MORPHOLOGY OF IMMATURE STAGES AND ADULTS OF HELICOVERPA ARMIGERA

Abstract

Helicoverpa armigera (Hübner) is a highly polyphagous insect pest of worldwide occurrence, including India. In the present study, a detailed morphological assessment of H. armigera showed the following: Typically dome-shaped egg with ribbed surface; larva having coriaceous skin, biordinal crochets and 11 primary setae on the prothoracic segment; pupa adecticous and obtect with prominent posterior tip cremaster; and adult forewings characterized by the presence of 7-8 black spots along the apical margin and a reniform shaped brown marking, more prominent on the underside. Adults exhibit sexual dimorphism in the colour of vestiture and forewings. The genitalic traits like the presence of usually 12 or less sets of cornuti in aedeagus, apically broadened harpe having length ranging between 4.5 to 4.9 mm and a single lobe at the base of everted vesica in males, and four distinct signa on bursa copulatrix in females, also distinguishes it from other congeneric species.