Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2003
Publication Date: 9/1/2003
Citation: Leskey, T.C., Bergh, J.C. 2003. A simple character for sex differentiation of pupae and pupal exuvia of the dogwood borer (lepidoptera: sesiidae). Florida Entomologist. 86:37-38
Interpretive Summary: As greater restrictions are placed on use of conventional insecticides to control pests of tree fruit, the importance of effective monitoring systems to detect insect pests in orchard ecosystems grows. In order to develop effective monitoring systems, one must have a thorough understanding of the biology of the pest species. The dogwood borer is an important indirect wood-boring pest of apple grown on size-controlling rootstocks because of the tendency of these rootstocks to produce burr knots. Adult females lay eggs on or near burr knot tissue found above and below the graft union. Larvae feed on this tissue and eventually pupate. When they emerge as adult moths, they leave behind pupal cases. One can differentiate the sex of either the live pupae or the pupal cases of this species by counting the number of rows of spines present on fused terminal abdominal segment. Four rows are present on females and three rows are present on males.
Technical Abstract: The sex of dogwood borer, Synanthedon scitula Harris (Lepidoptera: Sesiidae), pupae and pupal exuviae can be easily differentiated based on characteristics of the fused terminal abdominal segment. In males, it is composed of segments 8-10 and has three distinct rows of posteriorly projecting spines, whereas in females, it is composed of segments 7-10 and has four distinct rows of posteriorly projecting spines.