Capture of Zeugodacus cucurbitae (Diptera: Tephritidae) in Traps Baited with Torula Yeast Solution Versus Cucumber Volatile Plugs

Abstract

Several species of invasive fruit flies (Diptera: Tephritidae) are among the most damaging pests of agricultural crops in the world. Detection of these pests relies primarily on traps baited with male-specific lures. Traps with protein food baits are also employed to attract females, but these baits are fairly weak, and there is considerable interest in developing more powerful lures for female tephritids. Recently, a plug that emits cucumber volatiles was developed as a lure for cucurbit-infesting species, and a recent field study showed that traps baited with these plugs attracted more females of the Australian cucurbit pest Bactrocera cucumis (French) than traps containing a protein bait. The objective of the present study was to gather additional data regarding captures of a closely related species, the melon fly, Zeugodacus cucurbitae (Coquillett), in traps baited with a torula yeast and borax (TYB) solution (a standard food lure) compared with traps baited with the cucumber volatile (CV) plug. Data collected from 5 locations on Oahu, Hawaii, showed that traps baited with the TYB solution captured significantly more melon flies than traps baited with the CV plugs. At 4 sites, where hosts were scattered, melon fly captures were relatively low, and males were trapped in significantly greater numbers than females in both TYB- and CV-baited traps. At the remaining site, hosts were very abundant, melon fly captures were high, and females were trapped in significantly greater numbers than males in both TYB- and CV-baited traps. Possible explanations for the superior performance of TYB-baited traps are discussed.