Antennal lobe structure and glomerular organization in parasitoid Microplitis croceipes: A confocal microscopy study

Microplitis croceipes (Hymenoptera: Braconidae) is a larval parasitoid of Heliothis/Helicoverpa spp. Previous studies by our group have showed key differences in the responses of both sexes of this parasitoid to host-related odors. Females showed greater responses to green leaf volatiles (GLVs) released immediately after herbivore attack, whereas males exhibited greater responses to herbivore-induced plant volatiles (HIPVs) emitted hours after damage. To investigate the neural basis underlying these differences in the response of both sexes to host-related odors, this study was conducted to characterize and compare the glomerular antennal lobe structures in male and female M. croceipes, by using a combination of axonal tract tracing techniques, confocal microscopy, and three-dimensional (3D) computer analysis. Here, we present a detailed description of the morphology of glomerular organization of the antennal lobe of both sexes, including digital 3D models of the glomeruli.