Morphological variation of the parasitic wasp Paracentrobia subflava (Hymenoptera: Trichogrammatidae) emerged from different leafhopper species

Abstract

The parasitic wasp Paracentrobia subflava (Girault) (Hymenoptera: Trichogrammatidae) develops within the eggs of the corn leafhopper Dalbulus maidis (DeLong) (Hemiptera: Cicadellidae), one of the most important pests in maize throughout the Americas. The aim of the present study was to determine whether variation occurs in female and male body size and male genitalia of P. subflava emerged from eggs of D. maidis and two other host species: Dalbulus elimatus (Ball), and Dalbulus quinquenotatus (DeLong and Nault), representing different species groups within the genus. Body variation of the emerged adult parasitoids was evaluated using traditional morphometrics and male genitalia shape variation was assessed using geometric morphometrics. Female parasitoids emerged from D. elimatus eggs had significantly larger hind tibiae, wings and ovipositor. Most antennal variables also exhibited significant differences in females emerged from D. elimatus. In contrast, little differentiation was found among parasitoid males emerged from the different Dalbulus hosts. Accordingly, shape of male genitalia was similar when P. subflava developed in each of the three Dalbulus host eggs. Egg size differs among the examined Dalbulus species, but does not seem to be associated with patterns of variation in parasitoid size. Implications of this morphological variation for parasitoid identification and its relationship with host egg size and structure are discussed.