Physical Barriers to Prevent Dogwood Borer (Lepidoptera: Sesiidae) Infestation of Apple Burrknots

Abstract

Dogwood borer, Synanthedon scitula (Harris), infestation of burrknot tissue on apple dwarfing rootstocks is an increasing problem throughout the northeastern United States. One insecticide, chlorpyrifos, is currently the only efficient chemical control available for dogwood borer. Because of scrutiny of chlorpyrifos under the US EPA's Food Quality Protection Act policy and the desire to increase options available to growers, we investigated other dogwood borer control options. Barriers to dogwood borer oviposition may offer an effective, efficient physical control. We tested 4 types of barriers including white latex paint, trunk wraps of spunbonded polyethylene fabric Tyvek® HomeWrap® (E. I. du Pont de Nemours and Company, Wilmington, DE) and self-adhesive veterinary gauze, and a sprayable, nonwoven ethylene vinyl acetate (EVA). These were compared with chlorpyrifos and an untreated check starting in late spring of 2006. All barriers were effective in preventing dogwood borer infestation and remained intact throughout the first growing season. The paint and EVA treatments persisted longer than other treatments. However, by March 2007, the paint treatment was beginning to fade and flake off. By May 2007 the EVA treatment was ≈ 95% (± 9.4%) intact, and trees were significantly less infested than trees in the paint treatment or an untreated check in September 2007. Whereas barriers were significantly less intact in the Tyvek and gauze treatments than in the EVA treatment in 2007, borer infestations were equivalent among treatments. EVA was the least costly of the barriers and its cost may be competitive with conventional chemical control.