Extracts of the green-colored perivisceral fat body of newly ecdysed Manduca sexta pupae stimulate mitosis in midgut stem cells of Heliothis virescens cultured in vitro. Using a combination of cation- and anion-exchange chromatography, we have isolated a protein from these fat body extracts that accounts for the observed stem cell proliferation. SDS-PAGE analysis of the protein results in a sin...

Genetic models have been used to examine the evolution of insecticide resistance in pest species subject to data and assumptions regarding genetic, biological, and operational parameters. We used time-series data on pyrethroid tolerance and simple genetic models to estimate underlying genetic and biological parameters associated with resistance evolution in tobacco budworm,Heliothis virescens (...

Binding of the Bacillus thuringiensis Cry1Ac toxin to specific receptors in the midgut brush border membrane is required for toxicity. Alteration of these receptors is the most reported mechanism of resistance. We used a proteomic approach to identify Cry1Ac binding proteins from intestinal brush border membrane (BBM) prepared from Heliothis virescens larvae. Cry1Ac binding BBM proteins were de...