Published online by Cambridge University Press: 31 May 2012
Unequal responses to acephate and carbaryl were found among four populations of Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough). Within a single population, response of almost half of sibling groups tested with either toxicant differed significantly from one another. Using electrophoresis, we related variation in sibling group responses to quantitative differences in esterase isozymes. Potential use of genetic assays in pre-spray population surveys is discussed.