Field Capture of Male Melon Flies, Bactrocera cucurbitae (Coquillett), in Jackson Traps Baited with Cue-Lure Versus Raspberry Ketone Formate in Hawaii

Abstract

The melon fly, Bactrocera cucurbitae (Coquillett), is an invasive worldwide pest of vegetables, particularly various species of squashes and melons. Because it poses a serious economic threat, many countries operate continuous trapping programs to detect incipient infestations. Detection currently relies on traps baited with a chemical (cue-lure, CL) that is attractive to males of this species. Earlier research suggested that a chemically similar compound (raspberry ketone formate, RKF) is more attractive than CL and thus might improve surveillance efforts. The present study describes the results of field experiments in Hawaii that compare captures of B. cucurbitae males in traps baited with (1) CL liquid versus a solid formulation (so-called plugs) of RKF or (2) CL liquid versus RKF liquid. In the first experiment, the traps with CL liquid captured more males than traps baited with RKF plugs in three of the four study sites, with no difference observed between lures at the remaining area. In the second experiment, the traps baited with CL liquid captured more males than traps baited with RKF liquid at two of the four study areas, with no difference observed between lures at the remaining two sites. The discrepancy between earlier studies and the present one highlights the need for additional field testing of RKF to assess its value as a replacement for CL.