Morphological and Molecular Taxonomy of Field-bean Pod Borer, Adisura atkinsoni Moore With A Note on Comparative Larval Chaetotaxy with Helicoverpa armigera Hübner

Field-bean pod borer, Adisura atkinsoni Moore (Lepidoptera: Noctuidae) is a widely distributed pest in Asia and Africa. Like gram pod borer, Helicoverpa armigera Hubner also attacks pods, hence enumeration of distinguishing characters between these two pests is important for proper taxonomic identification. For the first time, herewith we provide the larval taxonomy based on chaetotaxy and DNA barcode data using the mtCOI gene. In larvae, dorsal setae (D1 and D2) were present in both thoracic and abdominal segments, however, Subdorsal (SD) and Subventral Setae (SV) varied in these segments. In A. atkinsoni, Ventral seta (V1) is present in all three thoracic segments, which were absent in larvae of H. armigera. While the arrangement of crochets is biordinal, biserial in A. atkinsoni and uniordinal uniserial in H. armigera. In adult males, the aedeagus knife shaped, blunt and narrow at one end; the vesica is membranous and lined with an elongated spine like cornutii. The phylogenetic analysis with the species from the genera Adisura, Heliothis, Pyrrhia and Helicoverpa revealed that all the species of Adisura formed a separate group. The phylogenetic tree also ascertained that the genus A. atkinsoni was found to be closest to H. armigera implying the importance of the morphological distinction between these two. As the larvae are damaging stage by feeding on pods, they could be invasive and hence the identification characteristics given here will help intercept and identify them in quarantine stations.