可可椰子紅胸葉蟲寄生峰（Tetraslichus brontispae）之引進繁殖與釋放試驗

Abstract

本所於民國72年11月自關島引進可可椰子紅胸葉蟲(Brontispa longissima Gestr.)之蛹寄生蜂Tetrastichus brontispae Ferr．供可可椰子紅胸葉蟲之防治。該蜂引進本省後先在本所檢疫室進行檢疫、飼育以及生物特性等觀察。經繁殖3世代後即在高雄澄清湖與昇東林邊兩地釋放。農試所在室內飼育該蜂，發現其發育期之長短隨溫度之高低而有不同，於室溫20℃時，從卵發育至成蜂羽化，最短需17天，最長達32天。各蟲期分別爲卵期2-3天，幼蟲期5-6天，蛹期10-11天。平均雌蜂壽命約10.8天，雄蜂約3.6天。初步飼育觀察該蜂在室內之產卵寄生率平均為60.13±8.0%。T. brontispae蜂於民國72年1月18日開始，先俊10次釋放於澄清湖畔之椰樹林，至同年8月其寄生率爲18.8-79.2%。另於同年2月8日釋放於林邊，在3個月內釋放7次其寄生率爲9.3-44.2%。該蜂在兩地之釋放後均能寄生於紅胸葉蟲之蛹，順利繁衍，而發揮其生物防治效果，使受害之可可椰子樹逐漸恢復生機。本文報導該蜂之引進本省經過，室內增殖、部分生物特性觀察及其釋放於高、屏地區後，對可可椰子紅胸葉蟲棲羣之抑制效果。 The coconut tree, Cocos nucifera L., grown in the tropical and subtropical regions of the world, is the best known palm with high economic values. In Taiwan, it can be grown on the east coast and in areas south of Taichung on the west. The number of coconut trees planted in 1960 was estimated at 12,000 trees and was gradually increased to a total of 60,000 trees in 1984. The coconut leaf beetle, Brontispa longissima Gestro (Chrysomelidae), a serious pest of coconut trees, was first detected in Pingtung in July 1975. Since then, it has spread north to Taitung and then to Hualien. Since coconut trees are tall, reaching a height of 15-20 m., and are commonly planted along highways and around fish ponds, it renders the use of chemical pesticides for control of this pest economically impractical and environmentally unsafe. Therefore, the biological control approach was chosen as a viable alternative for solving this serious pest problem.