ENOCLERUS SPHEGEUS (COLEOPTERA: CLERIDAE), A PREDATOR OF DENDROCTONUS PONDEROSAE (COLEOPTERA: SCOLYTIDAE) IN THE BLACK HILLS

Abstract

AbstractEnoclerus sphegeus Fabricius adults were most abundant on trees infested with Dendroctonus ponderosae Hopkins in May and June of 1966 and 1967. Greatest numbers of adults were observed on the bole from 0 to 5 ft aboveground, apparently in response to the activity of other scolytids. In the laboratory, each adult killed about 1 D. ponderosae per day, and each larva killed about 25 D. ponderosae during development. Mean larval densities were generally less than 0.2 per square foot at four different sampling heights on the tree bole during the overwintering period. Densities were greatest at all heights in July. Maximum larval density was observed at the 1.5-ft height. Larvae began leaving the trees for pupation sites in July of both years. It is estimated that adult clerids consume less than 1% of the adult beetle population during their attack period and the clerid larvae kill 5–11% of the beetle brood.