CONTROL OF FOREST TENT CATERPILLAR, MALACOSOMA-DISSTRIA (LEPIDOPTERA, LASIOCAMPIDAE), WITH DIMILIN

Dimilin (25% wettable powder) was mixed in water and sprayed from a Grumman Agcat aircraft equipped with four micronair units at the rate of 70 g (active ingredients) / 4.67 Llha (I oz/0.5 U.S. gal per acre) on two stands of trembling aspen, Populus tremuloides Michx., heavily infested with forest tent caterpillar, Malacosoma disstria Hübner. The material was applied when the insects were in the first and second instars and the trees were starting to flush. Spray deposit analysis using a dye, Rhodamine-B, in the spray mix and spray plates in the plots indicated that conditions for spraying in the morning were better than those in the evening as expected. Total control of the forest tent caterpillar with very little defoliation of the trees was achieved. © 1979, Entomological Society of Canada. All rights reserved.