USDA-APHIS, 41-650 Ahiki Street, Waimanalo, HI 96795, USA.
J Insect Sci. 2010;10:8. doi: 10.1673/031.010.0801.
The sterile insect technique may be implemented to control populations of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), when environmental concerns preclude widespread use of chemical attractants or toxicants. The goal of the present study was to evaluate whether the mating competitiveness of sterile B. dorsalis males could be increased via pre-release feeding on methyl eugenol. Males of the oriental fruit fly are strongly attracted to this plant-borne compound, which they ingest and use in the synthesis of the sex pheromone. Previous studies conducted in the laboratory and small field-cages have shown that males given methyl eugenol produce a more attractive pheromone for females and have a higher mating success rate than males denied methyl eugenol. Here, levels of egg sterility were compared following the release of wild-like flies and either methyl eugenol-fed (treated) or methyl eugenol-deprived (control) sterile males in large field enclosures at four over flooding ratios ranging from 5:1 to 60:1 (sterile: wild-like males). Treated sterile males were fed methyl eugenol for 1-4 h (depending on the over flooding ratio tested) 3 d prior to release. Eggs were dissected from introduced fruits (apples), incubated in the laboratory, and scored for hatch rate. The effect of methyl eugenol was most pronounced at lower over flooding ratios. At the 5:1 and 10:1 over flooding ratios, the level of egg sterility observed for treated, sterile males was significantly greater than that observed for control, sterile males. In addition, the incidence of egg sterility reported for treated sterile males at these lower over flooding ratios was similar to that noted for treated or control sterile males at the 30:1 or 60:1 over flooding ratios. This latter result, in particular, suggests that pre-release feeding on methyl eugenol allows for a reduction in the number of sterile flies that are produced and released, thus increasing the cost-effectiveness of the sterile insect technique.
利用不育昆虫技术控制东方果实蝇种群时，如果环境问题不允许广泛使用化学引诱剂或有毒物质，则可以采用该技术。本研究的目的是评估在释放之前用甲基丁香酚喂养是否可以提高不育的东方果实蝇雄蝇的交配竞争力。这种植物源性化合物对东方果实蝇雄蝇有很强的吸引力，雄蝇会摄取并将其用于合成性信息素。先前在实验室和小型田间笼中进行的研究表明，给予甲基丁香酚的雄蝇会产生对雌蝇更有吸引力的信息素，并且比拒绝甲基丁香酚的雄蝇具有更高的交配成功率。在这里，在四个淹没比（从 5:1 到 60:1（不育：野生型雄蝇））的大型田间围栏中释放类似于野生的蝇种后，比较了释放经过甲基丁香酚喂养（处理）或未经过甲基丁香酚喂养（对照）的不育雄蝇的卵不育水平。在释放前 3 天，根据测试的淹没比，用甲基丁香酚处理不育雄蝇 1-4 小时（取决于测试的淹没比）。从引入的果实（苹果）中解剖卵，在实验室中孵化，并计算孵化率。在较低的淹没比下，甲基丁香酚的作用最为明显。在 5:1 和 10:1 的淹没比下，处理过的不育雄蝇的卵不育水平明显高于对照不育雄蝇。此外，在较低的淹没比下，报告的处理过的不育雄蝇的卵不育率与在 30:1 或 60:1 的淹没比下报告的处理过或对照不育雄蝇的卵不育率相似。特别是后一个结果表明，在释放之前用甲基丁香酚喂养可以减少生产和释放的不育蝇的数量，从而提高不育昆虫技术的成本效益。
