Post introductory risk assessment studies on<i>Zygogramma bicolorata</i>(Coleoptera: Chrysomelidae), a classical biological control agent of<i>Parthenium hysterophorus</i>(Asteraceae) in India

Abstract

Abstract Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae), a biological control agent of Parthenium hysterophorus L. (Asteraceae), was feeding on leaves of Helianthus annuus in India, raising concerns of its host range. Based on the age grading technique, it was shown that the majority of Z. bicolorata on sunflower plants at any time were reproductively immature. This establishes that Z. bicolorata does not pose any risk to sunflower in India.