松毛虫赤眼蜂对柞蚕灰卵的寄生选择与适应性

为明确柞蚕Antheraea pernyi灰卵(工厂化繁育赤眼蜂过程中广泛存在的一种感病寄主卵)对松毛虫赤眼蜂Trichogramma dendrolimi寄生选择与适应性及其繁育子代蜂寄生能力的影响,以柞蚕灰卵作为供试寄主,健康卵作为对照,在无选择和双向选择条件下研究松毛虫赤眼蜂对其的寄生选择与适应性,并比较灰卵和健康卵繁育的子代蜂对0、1、2、3日龄米蛾Corcyra cephalonica卵的寄生能力。结果表明,在无选择条件下,松毛虫赤眼蜂在灰卵上的寄生率、羽化率、单卵出蜂数和总蜂数分别为30.0%、54.1%、39.3头和48.7头,而在健康卵上分别达到96.0%、93.0%、82.5头和96.8头。在双向选择条件下,松毛虫赤眼蜂在灰卵上的寄生率、羽化率、单卵出蜂数和总蜂数分别为33.3%、27.1%、24.7头和52.2头,而在健康卵上分别为68.0%、86.3%、60.6头和74.2头。在无选择和双向选择条件下,松毛虫赤眼蜂在灰卵和健康卵上的发育历期和后代雌性比均不存在显著差异,但灰卵繁育的子代蜂对1、2日龄米蛾卵的寄生数则显著低于健康卵繁育的子代蜂,且后者对米蛾卵的寄生数随着米蛾卵日龄的增加呈逐渐下降趋势,而灰卵繁育的子代蜂对0、3日龄米蛾卵的寄生数要显著高于1、2日龄的。表明柞蚕灰卵会对松毛虫赤眼蜂的寄主选择与适应性以及子代蜂的寄生能力产生不良影响。

Parasitism and suitability of Trichogramma dendrolimi on the gray eggs of Chinese oak silkworm Antheraea pernyi

In order to clarify the influences of the gray eggs of Chinese oak silkworm Antheraea pernyi, a host egg susceptible to bacteria during massive production of Trichogramma dendrolimi, on the parasitism and performance of T. dendrolimi, the parasitism capacities of Trichogramma offspring reared by the gray eggs and healthy eggs were compared on 0-3-day-old eggs of the rice moth Corcyra cephalonica under no choice or paired choice conditions. The results showed that, under no choice conditions, the parasitism rate and emergence rate of T. dendrolimi on gray eggs, emerged wasps and total number of offspring per egg were 30.0%, 54.1%, 39.3 and 48.7, respectively. However, the parasitism rate and emergence rate on healthy eggs, emerged wasps and total number of offspring per egg reached 96.0%, 93.0%, 82.5 and 96.8, respectively. Under paired choice conditions, the parasitism rate and emergence rate of T. dendrolimi on gray eggs, emerged wasps and total number of offspring per egg were 33.3% and 27.1%, 24.7 and 52.2, respectively. However, the parasitism rate and emergence rate on healthy eggs, emerged wasps and total number of offspring per egg got to 68.0%, 86.3%, 60.6 and 74.2, respectively. There were no significant difference in developmental time and female progeny between gray eggs and healthy eggs regardless of the choice conditions. The offspring reared from healthy eggs significantly parasitized more eggs on 1- or 2-day-old eggs of C. cephalonica than that from gray eggs. The number of C. cephalonica eggs parasitized by the offspring reared from healthy eggs exhibited a decreasing tendency with increasing age of host eggs, but the offspring reared from gray eggs parasitized more 0- and 3-day eggs than 1- and 2-day eggs. The results indicated that the gray eggs of A. pernyi caused by bacteria could adversely affect the parasitism and performance of T. dendrolimi.