Control of Grape Root Borer (Lepidoptera: Sesiidae) by Mating Disruption with Two Synthetic Sex Pheromone Compounds

Abstract

The pheromone ( E,Z )-2,13-octadecadien-1 ol acetate [called ( E,Z )-2,13-ODDA] or ( Z,Z )-3,13-octadecadien-1 ol acetate [called ( Z,Z )-3,13-ODDA; the main component of the peachtree borer, Synanthedon exitiosa (Say), sex pheromone and mating disruption dispenser] was released into the air from Shin-Etsu ropes (254 per hectare [100 per acre]) in whole bunch grape vineyards and compared with untreated vineyards using a randomized block design (four replicates). Pherocon IC traps baited with a 99:1 blend of ( E,Z )-2,13-ODDA:( Z,Z )-3,13-ODDA were used to monitor the seasonal number of grape root borer males, Vitacea polistiformis (Harris). These trap captures were significantly reduced by 99.1 and 87.5% in the vineyards treated with ( E,Z )-2,13-ODDA and ( Z,Z )-3,13-ODDA, respectively, compared with the untreated vineyard mean capture of 134.0 males. The ( Z,Z )-3,13-ODDA-treated vineyards realized a mean grape root borer pupal skin reduction of 92.7% over a 2-yr period (life cycle), which was significantly different than the mean count from the untreated vineyards (17.2% increase). The mean pupal skin count reduction of 65.7% from the ( E,Z )-2,13-ODDA-treated vineyards was not significantly different from either the ( Z,Z )-3,13-ODDA-treated or untreated vineyards. This lower mean reduction was attributed to only one ( E,Z )-2,13-ODDA-treated vineyard that probably experienced immigration of mated feral females from an untreated vineyard 200 m to the southwest. It appears that placement of 254 ties per hectare per season of either compound alone in isolated vineyards with a low to moderate population of grape root borers may be an effective and environmentally safe alternative to insecticide treatments for control of the grape root borer.