Evaluation of Neem-Derived Insecticides for Control of Western Tent Caterpillar, 1993

Colonies of late instar caterpillars feeding on mountain mahogany that had created tents were used for this experiment. All caterpillars on an individual tent were sprayed with each treatment and the larvae were subsequently collected after sprays had dried. Plots consisted of single colony of larvae and there were four replications of each treatment arranged in a randomized complete block design. Collected larvae were returned to the lab and separated into groups of approximately ten larvae per petri dish. These were initially fed treated foliage from the same plant from which they were collected; after the third day other foliage from untreated plants was substituted. Condition of larvae was assessed three and seven DAT. Since individual colony size varied (201 maximum; 27 minimum; 90 mean), percent mortality of each colony was used for analysis.