Role of juvenile hormone in oogenesis, chemical profile, and behavior of the wasp Mischocyttarus consimilis (Vespidae: Polistinae)

Abstract

In social insects, juvenile hormone (JH) affects the degree of ovarian development, reproductive status, and temporal polyethism in workers. JH also contributes to determining the epicuticular chemical composition, which differentiates the castes of queens and workers. However, a few studies have evaluated the action of JH on behavioral ontogeny, cuticular chemical profile, and oocyte length and width, especially in social wasps of independent foundation. Therefore, the following hypotheses were tested: (i) topical application of JH changes the behavioral ontogeny of newly emerged workers; and (ii) changes might be detected in the cuticular chemical composition and oocyte length and width of newly emerged females receiving topical application of JH. The treatment consisted of application of JH, at a concentration of 25 µg.µL⁻¹ in acetone, to 1-day-old Mischocyttarus consimilis workers. The application of JH to newly emerged M. consimilis females significantly altered oocyte length and width, with effects on behavioral ontogeny and the cuticular chemical compounds signaling these parameters in the colony. No effects of the solvent on female physiology were observed, reinforcing that the observed changes were due to the specific effects of JH.