溪岸蠼螋的生物学特性及对草地贪夜蛾的捕食能力

Biological characteristics of riparian earwig Labidura riparia and its predatory capacity against fall armyworm Spodoptera frugiperda

为更好保护和利用溪岸蠼螋Labidura riparia,在室内对其形态学特征、发育历期、生活习性以及其对草地贪夜蛾各虫态的捕食能力进行观察和测定。结果显示,在(27.2±0.5)℃、光周期16 L∶8 D、相对湿度(80±5)%条件下用草地贪夜蛾2龄幼虫饲喂时,溪岸蠼螋1个世代的发育历期为73.89 d,其中卵经7.41 d孵化,1~5龄若虫的平均发育历期分别为7.18、6.85、7.20、13.70和13.90 d;雌成虫具有多次交配的能力,寿命为17.68 d,单头产卵次数为4.41次,产卵历期16.86 d,平均单雌产卵量为286.86粒;雄成虫寿命为17.26 d。溪岸蠼螋若虫和成虫对草地贪夜蛾各虫态均有较强的捕食能力,其中溪岸蠼螋雌成虫的日捕食量最大,但与其雄成虫的日捕食量之间差异不显著,但均显著高于溪岸蠼螋1~3龄若虫的日捕食量,与溪岸蠼螋4~5龄若虫日捕食量的差异因草地贪夜蛾虫态不同而不同,溪岸蠼螋雌成虫对草地贪夜蛾1~6龄幼虫和雌、雄成虫的日捕食量分别为31.45、28.80、16.50、8.15、6.40、6.35、5.10和4.95头,溪岸蠼螋雄成虫对草地贪夜蛾1~6龄幼虫和雌、雄成虫的日捕食量分别是29.45、27.40、14.40、8.65、6.10、5.95、4.95和4.85头。表明溪岸蠼螋在防控草地贪夜蛾方面具有较大潜力。

To better protect and utilize riparian earwig Labidura riparia, its morphological characteristics, developmental duration, living habits and predatory ability against fall armyworm Spodoptera frugiperda were observed and measured in the laboratory. The results showed that the average lifespan of L. riparia was 73.89 d for one generation when the nymphs and adults were fed on the 2nd instar larvae of S. frugiperda at(27.2±0.5)℃,(80±5)% relative humidity, and a photoperiod of 16 L∶8 D. The 1st nymphs hatched after 7.41 d. The average developmental durations of the 1st to 5th instar nymphs were7.18, 6.85, 7.20, 13.70 and 13.90 d, respectively. Female adults could mate with male adults for multiple times. The lifespan of female adult was 17.68 d;the female adults laid eggs 4.41 times during their lifetime, and the oviposition period was 16.86 d. The average number of eggs laid per female adult was 286.86. The lifespan of male adult was 17.26 d. The predatory capacity of the nymphs and adults against S. frugiperda were strong. Female adults were the stronger predators, although there was no significant difference in the daily predation capacity between male and female adults. The predation ability of both female and male adults was significantly higher than that of 1st-3rd instar nymphs. The difference in the daily predation of the 4th-5th instar nymphs of earwigs varied with the developmental stages of S. frugiperda. The predation capacities of L. riparia female adults against the 1st-6th instar larvae and female and male adults of S. frugiperda were 31.45, 28.80, 16.50, 8.15, 6.40, 6.35, 5.10 and4.95, respectively;the predation capacities of L. riparia male adults against the 1st-6th instar larvae and female and male adults of S. frugiperda were 29.45, 27.40, 14.40, 8.65, 6.10, 5.95, 4.95 and 4.85, respectively, indicating that L. riparia had the potential for biological control of S. frugiperda.