New Chemical Attractants for Yellow Jackets (Vespula Spp.)

Abstract

Of 102 synthetic organic compounds tested in Oregon in 1966 as attractants for yellow jackets (Vespula spp.), 82 caught 1 or more specimens, and 7 were more attractive than the standard, 2,4-hexadienyl butyrate. The compounds were tested by placing about 0.25 ml in the bottom of straight-sided 0.473-liter glass jars equipped with inverted screen cones having a 1.27-cm-diameter hole at the apex of the cone. Insects responding to the lures entered the holes in the cones and were unable to escape from the traps. The most effective compounds were esters of α,β-unsaturated acids. All of the thousands of yellow jackets trapped in the Willamette Valley of Oregon were Vespula pensylvanica (Saussure). Three other species, V. atropilosa (Sladen), V. acadica (Sladen), and V. vulgaris (L.), were caught elsewhere and at higher elevations in various parts of the State. The attractants appeared to be highly specific for yellow jackets, since few other insects and no beneficial species such as honey bees, Apis mellifera L., were caught.