ABSTRACT. Eugl ossine bees (Apidae) frem Atlantic Forest sites: abundance, richness, and bi ological aspects. Co llection data of Euglossinae males from Parque Estadual do Rio Doce (PERD) and Viçosa, both areas w ith 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 di sturbance fi'om Viçosa showed difterences in abundance of most common spec ies and apparently, Eu/aema 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 tlow of individuais OI' species of one fi'agment to another, even when they are only I km apal1. 15 species of euglossines were sampled in PERD, and the most abundant was Eu/aema cingu/ata (Fabricius, 1804). At Viçosa, 10 species were samp led, E. nigrita was the predominant one. Methyl sali cylate attracted no males at both sites, in spite of large numbers of species and individuais sampled using this bait in other regions. The majority ofspecies and indi viduais were collected in the rainy season. Only 0,58% ofsampled males carried orchid pollinia (Cataselum Richard, Cycnoches Lindley and Coryanthes Hook) on their bodies. Emergence data of [our species 01' Eug/ossa Latreille, 1802 reared from trap nests suggest lhat sex ralio in Euglossini is not a constant w ithin the lribe. A li sl of 57 eugloss ine spec ies now known to occur in Mata Atlântica are oftered. KEY WORDS. Apidae, Euglossini, Atlantic Forest, conservation, bioindicator Há 35 anos machos de Euglossini vêm sendo coletados com auxílio de iscas contendo compostos aromáticos similares aos encontrados em flores de algumas Orchidaceae e de outras plantas e em alguns fungos. Foi LOPES (1963) o primeiro a verificar que machos dessas abelhas podiam ser atraídos e capturados utilizando-se armadi lhas contendo compostos aromáticos como iscas. Isto, associado a sua grande diversificação ecológica e taxonômica, abundância e importância em alguns ecossistemas, faz desses insetos candidatos a indicadores das qualidades ambientais de áreas naturais ou de conservação (BROWN 1991).

ABSTRACT. Effeets offorest fragmcntation on solitary wasps and bccs in an arca in Central Amazonia. The effects offorest fragmentation on tree-hole nesting so litary wasps and bees were investigated at li site 90 klll north ofManaus, Brazil. Wasp and bee faunas were monitored in continuous terra firme forest, forest fragments of I, 10 and 100 ha, natural gaps in continuous forest and deforested areas. These habitats were studied in tetms ofabundance, richness, diversity and similarity. The wasps and bees were monitored monthly during June 1988 through June 1990 by means of a trap-nests technique. A total of 1529 nests of wasps of 24 species and 405 nests of bees of 14 species were collected. The number ofspecies ofwasps and bees varied little among the habitats. The genus T/ypoxy/ol1 Latreille, 1796 (Sphecidae) accounted for 79% of wasp nests and Ce nlris Fabricius, 1804 (Allthophoridae) for 56% ofbee nests . Wasps showed an overall preference for cleared areas and li'agments of lha, whereas bees showed an overall preference for continuous forest and natural gaps. NeVet1heless, some spec ies ofwasps showed a prelerence tor nesting in continuo us forest and some bees a preference for deforested areas. Species found in deforested areas also nested in small size forest tragments . Thi s shows that species occ urring predominantly in c1eared areas can also colonize small forest ti·agments. The diversity ofwasps and bees was greater in continuous fores!. The composition of wasp and bee faunas 01' continuous forest was different from that ofaltered habitats . The similarity between the natural gaps and c1eared areas was the smallest. The data suggest that the forest adapted bees are more sensitive to habitat fragmentation than the corresponding species of wasps. 11 is concluded that the preexisting cavity nesting solitaty wasp and bee comlllunities were altered by the forest fragmenta tion. Howevcr. it appears that at least in part, the natural variati on in continuous forest cou ld be responsible for the results obtained Irom this study. KEY WORDS . Amazon ia, forest tragmentation, solitary bees, soli tary wasps, trapnests o desmatamento de florestas provoca, usualmente, a fragmentação da mata antes contínua, gerando o aparecimento de verdadeiras ilhas de matas isoladas umas das outras por áreas cobertas por pastagens ou por algum outro tipo de cultura. Além da perda de espécies provocada pela destruição da mata, podem ocorrer modificações nos fragmentos com o passar do tempo, em relação à diversidade e composição de sua fauna e t1ora, rompimento de antigas, e estabelecimento de novas interações entre as espécies, modificações nos processos biológicos e nas características do microc1ima e solo (LOVEJOY 1980).

We analyzed patterns of heterochromatic bands in the Neotropical stingless bee genus Melipona (Hymenoptera, Meliponini). Group I species (Melipona bicolor bicolor, Melipona quadrifasciata, Melipona asil6ae, Melipona marginata, Melipona subnitida) were characterized by low heterochromatic content. Group II species (Melipona capixaba, Melipona compressipes, Melipona crinita, Melipona seminigra fuscopilosa e Melipona scutellaris) had high heterochromatic content. All species had 2n =18 and n = 9. In species of Group I heterochromatin was pericentromeric and located on the short arm of acrocentric chromosomes, while in Group II species heterochromatin was distributed along most of the chromosome length. The most effective sequential staining was quinacrine mustard (QM)/distamycin (DA)/chromomycin A 3 (CMA 3 )/4-6-diamidino-2-phenylindole (DAPI). Heterochromatic and euchromatic bands varied extensively within Group I. In Group II species euchromatin was restricted to the chromosome tips and it was uniformly GC + . Patterns of restriction enzymes (EcoRI, DraI, HindIII) showed that heterochromatin was heterogeneous. In all species the first pair of homologues was of unequal size and showed heteromorphism of a GC + pericentromeric heterochromatin. In M. asil6ae (Group I) this pair bore NOR and in M. compressipes (Group II) it hybridized with a rDNA FISH probe. As for Group I species the second pair was AT + in M. subnitida and neutral for AT and GC in the remaining species of this group. Outgroup comparison indicates that high levels of heterochromatin represent a derived condition within Melipona. The pattern of karyotypic evolution sets Melipona in an isolated position within the Meliponini.

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