Ms Jodie Cheesman1, Mr Stefano de Faveri1, Ms Mai Nantawan1, Professor Matthew Siderhurst2, Dr R Andrew Hayes3

1Queensland Department of Agriculture and Fisheries, Mareeba, Australia, 2United States Department of Agriculture, Hilo, USA, 3University of the Sunshine Coast, Dutton Park, Australia

Biography:

Dr Andrew Hayes is a Forest Health Senior Research Fellow in the Forest Research Institute at the University of the Sunshine Coast, Queensland, Australia. He began his research career investigating the signals used to maintain social status in wild European rabbits (Oryctolagus cuniculus). After completing his PhD, he stayed within the field of vertebrate chemical ecology, studying signals linked to genetic relatedness in lemurs (Propithecus edwardsii), response to predator odours in Australian native rats (Uromys, Melomys and Rattus) and inter-specific signals in the invasive cane toad (Bufo marinus). Since 2008 Andrew’s interests have moved to insect chemical ecology, where his research now focuses on control and monitoring tools for insect pests of horticultural crops and forestry plantations.

Abstract:

A nine-component synthetic lure based on cucumbers was developed as an attractant for the melon fly Zeugodacus curcubitae. The commercially available form of this lure has only seven components. The commercial lure was found to attract the cucumber fruit fly, Z. cucumis, a horticulturally important pest in Australia for which there is no known male lure. This study investigated optimisation of this lure by subtraction bioassay and/or by addition of new compounds from other attractive fruits. Zeugodacus cucumis is electrophysiologically active to all the original nine components when tested individually, and to both the nine- and seven-component blends.

Subtraction bioassays show different preferred lures based on fly species. In the USA, bioassays showed the nine-component lure is better in attracting Z. cucurbitae. In Australia, Z. cucumis attraction was not different between seven- and nine-component lures.

Volatiles were analysed from several additional cucurbits known to attract Z. cucumis. Two Luffa spp. were largely similar in compounds identified and overall relative abundances, but new compounds identified are potentially metabolites from the lipoxygenase (LOX) pathway. Further evidence for adding Luffa volatiles to the existing cucumber lure was found when these volatiles elicited strong EAG responses from Z. cucumis.

Field testing of multiple lures to date has been constrained by an unexpected drop in the size of field populations of Z. cucumis. Given the promising EAG results with Z. cucumis, we suggest that LOX pathway volatiles identified from Luffa species may increase the attraction of Z. cucumis if added to the seven-component lure.