Genetic improvement of Helicoverpa zea nuclear polyhedrosis virus as a biopesticide

Helicoverpa tea nuclear polyhedrosis virus, which was previously registered and commercially produced as a pesticide (Elcar), was genetically improved to control the cotton bollworm, H. tea. A significant reduction in the time required for this virus to kill EI. tea larvae was achieved by inserting a mite gene encoding a potent insect-selective neurotoxin gene, tox34, into the viral gene encoding ecdysteroid UDP-glucosyltransferase. Under the control of an early viral promoter, expression of tox34 during infection resulted in 50% mortality or paralysis within 40 h after virus treatment. The ability to genetically improve the properties of this virus as a pesticide provides the opportunity to develop a commercially viable product to control this pest species. (C) 1997 Academic Press.