Notes on Brood Morphology and the Development of the Neotropical Eusocial Wasp Mischocyttarus cerberus (Hymenoptera, Vespidae, Polistinae)

Mischocyttarus cerberus stands out among the most investigated species of the eusocial paper wasp, in Brazil. While the adult characteristics were relatively well reported in the earlier studies, very meager information was available regarding their immature stages. This study provides a description of the immature morphology of the general brood of M. cerberus, by studying the number of instars and analyzing the degree of influence exerted by some of the environmental factors on the individuals in the immature phases. This work involves a detailed study of 72 wasp colonies from Rio Claro and Ribeirão Preto. Using the larvae drawn from 41 nests, the number of instars was calculated; besides, the degree to which a few environmental factors could affect the immature brood development was assessed in 31 nests. Eggs showed patterns similar in terms of form and size to that of the species described earlier. The two ventral lobes, characteristic of the Mischocyttarus larvae, were fully developed only in the fifth instar. The measurements of the larval heads in the five instars found concurred with the earlier reports for most of the social wasps. Furthermore, the larval stages took longer to develop, which could be related to the greater susceptibility of the larvae to the prevailing environmental factors. From the results of our study, we concluded that the M. cerberus showed the typical developmental pattern in the immature stages of its genus.