寄生荔枝蒂蛀虫卵的斑螟分索赤眼蜂过寄生驯化培育

Domesticated Breeding of Trichogramma Parasitizing Eggs of Conopomorpha sinensis Bradley

针对寄生荔枝蒂蛀虫卵的斑螟分索赤眼蜂Trichogrammatoidea hypsipylae Nagaraja不能正常羽化出蜂问题,室内以米蛾Corcyra cephalonia(Stainton)卵为寄主,分别以1:3、1:5、1:10(对照)的蜂卵比接蜂培养,经过35代过寄生连代繁殖驯化,其36代(F36)成蜂个体大小显著小于对照组。与对照组相比,成蜂体长、体宽分别减小28.89%、16.08%(1:3处理)和27.43%、20.56%(1:5处理)。经蜂卵1:3、1:5接蜂连代繁殖驯化后的F36斑螟分索赤眼蜂对荔枝蒂蛀虫卵的寄生率分别为44%和55%,与对照差异不显著,但能顺利从荔枝蒂蛀虫卵内羽化出蜂,羽化率分别为31.8%、25.5%,对照则无羽化出蜂。表明通过过寄生驯化培育可以改变斑螟分索赤眼蜂的个体大小,并有望使其在荔枝园内建立稳定种群,达到持续控制荔枝蒂蛀虫的目的。

Trichogrammatoidea hypsipylae Nagaraja, an indigenous natural egg parasitoid of Conopomorpha sinensis Bradley in South China, has been identified as the most suitable candidate to control C. sinensis in laboratory studies in recent years. However, the wasp cannot emerge from the parasitized eggs of C. sinensis. In the present study, the parasitoids were domesticated for 35 generations on eggs of Corcyra cephalonica Stainton in the laboratory under three parasitoid to host ratio, 1 ： 3, 1 ： 5, and 1 ： 10. Results showed that the wasps of the 36th generations in the low host density groups were significantly smaller than those in the control group （parasitoid：host ratio= 1 ： 10）. As compared with the wasps in 1 ： 10 groups, body length and width in the 1 ： 3 group were reduced by 28.89% and 16.08%, respectively, and in the 1 ： 5 group, reduced by 27.43% and 20.56%, respectively. Parasitism rates were not different in the wasps domesticated at the parasitoid to host ratios of 1：3 （44%）, 1：5 （55%） and 1 ： 10 （59%）. However, T. hypsipylae in the low host density groups could emerge successfully, and emergence rates were 31.8% （1：3 group） and 25.5% （1：5 group）, respectively; while no wasp emergence was observed in the control group （1 ： 10）. These results reveal that domesticated breeding can reduce the body size of T. hypsipylae, which will establish stable populations of the wasp in litchi orchards and sustain sustainable control of C. sinensis.