西花蓟马孤雌产雄生殖繁育的后代种群生命表的建立

孤雌生殖是西花蓟马(Frankliniella occidentalis)繁殖的一种重要方式。前期研究发现,西花蓟马在高温下,雌性的存活率远大于雄性。为探究高温处理后仅有雌性西花蓟马孤雌产雄的情况下其后代建立种群的可能性,试验设定:高温(45℃,2 h)处理西花蓟马单个雌性个体,分别进行孤雌产雄生殖后,雄性子代(F1代)与其母系回交产生F2代;高温(45℃,2 h)处理西花蓟马多个雌性个体,进行孤雌产雄生殖后,雄性子代(F1代)与亲代多个雌性个体共存情况下进行交配产生F2代。两组处理模式下建立F2代实验种群生命表。结果表明,上述两种处理模式,母代雌性个体与子代雄性个体交配后均可产生后代,雄性F1代与其母系回交产生的F2代的雌雄性比为1.05∶1;与亲代多个雌性个体共存下交配产生的F2代性比为1.55∶1。雄性F1代与其母系回交产生的F2代的平均单雌产卵量(F)和内禀增长率(rm)显著小于与亲代多个雌性个体共存下交配产生的F2代(P0.05);各龄期的平均发育历期、平均产卵前期和平均总产卵前期2个繁殖力参数以及净生殖率(R0)、平均世代周期(T)2个种群参数,前者则比后者长(P0.05);另周限增长率(λ)两者之间无显著差异。研究表明西花蓟马在孤雌产雄状态下仍然可以在短期建立种群,具有较强的抗高温能力和繁殖能力,为其成功入侵奠定了生态学基础。

Population establishment of Frankliniella occidentalis (Thysanoptera: Thripidae) offspring under parental arrhenotocous parthenogenesis reproduction

The reproductive mode of parthenogenesis is critical for Frankliniella occidentalis (Thysanoptera: Thripidae) invasive species. Studies have shown that the survival of female thrips was significantly higher than that of male thrips at high temperature (45 ℃, 2 h). In order to explore the possibility of population establishment of western flower thrips by parthenogenesis under high temperature conditions, female adult thrips were exposed to 45 ℃ for 2 h and then their offspring (F1 generation) back-crossed with parental or “uncertain parental” female thrips. The life table was established to describe the population development of offspring after back-crossing (F2 generation). The results indicated that the above two modes of generation of female copulated with F1 male offspring both produced fertile offsprings. The sex ratio of the F2 generation from parental female adult (female︰male = 1.05︰1) was lower than the sex ratio of the F2 generation from “uncertain parental”female adults (female︰male = 1.55︰1). In addition, the F2 generation from parental female had lower average female fecundity (F, 44.25 eggs per female), lower intrinsic rate of increase (rm, 0.133 9), longer average developmental duration, longer adult pre-oviposition period (APOP, 3.13 d), longer total pre-oviposition period (TPOP, 17.19 d) and longer average generation duration (23.32 d) than the F2 generation from “uncertain parental” female adults (P < 0.05; F of 62.25 eggs per female, rm of 0.146 8, APOP of 2.85 d, TPOP of 14.45 d and longer generation duration of 20.49 d). However, no significant difference was noted in the finite rate of increase (P > 0.05). The results indicated that F. occidentalis established populations within a short time by arrhenotocous parthenogenesis and had strong resistance to high temperatures and reproductive capacity, which laid the basis for successful invasion. A single high temperature model was not ideal for the control of F. occidentalis in case of host plant without serious injuries. This suggested that multiple control modes were better. Future studies should investigate and discuss effective control modes of F. occidentalis.