Arquitetura de ninhos de Mischocyttarus cerberus styx Richards, 1940 (HYMENOPTERA, VESPIDAE)

The nest architecture of Mischocyttarus cerberus styx was described. This population nidificated in the arboreto of “Navarro de Andrade” Forest Station, in Rio Claro, São Paulo State. The wasps build an only little paper comb (mean of 30 cells and 3,5 cm2), with an excentric thin peduncle attached on the tree trunk or branch. The cells are used up to five times and this high nest reutilization is useful for the maintenance of little monoginic colonies. The nest site, the size and color of the comb were considered as defensive adaptations used by the wasps against natural enemies. The nest growing is highly correlated to the number of adult wasps