寄主密度、寄生蜂密度和寄生蜂性比对麦蛾茧蜂繁殖的影响

Effects of the host density, parasitoid density, and parasitoid sex ratio on the mass rearing of Habrobracon hebetor (Hymenoptera: Braconidae)

麦蛾茧蜂是鳞翅目昆虫的一种外寄生蜂,是仓储鳞翅目害虫的重要寄生性天敌。为提高麦蛾茧蜂的扩繁效率,本文在室内条件下研究了其寄主烟草粉螟密度、麦蛾茧蜂密度和性比对其子代出蜂数(雌蜂数、雄蜂数和总蜂数)和雌雄性比的影响。结果表明,当烟草粉螟密度为5头/盒时,麦蛾茧蜂的子代出蜂雌蜂数、雄蜂数、总蜂数和雌雄性比最高,分别为(90.71±2.01)、(51.70±2.95)、(142.00±3.88)头和(1.79±0.11);当烟草粉螟密度为50头/盒而麦蛾茧蜂密度不同时,4对寄生蜂(蜂与害虫比为1∶12.5)的平均单雌出蜂数最高;此外,增加雌蜂数显著提高子代出蜂数,而增加雄蜂数并未显著影响这些指标。因此,本文推荐在麦蛾茧蜂的大量饲养中,按寄生蜂、害虫比为1∶5~1∶12.5、寄生蜂雌雄性比为1∶1的方式接蜂且可连续使用10 d,这将有利于麦蛾茧蜂的大量饲养。该研究结果可为麦蛾茧蜂的规模化繁育和应用提供技术参数。

Habrobracon hebetor(Say)(Hymenoptera: Braconidae) is a larval ectoparasitoid of numerous lepidopteran species, which was considered as the most important biological control agent against pests of stored grains. To improve the mass-rearing efficiency of H.hebetor, the effects of host Ephestia elutella(Hübner) density, parasitoid density, and the sex ratio of H.hebetor on the number of offspring wasps, offspring females, and offspring males, and sex ratio of H.hebetor offspring were studied under laboratory conditions. The results showed that the number of offspring females(90.71±2.01), offspring males(51.70±2.95), total offspring(142.00±3.88), and sex ratio of offspring(1.79±0.11) were the highest when five host individuals were supplied. When 50 host individuals were supplied at different densities of wasps, the number of offspring produced per female by four pairs of parasitic wasps(wasp∶host=1∶12.5) was the highest. Moreover, the number of offspring increased with increasing number of maternal female wasps, while increasing father wasps had no significant effect on the number of offspring. Therefore, it is recommended that the parental parasitoids should be introduced at a ratio of female to male of 1∶1 and a ratio of wasp to host of 1∶5-12.5 for 10 days, which is beneficial for the mass rearing of parasitoids. These results provide important technical parameters for the mass rearing and application of H.hebetor.