Flight Phenology of the Dogwood Borer (Lepidoptera: Sesiidae) and Implications for Control in Cornus florida L.1

Abstract

Emergence and seasonal flight activity of Synanthedon scitula (Harris) was determined by means of pheromone traps baited with Z, Z-octadecadien-l-ol acetate and screen emergence cages, and by sampling infested trees. A base temperature of 4°C gave the lowest coefficient of variation in degree-day (DD) summations between years and was used for relating cumulative male capture to physiological time. Date of first capture ranged from 12 to 26 May, corresponding to a mean DD accumulation of 1,271 in central Kentucky. Flight activity continued until early October and was bimodal, with peaks in late May to June and August to September. Evidence is presented that the earlier flight pulse includes most emergence from dogwood, and that the larger, late-summer flight pulse consists mainly of adults from apple and possibly other hosts. Consequently, in spite of its lengthy flight period, S. scitula in dogwoods can be controlled with a single application of chlorpyrifos or lindane in early June.