Acetophenone and Green Leaf Volatiles Do Not Enhance the Efficacy of Verbenone for Inhibiting Attraction of Ips pini (Coleoptera: Curculionidae) to Pheromone-baited Traps in Northern Arizona

We assessed attraction of pine engraver, Ips pini (Say) (Coleoptera: Curculionidae; Scolytinae), to pheromone-baited funnel traps treated with repellent semiochemicals in ponderosa pine, Pinus ponderosa var. scopulorum Engelm., forests in northern Arizona. Treatments included: 1) baited control (B, ipsdienol + lanierone), 2) 70 g of SPLAT Verb (a flowable, biodegradable formulation containing 10% verbenone, ISCA Technologies Inc., Riverside, CA, USA) + B, 3) 70 g of SPLAT Verb + (E)-2-hexen-1-ol+(Z)-2-hexen-1-ol + acetophenone + B, 4) 7.84-g verbenone pouch (Product #3413, Synergy Semiochemicals Corp., Delta, British Columbia, Canada) + B, and 5) 7.84-g verbenone pouch + (E)-2-hexen-1-ol+(Z)-2-hexen-1-ol + acetophenone + B. In total, 472 I. pini were collected. Trap catches were highest in baited traps and declined significantly with the addition of both formulations of verbenone. Traps treated with SPLAT Verb caught significantly fewer I. pini and male I. pini than those treated with verbenone pouches. The addition of (E)-2-hexen-1-ol+(Z)-2-hexen-1-ol + acetophenone to SPLAT Verb and the verbenone pouch had no effect on trap catch. Verbenone has potential as an effective tool for protecting P. ponderosa trees and slash from I. pini in northern Arizona, but the addition of (E)-2-hexen-1-ol+(Z)-2-hexen-1-ol + acetophenone to verbenone is unwarranted.