Date of this Version
Journal of Economic Entomology 65:5 (1972), pp. 1484–1485.
Pin oaks, Quercus palustris Muenchhausen, are one of the important shade trees in west Tennessee. The horned oak-gall wasp, Plagiotrochus cornigerus Osten Sacken, causes a deformation of the twigs and leaves of the tree. In 1965, K. E. Stewart, an entomologist at the University of Toronto, Ontario, Canada, injected pin oaks with systemic insecticides to evaluate their effectiveness in controlling the leaf gall and the stem gall caused by the horned oak-gall wasp. He found oxydemeton-methyl ec at a rate of 25 g AI/in. diameter and technical demeton at a rate of 3 g AI/in. diameter were the best materials tested, each resulting in 83% control. In the present study we attempted to evaluate effectiveness of several systemic insecticides by applying them at the base of the tree.