Mortality and feeding of mid-stadium larvae of Helicoverpa zea and Heliothis virescens fed a wild strain or a recombinant strain of Baculovirus heliothis expressing all insect-specific toxin of the scorpion Leiurus quinquestriatus hebraeus

A recombinant of the Heliothis/Helicoverpa single-enveloped nucleopolyhedro sis virus (RcHzSNPV), carrying a gene encoding an insect-specific toxin fro m the scorpion, Leiurus quinquestriatus herbraeus, significantly increased the rapidity of kill and reduced feeding by larvae of Heliothis virescens a nd Helicoverpa tea over that of its parental, wild-type strain (WtHzSNPV). The RcHzSNPV at 1.0 occlusion bodies/mm(2) killed or paralyzed H. virescens and H. tea larvae ca. 1.5-fold and 1.7-fold quicker, respectively, than th e WtHzSNPV strain. Larvae not exposed to virus produced 3- to 5-fold more f rass than larvae exposed to RcHzSNPV, and ca. 2- to 3-fold more frass than larvae exposed to WtHzSNPV. Increasing the rapidity of kill and reducing la rval feeding are attributes that enhance the use of recombinant baculovirus es as potential biorational pesticides.