Re-Examination of Morphological Variations in the Female Internal Genitalia of Helicoverpa armigera and Helicoverpa zea (Lepidoptera: Noctuidae) for Identification and Pest Management

Abstract

Two of the most serious agricultural pests, Helicoverpa armigera (Hübner) and Helicoverpa zea (Boddie) (both Lepidoptera: Noctuidae), are similar in their appearances. To distinguish them, morphological characters of female internal genitalia were re-examined. Specimens were collected from 7 regions in 17 countries. All specimens were identified in advance by molecular methods. Significant differences were observed in the length of the bursa copulatrix, ductus bursa, and pigmented area on the base of appendix bursa. Helicoverpa armigera had dense spicules on the luminal surface of the appendix bursa which were absent on the corresponding surface in H. zea. Additionally, differences of length on these parts in female genitalia will be helpful for identification. We are confident these morphological characters will advance resolution of noctuid speciation by taxonomists to properly identify these species based on distinguishing features of the female genitalia.