Species of Eurydice (Isopoda, Flabellifera) from southern Brazil

This paper reports species of Eurydice (Isopoda, Flabellifera) occurring on the continental shelf of southern Brazil, from lat. 22º00'S. Three species are recorded. E. littoralis (Moore, 1902), is a new occurrence from Brazil. Detailed illustrations and new morphologi cal data are furnished for this species hitherto inadequately described. E. elongata sp. n. and E. emarginata sp. n., are new to science. The flagellar process on the antenna 2, reported in three species of Eurydice, seems to be an exclusively male characteristic, and probably it will also occur in the males of most of the already described species. Genus and species diagnosis are provided, together with a classification key for all species recorded up to date from southern Brazil. All available distributional and ecological infor mation completes the account of each species.No presente trabalho faz-se um levantamento das especies do gênero Eurydice (Isopoda, Flabellifera) ocorrendo na plataforma continental centrosul do Brasil, a partir da Lat. 22º00'S. Tres espécies são assinaladas para a região: E. littoralis (Moore, 1902), E. elongata sp. n. e E. emarginata sp.n. Novos dados morfológicos e detalhadas ilustrações são apresentadas para a espécie E. littoralis. O processo flagelar da antena 2, observado em três espécies de Eurydice, parece constituir uma característica exclusiva dos machos, donde se pressupõe possa também ser encontrado em outros machos de espécies já descritas. São fornecidas diagnoses para o gênero e espécie, assim como urna chave de classificação para todas as espécies tratadas. Tanto quanto possível, observações ecológicas completam a descrição das espécies

Parasitic mites as part-time bodyguards of a host wasp

Some bees and wasps that host mites have peculiar pocket-like structures called acarinaria. These have long been considered as morphological adaptations to securely transfer beneficial mites into nests, and thus are thought to be the product of a mutualistic relationship. However, there has been little compelling evidence to support this hypothesis. We demonstrated that the parasitic mite Ensliniella parasitica, which uses acarinaria, increases the reproductive success of its host wasp Allodynerus delphinalis by protecting it from parasitoid wasps. Every time the parasitoid Melittobia acasta accessed a prepupal or pupal wasp host cell, adult mites attacked it, continuously clinging to it and possibly piercing the intersegmental membrane of the parasitoid with their chelicerae. Subsequent mortality of the parasitoid depended on the number of attacking mites: an average of six mites led to a 70% chance of mortality, and 10 mites led to a 100% chance of mortality. In this way, parent mites protect the food source (juvenile wasps) for themselves and ultimately for their offspring. We propose that wasps evolved acarinaria to maintain this protective guarding behaviour