Field Evaluation of Melolure, a Formate Analogue of Cuelure, and Reassessment of Fruit Fly Species Trapped in Sydney, New South Wales, Australia

Abstract

In Australia, tephritids are usually attracted to either cuelure or methyl eugenol. Methyl eugenol is a very effective lure, but cuelure is less effective likely due to low volatility. A new formate analogue of cuelure, melolure, has increased volatility, resulting in improved efficacy with the melon fruit fly, Bactrocera cucurbitae Coquillett. We tested the efficacy of melolure with fruit fly species in Sydney as part of the National Exotic Fruit Fly Monitoring programme. This monitoring programme has 71 trap sites across Sydney, with each trap site comprising separate Lynfield traps containing either cuelure, methyl eugenol, or capilure lure. In 2008, an additional Lynfield trap with melolure plugs was added to seven sites. In 2009 and 2010, an additional Lynfield trap with melolure wicks was added to 11 trap sites and traps were monitored fortnightly for 2 yr. Capture rates for melolure traps were similar to cuelure traps for Dacus absonifacies (May) and Dacus aequalis (Coquillet), but melolure traps consistently caught fewer Bactrocera tryoni (Froggatt) than cuelure traps. However, trap sites with both a cuelure and melolure traps had increased capture rates for D. absonifacies and D. aequalis, and a marginally significant increase for B. tryoni. Melolure plugs were less effective than melolure wicks, but this effect may be related to lure concentration. The broader Bactrocera group species were attracted more to cuelure than melolure while the Dacus group species were attracted more to melolure than cuelure. There is no benefit in switching from cuelure to melolure to monitor B. tryoni, the most important fruit fly pest in Australia.

Raspberry Ketone Analogs: Vapour Pressure Measurements and Attractiveness to Queensland Fruit Fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae)

“…Because of the greater distance over which flies need to be attracted, differences in vapour pressure may yield stronger differences in capture efficacy when tested in field settings. A recent field study carried out in warm temperate conditions of New South Wales found no advantage in using ML rather than CL to monitor Q-fly [ 17 ]. However, another field study in tropical Queensland found that six Bactrocera species were significantly more attracted to ML than CL, including Q-fly and two other economically important species ( B .…”

“…ML has been reported to be around twice as effective as CL at attracting melon fly [ 9 , 12 , 14 , 15 ]. Even amongst the RK-responding Bactrocera , there are quite substantial differences in relative efficacy of RK analogs [ 16 , 17 ]. While positive effects for one RK-responding species can provide some general guidance, lures ultimately need to be tested for each species.…”

“…While positive effects for one RK-responding species can provide some general guidance, lures ultimately need to be tested for each species. Guided by the promising results for melon fly, several studies have considered ML as a potential Q-fly attractant [ 16 , 17 ]. One study, carried out in tropical conditions of North Queensland, found ML to be more effective than CL as a Q-fly lure [ 17 ], but another study, carried out in warm temperate areas of New South Wales, found ML to be less effective than CL [ 16 ].…”

Semiochemical mediated enhancement of males to complement sterile insect technique in management of the tephritid pest Bactrocera tryoni (Froggatt)

“…Studies of several Bactrocera species show that pre-release exposure of males to plant-derived semiochemicals and synthetic lures dramatically reduces their subsequent response to attractant lures used in MAT 20 , 21 . Several commercially available lures and other male attractants are known for B. tryoni , including cue-lure, melolure, raspberry ketone (RK), RK formate, RK trifluoroacetate, and zingerone, which are all structurally similar 11 , 15 , 22 – 25 . While RK and zingerone are naturally occurring, cue-lure, RK formate, and RK trifluoroacetate are synthetic analogues of RK 26 .…”