Gonad-Specific Virus of Helicoverpa zea Does Not Affect Infectivity of Nuclear Polyhedrosis Virus

Abstract

A gonad-specific virus (GSV), an enveloped, rod-shaped virus, which prevents the development of normal ovaries and testes of Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) has been suggested for use in biological control of H. zea (Raina an Adams 1995). Because the GSV resembles the Hz-1 virus which was described as a persistent infection in an H. zea tissue culture that inhibited infection by other viruses, this research was designed to determine if the GSV would interfere with infection of H. zea larvae by its homologous nuclear polyhedrosis virus (HzSNPV) which is currently being used in biocontrol of H. zea and H. virescens. In three of four tests, there was no significant difference in LC50 (i.e., the 95% confidence intervals overlapped) for HzSNPV in larvae from normal moths and larvae from moths injected with GSV. Surviving larvae from the GSV-injected moths produced 97.8 to 100% agonadal moths. This indicates that GSV does not protect agonadal larvae from infection by NPV. Thus, release of GSV into the natural population of H. zea should not interfere with use of the more virulent NPV for control H. zea.