Cucumber Lure Trapping ofZeugodacus cucurbitae(Diptera: Tephritidae) in Hawaii and Taiwan: Longevity and Nontargets Captures

Abstract

The melon fly, Zeugodacus cucurbitae (Coquillett), is a serious pest of tropical horticulture, causing damage to cucurbits, tree fruits, and fruiting vegetables. Melon flies are especially attractive to freshly sliced cucumber, and this has led to the identification of a nine-compound kairomone lure that can be used to trap both female and male flies. In this study, a seven-compound lure, containing (Z)-6-nonenal, (Z)-6-nonen-1-ol, 1-octen-3-ol, (E,Z)-2,6-nonadienal, (E)-2-nonenal, hexanal, and 1-hexanol, was formulated into PVC plugs (100 or 300 mg/plug) for field testing in wet traps. In Hawaii, 100 mg of the seven-compound cucumber lure, loaded in either plugs or glass capillaries, attracted more flies than traps containing Solulys protein over a 9-wk period. However, both cucumber lure formulations showed marked declines in the number of flies trapped after 3 wk. Similar results were obtained during a 6-wk field trial using 100 mg cucumber lure plugs in Taiwan. Increasing the cucumber lure loading rate to 300 mg/lure increased the effective trapping life of the attractant during a second 9-wk field trial conducted in Hawaii. The synthetic cucumber lure showed female-biased sex ratios in trap captures in the Taiwanese and second Hawaiian field trials. Protein lures captures were female-biased in all three field trials. Wet traps in Hawaii containing the cucumber lure were found to capture 25-30 nontarget insects/trap/week, less than half that captured with Solulys. Captured nontarget insects represented 37 families in 10 orders. The most common families caught were Ceratopogonidae (∼9 flies/trap) and Gryllidae (∼7 crickets/trap).

Cucumber and Tomato Volatiles: Influence on Attraction in the Melon FlyZeugodacus cucurbitate(Diptera: Tephritidae)

“…This is consistent with previous studies in which blends of volatile organic compounds have been found to elicit strong attraction from insect herbivores. 11,38 However, these results suggest that the melon fly's attraction was not influenced by the ratio-specific odor representing the different host plant species. Instead the presence and nature of key components in the odor blend appeared to be important in host recognition as shown in our tests with single compounds, which revealed significant sex-and concentration-dependent variability in the melon fly responses to these compounds.…”

“…10 A more recent study using a blend comprising the seven compounds (Z)-6-nonenal, (Z)-6nonen-1-ol, 1-octen-3-ol, (E,Z)-2,6-nonadienal, (E)-2-nonenal, hexanal, and 1-hexanol loaded in PVC plugs or glass capillaries was found to be effective in trapping the melon fly. 11 Surprisingly, the role of host plant foliar and floral volatiles in attracting females of the melon fly has not been reported. In this decade, the melon fly has emerged as one of the most devastating pests of the solanaceous plant tomato, Solanum lycopersicum Mill, in eastern Africa.…”

Ridge gourd volatiles are attractive to gravid female melon fly, Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae)

“…Inopportunely, these lures lack potency, have restricted field life, are arduous to handle and attract non‐target species (Jang & Light, 1996). Presently, there are limited studies on female attractants of melon flies (Jang et al., 2017; Piñero et al., 2021; Shelly et al., 2017; Siderhurst & Jang, 2010) and there is a need for prospecting other host volatiles for alternative and possibly, better attractants.…”

“…studies on female attractants of melon flies (Jang et al, 2017;Piñero et al, 2021;Shelly et al, 2017;Siderhurst & Jang, 2010) and there is a need for prospecting other host volatiles for alternative and possibly, better attractants.…”

Cuticular Chemistry of the Queensland Fruit Fly Bactrocera tryoni (Froggatt)

“…Tephritid fruit flies are amongst the world’s most economically damaging insect pests [ 33 ]. Some aspects of tephritid fruit fly semiochemistry have received significant attention, particularly the pheromones [ 34 , 35 ] they use to attract mates and for aggregation and the particular compounds found in fruit, food and certain flowers to which they are attracted [ 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ]. Some work has also been performed on fruit fly cuticular chemistry because their cuticular chemical profiles tend to be highly species-specific [ 48 , 49 ] and have been used to resolve species, cryptic species and geographic variation in larvae [ 50 , 51 , 52 ] and adults [ 53 , 54 , 55 , 56 , 57 , 58 ].…”