Department of Chemistry, Eastern Mennonite University, Harrisonburg, VA.
Tropical Crop and Commodity Protection Research Unit, USDA-ARS, Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center, Nowelo St. Hilo, HI.
J Econ Entomol. 2019 May 22;112(3):1306-1313. doi: 10.1093/jee/toz006.
Melon fly, Zeugodacus cucurbitae (Coquillett), is a serious pest of tropical horticulture, causing damage to cucurbits, other fruiting vegetables, and certain tree fruits. The deployment of male lures comprises an important component of several detection and control strategies for this pest, with the main male attractant currently in use being cuelure (CL). A novel fluorinated analog of CL, raspberry ketone trifluoroacetate (RKTA), has been developed for the control of Bactrocera tryoni, a related pest; here, we test this compound for attraction to Z. cucurbitae. In outdoor screen cage testing, observations showed both more flies on filter papers, and a higher percentage of flies feeding, on papers treated with RKTA than on those with CL or melolure (ML). Field trapping with both yellow sticky traps and bucket traps found that RKTA captured more flies during the first 6 h of trapping than CL, while trap captures in the subsequent 18 h did not differ between the two lures. When comparing combined 24 h trap captures, yellow sticky traps containing RKTA captured more flies than those with CL, while bucket trap captures did not vary by lure. Analysis of lures weathered on filter paper found that nearly all applied RKTA hydrolyzed to RK within 6 h. Fine-scale melon fly behaviors digitally recorded in the field showed median resting distances from the lure of responding flies were shorter for RKTA than for CL. This study demonstrates the inherent attractiveness of RKTA while also highlighting the instability of this compound due to hydrolysis.
瓜实蝇，Zeugodacus cucurbitae (Coquillett)，是热带园艺的严重害虫，对瓜类、其他结果蔬菜和某些核果造成损害。雄性诱饵的部署是该害虫几种检测和控制策略的重要组成部分，目前主要使用的雄性引诱剂是瓜实蝇引诱剂 (CL)。一种新型的 CL 氟代类似物，覆盆子酮三氟乙酸酯 (RKTA)，已被开发用于控制相关害虫桃小食心虫；在这里，我们测试该化合物对 Z. cucurbitae 的吸引力。在户外屏幕笼测试中，观察结果表明，用 RKTA 处理的滤纸吸引了更多的苍蝇，并且有更高比例的苍蝇在滤纸上取食，而用 CL 或瓜实蝇引诱剂 (ML) 处理的滤纸则不然。使用黄色粘性陷阱和桶形陷阱进行田间诱捕发现，在诱捕的前 6 小时内，RKTA 比 CL 捕获了更多的苍蝇，而在随后的 18 小时内，两种诱饵的诱捕量没有差异。当比较 24 小时的总诱捕量时，含有 RKTA 的黄色粘性陷阱捕获的苍蝇比含有 CL 的陷阱多，而桶形陷阱的捕获量则没有因诱饵而异。对滤纸风化的引诱剂进行分析发现，在 6 小时内，几乎所有施加的 RKTA 都水解为 RK。在野外记录的瓜实蝇精细行为分析中，反应蝇从诱饵的平均休息距离比 CL 更短。本研究证明了 RKTA 的固有吸引力，同时也强调了由于水解作用，该化合物的不稳定性。
