天敵的遺傳改良

Abstract

生物防治中，天敵常不能達成壓制害蟲族群的任務。經由在遺傳上改良天敵或可改善此問題，已有一些利用育種來改進天敵、性比、對不同溫度的適應性及抗藥性的研究。其中最成功的當數西方捕植蟎經抗多種農藥品系的篩選培育。釋放於田間後此抗性捕植蟎品系能在田間立足、持續、並成功發揮抑制葉蟎族群之功能“此外，更在該捕植蜻成功地進行了基因轉殖測試。本文簡介了有關的研究工作。臺灣亦在進行生物防治工作，宜監測大量繁殖的天敵有無不良變異、選育高生殖能力的品系以助益於天敵的大量繁殖、或是培育適於在不同作物或不同季節釋放的天敵品系。而抗藥性之天敵的選育可能為目前最值得進行的工作。在短期作物上，經遺傳改良之天敵在釋放後能持續至作物收割後即可，長期持續之能力或非必要。 The natural enemies often failed to suppress the pest population. This may be enhanced through genetic improvement on the natural enemies. A few works were carried on the breeding of strains of various natural enemies to improve their fecundity, sex ratio, tolerance to various temperatures, and pesticide resistance. Among these works the selection of multipesticide-resistant strain of Metaseiulus occidentalis (Nesbitt) was most prolific. Released into fields, it survived, persisted, and reduced the spider mite population. In addition, genetic transformation was carried successfully on this mite. These works were briefly introduced. Biological control works have been conducted in Taiwan. It is worthwhile to probe the quality of the mass-reared natural enemies, to improve the fecundity to facilitate the mass-production of natural enemy, to breed strains for the release in various crops or seasons. Currently the selection of pesticide- resistant strain is probably most worthwhile. When crops are harvested within a few months after cultivating, genetic improved strain of natural enemy only needs to last out the harvest for using on these crops. The ability of long-term persistence may not be necessary.