東方果實蠅產卵行為干擾之研究

Abstract

本研究目的為探討已被雌性東方果實蠅 (Bactrocera dorsalis) 產卵後之果實對其後續其他果實蠅雌蠅的產卵行為影響，並探討產卵忌避效果現象發生的原因。並針對會造成產卵忌避現象的果實分析其可能活性物質並以該活性物質成份進行生物性試驗，以開發東方果實蠅的新型防治資材以及防治策略，藉由此資材及防治策略之應用期能達到有效防治東方果實蠅且能有效減少化學藥劑之使用。試驗結果顯示番石榴經東方果實蠅產卵後會減少後續東方果實蠅進行產卵行為及產下的卵數，於選擇性試驗中產卵忌避指數可達 82.7%。由結果顯示東方果實蠅幼蟲糞便是主要影響東方果實蠅後續產卵行為之原因，以其糞便進行之選擇性試驗中發現產卵忌避指數可達68.2% 且具有劑量效應，以非選擇性方式的試驗結果，產卵忌避指數亦可達 53.0%。透過氣相層析質譜儀 (GC-MS) 分析東方果實蠅幼蟲糞便成分，其中 5-phenyl-1H-tetrazol (5-苯基四氮唑) 於人工產卵器的選擇性試驗中產卵忌避指數可達 47.0% 且具有劑量效應，直接施用5-phenyl-1H-tetrazol 溶液於番石榴果實的產卵忌避指數為 33.6%，產卵忌避指數降低的原因應為藥劑無法於番石榴果實上良好展著。於添加市售商品展著劑進行選擇性試驗，發現單獨使用 5 mg mL-1 展著劑Tween-20 亦有防治效果，其產卵忌避指數為 34.7%。以 5-phenyl-1H-tetrazol 混合 5 mg mL-1 Tween-20浸泡番石榴果實進行選擇性試驗，5-phenyl-1H-tetrazol 濃度 0.1 mg mL-1，產卵忌避指可達為 51.6%，於非選擇性試驗中 5-phenyl-1H-tetrazol 濃度 0.5 mg mL-1，其產卵忌避指數亦可達 30.1%，以 0.5 mg mL-1之 5-phenyl-1H-tetrazol 混合 5 mg mL-1 Tween-20 噴施 400 µL 於番石榴上，其產卵忌避指數可達 50.9%。本研究結果顯示東方果實幼蟲糞便中的 5-phenyl-1H-tetrazol 會影響干擾東方果實蠅之產卵行為。

The purpose of this study was to investigate the effects of oviposition affecting subsequent oviposition behavior of female Bactrocera dorsalis on the same fruit, and to search for the cause of this phenomenon. Subsequent analysis of active substances and biological tests are then used to further the development new control materials and stratagies for the prevention of B. dorsalis, while reducing the need for chemical pesticides.The results showed that oviposition of B. dorsalis on guava will reduce subsequent oviposition behavior and the number of deposited eggs of B. dorsalis. The oviposition deterrence index is 82.7%. Further experimentation showed that the feces of B. dorsalis larvae was the main cause of the reduction in oviposition behavior of B. dorsalis. In choice tests, the oviposition repellency index of the B. dorsalis larvae was 68.2% with dose dependency, and similar results were observed in non-choice test, with an oviposition deterrence index of 53%. Of the compounds found through GC-MS analysis of the B. dorsalis larvae, 5-phenyl-1H-tetrazol solution in choice tests using artificial ovipositor showed an oviposition deterrence index of 47.0% and was dose-dependent. The oviposition deterrence index using 5-phenyl-1H-tetrazol on guava fruits was 33.6%, which was due to the fact that the agent exhibited low adhesion on the guava fruit. Therefore, choice tests were performed using a surfactant commonly used in commercial products. It was found that the use of 5 mg mL-1 of Tween-20 also had a control effect, and its oviposition deterrence index was 34.7%. Follow-up tests will be performed with the combination of 5-phenyl-1H-tetrazol solution and Tween-20 at 5 mg mL-1. In choice tests using a soaking method of application can reduce the effective concentration of 5-phenyl-1H-tetrazol to 0.1 mg mL-1, with an oviposition deterrence index of 51.6%. For non-choice tests, the 5-phenyl-1H-tetrazol concentration was reduced to 0.5 mg mL-1 and the oviposition deterrence index was 30.1%.. Using a spraying method of application, the combination of 5-phenyl-1H-tetrazol at a concentration of 0.5 mg mL-1 and 5 mg mL-1 of Tween-20 was applied on guava with a volume of 400 μL, resulting in an oviposition deterrence index of 50.9%. Therefore, the results of the present study show that 5-phenyl-1H-tetrazol, a fecal component of the B. dorsalis larvae, can effectively affect the oviposition behavior of B. dorsalis.