Survival and growth of Bt-resistant and nonresistant soybean loopers on leaves collected from the upper, middle and lower canopy of Bt- and nonBt-cotton plants were studied. Survival of Bt-resistant and nonresistant larvae after 10 days was not affected by the cotton variety. However, nonresistant larvae fed leaves from nonBt-cotton had significantly higher survival through pupation and adult emergence than those fed Bt-cotton. Survival of larvae from both cultures through pupation and adult emergence was significantly higher when fed leaves from nodes in the middle than from upper or lower canopy of both varieties of cotton. Nonresistant larvae fed leaves from nonBt-cotton had a significantly greater larval weight and shorter development period than those fed Bt-cotton.