Specialized pheromone and lure application technology as an alternative male annihilation technique to manage Bactrocera tryoni (Diptera: Tephritidae)

The results of this study suggest that a novel male annihilation technique (specialized pheromone and lure application technology [SPLAT] incorporating cue-lure [CL] plus spinosad) is as effective as industry standard male annihilation controls, and is worth exploring further to manage Bactrocera tryoni (Froggatt) populations. Three lures were evaluated in a contact and feeding bioassay and a cage attractancy trial: 1) SPLAT-CL + spinosad; 2) SPLAT-CL without spinosad; and 3) wick-CL + malathion. In a field attraction trial, lures (1) and (3) were evaluated with a third treatment, caneite blocks-CL + malathion. Lures were weathered for 0, 1, 2, 4, or 8 wk, with an additional weathering treatment of 12 wk included in the field trial. In the contact and feeding bioassay, lures with SPLAT-CL + spinosad were >97% effective at 48 h for up to 2 wk weathering; however, wicks-CL + malathion killed B. tryoni within 2 h of exposure under all weathering periods. In the cage attractancy trial, SPLAT-CL + spinosad was as effective as, or performed better than, wicks-CL + malathion under all weathering treatments. The field study trap catches were similar for SPLAT-CL + spinosad and blocks-CL + malathion, and both had higher trap catches than wicks-CL + malathion at all weathering periods, except week 12. Overall, SPLAT-CL + spinosad compared favorably with current standard techniques for male annihilation and warrants further research. SPLAT-CL + spinosad may be a reduced-risk alternative for wicks-CL + malathion or blocks-CL + malathion for B. tryoni and other CL-responding fruit flies, such as Bactrocera cucurbitae Coquillett, because it contains a reduced-risk insecticide that poses a lower risk to humans and the environment and does not require labor-intensive handling and placement.