The Effect of Eastern Tent Caterpillar (Malacasoma americanum) Infestation on Fall Webworm (Hyphantria cunea) Selection of Black Cherry (Prunus serotina) as a Host Tree

Abstract

This study determined whether the presence of Eastern tent caterpillars on black cherry affects selection of the same tree by fall webworms in the same season. Five study sites were selected, each containing 30 to 50 black cherry trees, which were marked and measured. The total number of Eastern tent caterpillar nests was counted on each tree in June 2001. Fall webworm nests were recorded as they developed throughout the summer. A logistic regression showed a significant difference (P < 0.01) in the use of previously colonized vs. uncolonized trees by the fall webworm. Fall webworms were less likely to occur on trees that had been used by Eastern tent caterpillars earlier in the season. At the end of the study period, 8.5% of the trees had been used by both species and fall webworms alone had colonized 21% of the trees observed.