亞洲柑橘木蝨（半翅目：扁木蝨科）忌避劑之鑑定與開發

Abstract

亞洲柑橘木蝨 (Diaphorina citri) 是造成全世界柑橘樹黃化、減產、壽命降低的黃龍病 (Huanglongbing) 之病媒昆蟲。因目前尚未有方法能根治黃龍病，十分仰賴柑橘健康種苗、接穗、清園等方式預防。根據推拉技術，有效忌避劑與忌避作物的應用可降低害蟲接近農園的風險。本研究測試多種植物來源揮發物，逐一試驗其作為亞洲柑橘木蝨成蟲忌避劑成分之潛力。直接接觸寄主植物方面，以塑膠杯與月橘嫩枝設置非選擇性試驗，測試不同氣味之噴劑對亞洲柑橘木蝨成蟲取食的忌避效果。結果顯示，雖與對照組並無顯著差異，番茄、青蔥、薑、銀合歡萃取物、防蚊物質香茅油和檸檬桉醇 (PMD, p-menthane-3,8-diol) 皆具抑制亞洲柑橘木蝨停棲在寄主植物上的效果。以網箱及月橘嫩枝設置選擇性試驗結果則顯示，防蚊物質PMD單獨使用與和香茅油混用處理組，分別具忌避效果至試驗開始一天與一週後，枝條上之木蝨成蟲數量低於對照組。另一方面，以Y型管進行忌避性試驗說明：未直接接觸寄主植物以及樣品的狀況下，選擇3 g的番茄、銀合歡與月橘的破碎葉片揮發物端的亞洲柑橘木蝨成蟲數量低於選擇空白對照組。本研究更以氣相層析質譜技術鑑定忌避潛力樣品之揮發物組成分，結果顯示番茄剪碎葉片含有(E)-2 -己烯醛 (2-Hexenal, (E)-)、萘 (Naphthalene) 及β-石竹烯 (Caryophyllene) 等、月橘剪碎葉片揮發物則含β-石竹烯 (Caryophyllene)、薑烯 (α-Zingiberene)、香樹烯 (Alloaromadendrene) 等驅蟲化合物；市售檸檬桉香茅精油防蚊液之揮發物則主要以D-檸檬烯 (D-Limonene)、萘 (Naphthalene)、異胡薄荷醇 (Isopulegol) 與香茅醇 (Citronellol) 組成。本研究測試多種植物樣品，並且測試多種裝置在忌避劑開發過程的應用潛能。包含屬於農業廢棄物的番茄植株，以及政府大量移除收購的外來入侵種植物銀合歡。未來持續測試濃度與配方，將可創造附加價值，將研究成果應用於害蟲綜合防治策略、忌避劑配方開發、推拉技術實踐及環境友善農業。

The Asian citrus psyllid (Diaphorina citri) is the vector responsible for the global spread of Huanglongbing (HLB), a disease-causing yellowing, reduced yield, and decreased lifespan in citrus trees. This study aims to test various plant-derived volatile compounds for their potential as repellent components. In non-selective tests using plastic cups and tender jasmine orange branches, tomato, green onion, ginger, leucaena, citronella oil, and PMD were found have potential to inhibit psyllid settling on host plants. However, the effects were not significantly different from the control group. Selective tests in net cages revealed that PMD, used alone or in combination with citronella oil, exhibited repellent effects one day and one week after the experiment started, resulting in reduced psyllid numbers on the experimental groups. Y-tube olfactometer assays revealed that, without direct contact with samples, the number of adults on tomato, leucaena, and jasmine orange side were less than that on the blank control side. GC-MS analysis identified volatile compounds in tested samples. Tomato leaf extracts contain (E)-2-hexenal, naphthalene, and β-caryophyllene, while jasmine orange leaf extracts contain β-caryophyllene, zingiberene, and β-elemene of known insect-repelling compounds. The volatile components of commercially-available mosquito repellent primarily consist of D-limonene, naphthalene, Isopulegol, and citronellol. We explored various plant samples in this study, including agricultural waste like tomato plants and government-reclaimed invasive species like leucaena. Ongoing research will be focused on refining concentrations and formulations, aiming to enhance the efficacy of repellents in integrated pest management for Asian citrus psyllid and sustainable agriculture.