Comparative Susceptibility of Heliothis virescens and H. zea to the Nuclear Polyhedrosis Virus Isolated from Autographa californica123

Abstract
Heliothis virescens (F.) was more susceptible to a nuclear polyhedrosis Virus (NPV) isolated from Autographa californica (Speyer) than to a commercial formulation of an NPV isolated from Heliothis species. H. zea (Boddie) was less susceptible to the A. californica NPV than H. virescens (ca. 10-fold difference), and therefore, the LD50 and LT50 for H. zea were higher. Viral mortality in the pupal stage was higher among treated insects but did not follow a dose response.