CASTE SIZE DIFFERENCES IN POLISTES-GALLICUS (L) (HYMENOPTERA-VESPIDAE)

In several species of wasps belonging to the genus Polistes, the first workers to emerge during the colonial cycle are smaller than the foun dresses. As the cycle proceeds, the emerging workers are larger and la rger, so that when the future reproductives appear they are no larger than workers of the same age. This study analyzes the size differences found in the workers and foundresses in a sample of 638 females colle cted in the course of one year. After anatomical analysis, each female was assigned to one of the following groups: foundress, future foundr ess and worker. Each individual was measured for maximum head width an d right wing length. Although the size of emerging females also increa ses in P. gallicus as the season advances, workers are always smaller than the foundresses, and the future reproductives always larger than workers found on the nest at the same time. Results also suggest that the smaller future foundresses are selected out during overwintering.