Larval body colour polymorphism in Helicoverpa armigera (hubner) populations across India

Abstract

Helicoverpa armigera (Hubner) is a widely distributed insect pest of high agricultural importance. This study comprehensively presents the morphological characterization of H. armigera populations from India, based on larval body colour patterns. Significant differences were observed among the populations in respect to frequency of occurrence of eleven distinct larval colour morphs. The characteristic pigmentation pattern on the lateral band of larvae was also found to be a variable trait, with the majority of individuals irrespective of geographical location, exhibiting no pigmentation on their lateral bands. A wide variation was also observed in the intensity of black pigmentation on the larval body, with the maximum recorded from the Coimbatore population. The dendrogram based on selected traits showed clear cut differentiation of studied populations into two major groups. Such variations can possibly be due to the existence of different subspecies among the Indian H. armigera populations.