Feeding Tests of Insecticides, 1975

Feeding tests of the toxicity of 15 insecticides were conducted on last stage western spruce budworm. Insects were selected from the 58th to 60th generations of a non-diapausing laboratory colony. Five concentrations serially diluted from a freshly formulated concentrate were used in each of 3 replications for each insecticide. All insecticides were formulated in reagent grade acetone on the basis of weight/volume concentrations of the active ingredient. Two hundred μl of each concentration were added to 10 cc of molten artificial diet and the diet was stirred thoroughly. When hardened, each diet mold was fed to 10 larvae. Mortality was tallied after 7 days. Mexacarbate was used as the standard for comparison.