and Camargo) (Hymenoptera: Apidae: Meliponina) worker bees were analyzed, as well as pollen samples from food pots inside the hives in three sites located at the bees’ original habitat. The aim was to find out the sources used as a trophic resource by this species. The dominant pollen grains in the spectrum of the samples belonged to the families Myrtaceae and Melastomataceae. Eucalyptus was the most frequent pollen type in the corbiculae in Conceição do Castelo municipality; Eucalyptus, Myrcia, and Melastomatacea/Combretaceae in the Fazenda do Estado district; and Eucalyptus and Myrcia in the São Paulo de Aracê district, both in the Domingos Martins municipality. Eucalyptus and Melastomataceae/Combretaceae were the predominant pollen types in the food pots. Eucalyptus was the most prevalent type all year round or most of the year. The most common pollen types in the months that Eucalyptus was not present or dominant in the samples were of remaining native forest species, “ruderal” (field) plants, fruit-bearing plants, and introduced ornamental plants.