蠋蝽猎物—黏虫的室内种群复壮

Population rejuvenation of Mythimna separata,a prey of the important natural enemy Arma chinensis

猎物的质量直接决定了天敌的质量和饲养规模。蠋蝽是一种重要的捕食性天敌,其若虫和成虫对鳞翅目害虫幼虫均有较强的捕食能力。目前蠋蝽主要依靠黏虫来饲养。但在长期室内饲养过程中黏虫种群出现衰退现象,进而制约了蠋蝽规模化繁育。本文旨在研究黏虫种群复壮措施,为蠋蝽的规模化繁育提供技术支撑。为此,采用回接自然寄主和室内与室外种群杂交的方式评价了黏虫的种群复壮效果。结果表明,回接自然寄主玉米叶后黏虫的幼虫发育历期(18.03 d)较人工饲料饲养组(21.26 d)显著缩短,蛹重(369.00 mg)和成虫产卵量(770.88粒/雌)显著高于人工饲料饲养组(323.56 mg,532.73粒/雌),但二者的蛹历期和成虫寿命无显著差异。杂交试验结果表明,4种交配方式产生的F_(1)代产卵前期、雌雄成虫寿命及其子代幼虫和蛹的发育历期无显著差异,但产卵期、产卵量及蛹重存在差异。其中以田间雌性×田间雄性(YF×YM)组合的产卵期最长(8.07 d)和产卵量最高(938.77粒/雌),而以田间雌性×室内雄性(YF×EM)组合的蛹最重(354.59 mg)。这些结果显示,通过回接自然寄主和室内与室外种群杂交的方式能促进黏虫的种群复壮。

The quality of prey directly determines the quality and rearing scale of natural enemies.Arma chinensis is an important predator,and its nymph and adult can predate the larvae of many Lepidoptera species.Until now,rearing of A.chinensis mainly depends on Mythimna separata,an economically important pest of grain crops in China.However,the population quality of this prey decreases after successive generations,and thus restrict large-scale rearing of A.chinensis.This study aimed to resolve the issue of quality degradation of M.separata population,and further provide a theoretical support for large-scale rearing of A.chinensis.The effects of population rejuvenation of M.separata was evaluated by providing the natural host and hybridization between indoor and outdoor populations.The results showed that the developmental duration(18.03 d)of larvae feeding corn leaves was significantly shorter than that of the artificial diet group(21.26 d),the pupal weight(369.00 mg)and the number of eggs laid by female adults(770.88 eggs per female)were significantly higher than that of the artificial diet group(323.56 mg,532.73 eggs per female);however,no significant difference was found in pupal duration and adult longevity between treatments.Mating experiments showed that the pre-oviposition duration of F_(1),the larval and pupal durations,adult longevity were not different among four mating groups,but the oviposition duration,the pupal weight and the fecundity were significantly different among treatments.The YF×YM group had the longest reproduction duration(8.07 d)and the highest number of eggs(938.77 eggs per female),while the YF×EM group had the highest pupal weight(354.59 mg).These results suggested that feeding corn leaves and mating with different populations could effectively promote population rejuvenation in M.separata.