Introduction

The Brazilian Atlantic Forest is of great relevance to biological conservation, and is among the areas in South America with the highest levels of diversity and endemism. The aim of this study was to survey the social wasp species in the subfamily Polistinae in Ubatuba, São Paulo state, in southwestern Brazil. Collecting work was conducted from May 2007 to May 2008 using attractive PET bottle traps and active searching. Twenty-one species belonging to eight genera were found, among which some may be considered rare in southeastern Brazil such as Mischocyttarus parallelogrammus and Polybia catillifex. The most abundant species were Agelaia angulata (64.31%), Agelaia nr. centralis (10.08%) and Angiopolybia pallens (8.49%). A correlation between species richness and relative humidity (r = 0.6435; p = 0.0176) was observed. Values of species richness were a little higher in the super humid (Sm = 11) than in the less humid (Sm = 9) season. This suggests that this season may have more favorable environmental conditions for a greater richness of species to found colonies. Despite not having a very high species richness compared with other surveys, the collected species in this study can be considered rare in southeastern Brazil, emphasizing the complexity of the Atlantic Forest biome and its relation to the diversity of wasps.

The aim of this study was to analyze the distribution pattern of the food collected among groups of individuals in Mischocyttarus drewseni colonies. This behavior is one of the first actions exhibited by the foragers when they arrive in the colonies. Regarding nectar and prey collection, 95.90% of the collected nectar was given to larvae, whereas 3.57% to dominant individuals and 95.94% of the collected prey were given to the larvae, 2.54% to the dominant members, while the remainder of both was given to the workers. Despite not being significant, it was possible to observe a difference in food distribution among larvae, with larger larvae receiving more food than others. When the forager returns to the nest with pulp, it adds this material to cells in 64.29% of the times. Males showed agitated behavior with the arrival of the foragers, and sometimes took the foraged material from them.