5种赤眼蜂对红脉穗螟卵的寄生力比较

红脉穗螟Tirathaba rufivena (Walker)]是槟榔的重要害虫,为筛选有效防治红脉穗螟的优势赤眼蜂蜂种,研究比较了稻螟赤眼蜂、食胚赤眼蜂、松毛虫赤眼蜂、玉米螟赤眼蜂和螟黄赤眼蜂对红脉穗螟的寄生力。结果表明,在一定的寄主卵密度范围内,稻螟赤眼蜂、松毛虫赤眼蜂和食胚赤眼蜂对红脉穗螟卵的寄生数量随着红脉穗螟卵密度的增加而逐渐增加,其中,稻螟赤眼蜂、松毛虫赤眼蜂和食胚赤眼蜂在红脉穗螟的卵密度分别为35、30和25粒/管,寄生卵数量和寄生率均为最大,寄生卵数量分别为16.2、8.8和10.6粒,寄生率分别为46.3%、29.3%和42.4%。在赤眼蜂羽化后的12 h内,在0~72 h提供充足卵的情况下,食胚赤眼蜂、稻螟赤眼蜂和松毛虫赤眼蜂主要在0~24 h寄生红脉穗螟的卵,分别占总寄生量84.8%、48.6%和60.7%,其子代蜂总数分别为48.5、50.8和53.8头,子代雌蜂比例分别为68.2%、74.4%和55.1%。结果表明稻螟赤眼蜂对红脉穗螟卵具有较强的寄生能力,松毛虫赤眼蜂和食胚赤眼蜂作为红脉穗螟卵补充优势赤眼蜂,这3种赤眼蜂可共同防治红脉穗螟。

Parasitic Capacity of Five Trichogramma Species to Eggs of Tirathaba rufivena

Tirathaba rufivena Walker (Lepidoptera: Pyralidae) is a destructive pest of areca palm, Areca catechu L. (Arecaceae), in China. In order to screen out dominant Trichogramma species for their effectiveness in controlling this pest, the parasitism capacity of T. japonicum Ashmead, T. dendrolimi Matsumura, T. embryophagum Harti, T. chilonis Ishii, and T. ostriniae Pang et Chen, on T. rufivena eggs at different densities was investigated in this study. The number of parasitized eggs by T. japonicum, T. dendrolimi, and T. embryophagum increased with the increasing density of the T. rufivena eggs within a certain density levels. At a host density of 35, 30 and 25 eggs/tube (Volume=84.8 cm ³) for T. japonicum, T. dendrolimi and T. embryophagum, respectively, the number of parasitized eggs and parasitism rate was the highest. The number of parasitized eggs was 16.2, 8.8 and 10.6, respectively, parasitism rate was 46.3%, 29.3% and 42.4%, respectively. Trichogramma species less than 12 h old were provided with adequate eggs of T. rufivena within 72 h, most of host eggs were parasitized by T. japonicum, T. dendrolimi and T. embryophagum during the period of 0 to 24 h. The parasitism proportion was 84.8%, 48.6% and 60.7% respectively. The number of offspring was 48.5, 50.8 and 53.8 individuals, respectively. Percentage of female progeny was 68.2%, 74.4% and 55.1%, respectively. It indicated that T. japonicum have a strong parasitic ability to the eggs of T. rufivena. T. japonicum, T. dendrolimi and T. embryophagum could be used as the dominant Trichogramma species for controlling T. rufivena.