Mischocyttarus latior (Fox) occurs in Bolivia and in Brazil and has been recorded in Cerrado areas from southeast Brazil. The objectives of the present study were to describe the immature stages of M. latior, determine the development time of the immature stages and determine which factors affect its duration. Daily mappings were performed from March 1994 to August 1995 in 22 nests. Two nests were also collected and dissected to characterize immatures. Larvae presented five instars and unlike most Mischocyttarus, M. latior has only a single lobe on the abdominal sternite, which is vestigial in third instar, emergent in fourth instar and fully developed in the fifth instar larvae. The mean duration of the immature stages (from egg laying to adult emergence), was 67.38 ± 9.41 days, a longer period than the total duration of the immature stages of other previously studied species. The development time of the immatures was variable, depending on the colony development stage, with development times being quicker in pre-emergence colonies.

New records of social wasps in the State of Piauí are presented, contributing to an increased knowledge of this group in this poorly studied region. This study documents new occurrence records for 12 social wasp species and extends their distribution. Atualização do Conhecimento Sobre Vespas Sociais (Hymenoptera: Vespidae) no Estado do Piauí, BrasilResumo. São apresentados novos registros da fauna de vespas sociais em localidades do Piauí, contribuindo para o aumento do conhecimento desse grupo de organismos na região. Este estudo registra a ocorrência de 12 novos registros de vespas sociais, ampliando suas distribuições.

This paper aimed to study the division of labor between queen and workers, division of labor by age range and sequence of behavioral patterns exercised by females and males from Mischocyttarus latior (F.) colonies. Behaviors of 13 dominant females (queens), 68 subordinate (workers) from emergence until they are 77 days and 12 males in 37 colonies were quantified during 545 hours. There were 23 behavioral acts registered divided into five categories. Both dominant females as the workers showed a behavioral repertoire of 23 items, while males only 15. Dominants remain longer on the nest than subordinates and exercise exclusively the behavior of oviposition and rubbing gaster on the nest and share 21 behaviors with the workers. Males foraged nectar, preys and water, and exercise other behaviors, mostly related to social activity. All behaviors can be performed by any potentially worker at any age.