Brunner, Jay F.

Gut, Larry J.

Undetermined

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1. Thresholds/Monitoring/SamplingMONITORING CODLING MOTH IN PHEROMONE-TREATED ORCHARDS:COMPARISON OF LURESLarry J. Gut and Jay F. BrunnerWashington State UniversityTree Fruit Research and Extension CenterWenatchee, WA 98801Pheromone traps baited with a high load-rate red septum (10 mg of codlemone) have beenadopted as a tool for monitoring codling moth (CM) in mating disruption (MD) orchards. Thistrapping system can be used to track CM flight and to determine the need for supplementaltreatments of pheromone or conventional insecticides where MD is failing to control CM.However, the reliability of a 10 mg lure-baited trap to indicate the potential for fruit injury inMD orchards is not as good as growers and crops consultants would like. Here we report oncontinuing efforts to develop more effective high load CM trapping systems.Three kinds of experimental high load lures were tested: a biolure (Consep, Inc.), a bubble cap(Pherotech, Inc.) and a plastic resin (Scenturion, Inc.). All lures were engineered to release 5-10|ig of codlemone per hour. This emission rate was targeted because previous studies indicated ahigh degree of attractancy of the 10 mg red septa releasing these quantities of pheromone. Wedirectly compared the attractancy of the three experimental lures and the commercially availablered septum loaded with 10 mg of codlemone (Trece, Inc.). The experimental design was arandomized complete block. Tests were conducted in 6 pheromone-treated blocks (Isomate CPlus at 400 dispensers/acre) at the Tree Fruit Research Center. The number of male mothscaptured in Delta traps (Scenturion, Inc.) baited with the different lures was recorded every 2-3days. To minimize position effects, traps were rotated each time they were inspected. Red septalures were replaced after three complete rotations (27 days) during the first generation flight andafter two rotations (18 days) during the second generation flight. Trap bottoms were replacedafter a cumulative catch of 30 moths, more often if dirty.The relative attractancy of the various high load lures during the first and second generationflights of CM are shown in Figures 1A & IB. Data are presented as the average capture ofmoths in traps baited with different lures over the course of 9 days. Each successive 9 daytrapping period corresponded to a complete cycle of trap rotations. The experimental high loadlures engineered by Pherotech and Consep were the most effective lures. They were as attractiveas the commercial standard, a 10 mg red septum, and maintained their attractancy for a longerperiod of time. The Pherotech bubble cap had the greatest longevity, maintaining a high level ofattractancy without replacement for 54 days of each CM flight. The Consep biolure performedwell for approximately 27 days during the first and second generation flights. In contrast, asignificant reduction in the relative attractancy of the red septum was observed after 9 days offield-aging during the first flight. The relative attractancy of the red septum increased followingits replacement on day 27. Moth captures in traps baited with new septa or aged bubble capswere not significantly different during the next 9 day test period (day 36, Fig. 1A). However, therelative attractancy of the red serum declined over the next 18 days of trapping. Maintaining alevel of attractancy for the red septa equivalent to that of the bubble cap throughout the secondgeneration flight was achieved by shortening the replacement interval for the red septum to 18days. The experimental high load lure engineered by Scenturion did not perform wellthroughout the first generation flight. However, modification of the lure by the manufacturerprior to the second generation tests improved its attractancy. During the second flight, this lureperformed as well as the Consep biolure.2130.0 -i30.0 -i^ Trece 10Xn Consep0 Pherotech• Scenturion18 27 36 54Days after trap placementj—I new 10X• Trece 10Xn ConsepH Pherotech• Scenturion18 27 36 54Days after trap placementAllAllFigure 1.Firstgeneration (A)andsecond generation (B)capture of CMmales inpheromone trapsbaitedvarioustypesof highload lures. Means followed bydifferent letters are significantly different(P<0.05)according to Fisher's ProtectedLSD. Trece 10Xlures werereplaced as indicated (new 10X),all otherlures were not replaced throughout each 54 day testing period.22

Monitoring codling moth in pheromone-treated orchards : comparison of lures

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Monitoring codling moth in pheromone-treated orchards : comparison of lures

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