Dogwood Borer (Lepidoptera: Sesiidae) Flight Activity and an Attempt to Control Damage in ‘Gala’ Apples Using Mating Disruption

Abstract

‘Gala’ apple trees had a high incidence of burr knots (adventitious root primordia) produced on the trunk. Dogwood borer, Synanthedon scitula (Harris), infested many of these growths. Mating disruption using a sex attractant for dogwood borer, (Z,Z)-3,13-ODDA, did not control dogwood borer injury. In addition to other variables inherent to mating disruption (dispenser release and application rate, pest density, environmental factors), one potential reason for the failure was an inadequate conception of the dogwood borer sex pheromone composition. Therefore, the composition of dogwood borer pheromone should be reexamined. Traps baited with lilac borer, Podosesia syringae (Harris), lures were more sensitive for capturing dogwood borer males than traps baited with lures for dogwood borer. This is difficult to explain because the lures purportedly are identical. This difference in trap response further supports the need for reexamination of the pheromone blend compositions for each species. A complex of seven sesiids was attracted to both dogwood borer and lilac borer traps; captures of all were almost entirely eliminated by permeation with (Z,Z)-3,13-ODDA. There was a bimodal pattern of adult activity, with an early peak trap capture in May–June, and a later peak in July–August. The hypothesis of apple producing a later period of dogwood borer emergence than from dogwood was supported. This will complicate control in ‘Gala’ using current borer insecticides (e.g., chlorpyrifos, endosulfan) because of the proximity of harvest in this early-maturing variety with the ovipositional period of dogwood borer.