O gênero Rhathymus é composto apenas por cleptoparasitas obrigatórios cujos hospedeiros conhecidos pertencem todos ao gênero Epicharis (Apidae, Centridini). Para apenas quatro das 20 espécies válidas havia previamente registro de hospedeiros. O presente trabalho documenta, pela primeira vez, o parasitismo de Rhathymus friesei sobre o hospedeiro Epicharis (Epicharoides) picta.

The genus Rhathymus contains only obligatory cleptoparasitic species whose hosts belong to the genus Epicharis (Apidae, Centridini). Host information is available for only four of the 20 species of Rhathymus. In this note a new host record is added, in which the parasitism by R. friesei on nests of Epicharis (Epicharoides) picta is documented.

Para sua defesa, abelhas-sem-ferrão (Meliponini) coletam resinas vegetais para colar nos invasores de seus ninhos como formigas ou abelhas cleptobióticas causando a imobilização deles. O objetivo desse artigo é identificar todas as partes das operárias das abelhas-sem-ferrão que tocam na resina. De interesse especial são aquelas partes do corpo que repelem as resinas. Para isso, extensas observações foram realizadas tanto durante a coleta, como no tratamento e na aplicação das resinas. Durante a manipulação da resina, todos os tarsos das operárias encostam-se à resina quando andam sobre sua superfície. Para transportar a resinas das plantas para os ninhos durante o vôo de coleta, a resina é transferida para a corbícula via tarsos e basitarsos das pernas anteriores e médias. Uma vez coladas na resina ou depois que a corbícula foi descarregada, as pernas das operárias são meticulosamente limpas. Utilizadas na manipulação, corte e aplicação da resina pegajosa, somente as pontas das mandíbulas parecem ter, pelo menos temporariamente, propriedades repelindo resina.

For their nest defense, stingless bees (Meliponini) collect plant resins which they stick on intruders like ants or cleptobiotic robber bees causing their immobilization. The aim of this article is to identify all parts of stingless bee workers contacting these sticky resins. Of special interest are those body parts with anti-adhesive properties to resin, where it can be removed without residues. For that, extensive behavioral observations during foraging flight, handling and application of the resin have been carried out. When handling the resin, all tarsi touch the resin while walking above it. For transportation from plants to the nest during foraging flight, the resin is packed to the corbicula via tarsi and basitarsi of front and middle legs. Once stuck to the resin or after the corbicula had been unloaded, the bee's legs have to be cleaned thoroughly. Only the tips of the mandibles, that form, cut and apply the sticky resin, seem to have at least temporarily resin-rejecting properties.

Melipona quadrifasciata Lepeletier, 1836, regionally known as "mandaçaia", has been traditionally divided in two distinct subspecies: M. quadrifasciata anthidioides and M. quadrifasciata quadrifasciata. The main difference between the subspecies refers to the yellow metasomal stripes which are continuous in M. q. quadrifasciata and discontinuous in M. q. anthidioides. This study investigated the geographic differentiation in the metasomal stripes and characterized the restriction sites in the mtDNA of both chromatic types. Specimens from 198 localities were examined, and the variation observed in the pattern of stripes was grouped into distinct classes. The distribution pattern found in the present work agrees with the previously reported pattern: M. q. quadrifasciata inhabits the southern portion of the distribution, from Misiones, Argentina, southeastern Paraguay and Rio Grande do Sul to southern São Paulo, and M. q. anthidioides ranges from northeastern São Paulo to the northern Diamantina Plateau, Bahia, and westwards to the central portion of the Goiás state. It is documented for the first time the occurrence of two populations with continuous stripes inhabiting disjunct areas in relation to M. q. quadrifasciata - one in northern Minas Gerais and another in northeastern Bahia and Sergipe. The data of RFLP showed two restriction patterns, one present in M. q. quadrifasciata, and another in M. q. anthidioides and in populations with continuous metasomal stripes from northern Minas Gerais and northeastern Bahia and Sergipe. The observed patterns of geographic differentiation of M. quadrifasciata suggests the occurrence of repeated events of geographical isolation, followed by range expansion, that occurred probably during the cycles of climatic changes in the Pleistocene.