L. K. Tanigoshi and J. R. Bergen
Washington State University
Vancouver Research and Extension Unit
Vancouver, WA 98665-9752
Strawberry crown moth (SCM), Synanthedon biblionipennis, was collected on 11 July 2005 near Richfield, WA in a 1 year-old ‘Totem’ field. Adults were collected with pheromone lures, sweep nets and plastic cups. Collections were taken to the lab and prepared for exposure to 3 experimental compounds and compared with field rates of Actara (thiamethoxam), Capture (bifenthrin) and Entrust (spinosad). Leaflets were individually placed in small water-filled vials plugged with cotton and sprayed with 1 ml of each treatment with a Precision Potter Tower. Each air dried leaf was placed in 5.5 oz. plastic cup with one strawberry crown moth. The plastic lid was perforated and mortality examined daily for 3 days. Ten moths were used for each treatment on 12 July.
The neonicotinoids Actara and Assail (acetamiprid) provided comparable knockdown with our standard Capture and experimental Mustang Max (zeta-cypermethrin) from 1-3 days posttreatment. Because of high-untreated check mortality, the trial was stopped after 3 days.
These population trends were similar to the 2 trials we reported last year and again high SCM mortality occurred after 3 days incarceration in our cup arenas. The mortality trends for the experimental Avaunt was similar to last year’s results, with > 90% occurring around 5 days posttreatment. The lower rate of the organic formulation of spinosad, Entrust, did not perform to the 0.094 lb(AI)/acre level recommended for Success 2SC in strawberry. We are recommending spinosad for SCM control during the harvest period in strawberry. Its chemistry will enhance resistance management for SCM and worm control in rotation with Thiodan, Brigade/Capture and Lorsban.
Treatment | lb(AI)/acre | Percent Mortality | ||
---|---|---|---|---|
1DAT | 2DAT | 3DAT | ||
Means within columns followed by the same letter are not significantly different (Tukey HSD test P<0.05). | ||||
Actara 25 WG | 0.06 | 90a | 90a | 90a |
Assail 70WP | 0.05 | 40ab | 90a | 90a |
Avaunt TM | 0.11 | 50ab | 60a | 70a |
Capture 2EC | 0.1 | 90a | 90a | 90a |
Mustang Max | 0.03 | 80a | 90a | 100a |
Entrust | 0.08 | 40ab | 60a | 80a |
Untreated check | 0b | 10b | 20a |