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United States Department of Agriculture

Agricultural Research Service

Title: Mortality and Feeding of Mid-Instar Larvae of Helicoverpa Zea and Heliothisvirescens Fed a Wild Strain Or a Recombinant Strain of Baculovirus Heliothis Expressing An Insect-Specific Toxin

item Ignoffo, Carlo
item Wong J F H, - E I DUPONT
item Saathoff, Stephen

Submitted to: Journal of Invertebrate Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 10, 1999
Publication Date: N/A

Interpretive Summary: Baculoviruses that attack insect pests, have been explored for possible commercial development into safe, effective, biorational pesticides. Baculoviruses, however, may be more effective biocontrol agents if they can be modified to kill quicker and/or reduce feeding damage. In collaboration with industry we tested a modified virus that was genetically engineered to oproduce a paralyzing insect-specific toxin. The modified virus significantly decreased the killing time and significantly reduced the amount of larval feeding over that of the unmodified, native virus. Enhancing the insecticidal activity of baculoviruses can stimulate industrial acceptance and commercial development of safe, rational, biocontrol agents.

Technical Abstract: A recombinant of the Heliothis/Helicoverpa single-enveloped nucleopolyhedrosis virus (RcHzSNPV), carrying a gene encoding an insect specific toxin from the scorpion, Leiurus guinquestricatus significantly increased the rapidity of kill and reduced feeding by larvae of Heliothis virescens and Helicoverpa zea over that of its parental, wild-type strain (WtHzSNPV). The RcHzSNPV at 1.0 OB/mm**2 killed or paralyzed H. virescens or H. zea larvae ca. 47% or 82% faster, respectively, than did the WtHzSNPV. Larvae not exposed to virus produced 3- to 5-fold more feces than larvae exposed to the RcHzSNPV, and 2- to 3-fold more feces than larvae exposed to the WtHzSNPV. Increasing the rapidity of kill and reducing larval feeding are attributes that enhance the use of recombinant baculoviruses as potential biorational pesticides.

Last Modified: 5/5/2015
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