Linear Alkanes and Reproductive Status of Polistes versicolor (Hymenoptera: Vespidae) Females in Winter Aggregates

Female wasps such as Polistes versicolor can form aggregates to face weather conditions that are not suitable to sustain their colonies. The interactions between individuals in these aggregates, just as in other associations, are probably facilitated by chemical signals. Of these compounds some of the most efficient during social interactions of insects are those called contact pheromones or superficial pheromones. This special type of pheromones, known as cuticular hydrocarbons, can be found in insects cuticle. They facilitate the differentiation of caste, species and nestmates, and may be important indicators of dominance as well as fertility. Some studies indicate that linear alkanes are important cuticular compounds for intraspecific recognition and discrimination. The aim of this study was to evaluate the relationship between reproductive physiologic condition and the linear alkanes present in the cuticle of females of P. versicolor in aggregates employing Gas Chromatography with Flame Ionization Detector (GC-FID). Females from distinct aggregates were differentiated by the chemical composition of their cuticle. In each aggregate, there was difference in cuticular chemical composition between females with different ovarian development degrees, allowing the distinction between inseminated and non-inseminated females.