胡瓜新小绥螨和尼氏真绥螨生物学特性比较研究

Comparative observations on biology of Neoseiulus cucumeris and Euseius nicholsi (Acari: Phytoseiidae)

胡瓜新小绥螨Neoseiulus cucumeris和尼氏真绥螨Euseius nicholsi是重要的捕食性天敌,其中前者为引进种类,后者为本地种类。本文在室内25℃条件下,以粉螨为食料饲养胡瓜新小绥螨,以二斑叶螨为食料饲养尼氏真绥螨,组建生殖率表,结果表明:胡瓜新小绥螨的产卵量(平均36.35±5.56粒/雌)、內禀增长率(rm=0.0942)、周限增长率(λ=1.0988)均高于尼氏真绥螨的平均产卵量29.78±3.11粒/雌、内禀增长率rm=0.0827、周限增长率λ=1.0863,且种群倍增时间(t=7.35d)也较尼氏真绥螨(t=8.38d)短。通过各参数的比较,在恒温25℃条件下,胡瓜新小绥螨具有较大的生殖潜力。在以桔全爪螨为食料,进行混合饲养时,两种捕食螨的种群增长均受到抑制,而尼氏真绥螨受到的抑制更明显。说明胡瓜新小绥螨竞争力强于尼氏真绥螨。

The possible competition between Neoseiulus cucumeris, an exotic predacious mite, and E. nicholsi, a native species, was studied in laboratory. When N. cucumeris was fed on Acarus sp. and E. nicholsi on Tetranychus urticae at 25 ℃, the cycle rate of increase （ λ）, net productive rate （ R0 ） and population doubling time （t） of N. cucumeris were 1. 0988, 12. 13, and 7.35 days, respectively, while those of E. nicholsi were 1. 0863, 7.94, 9.38 days, respectively. Significant differences were found on the life table parameters between both predacious mites. Average fecundity of them was 36. 35 and 29.78 eggs per female, while longevity were 40. 00 and 35.83 days, respectively, both higher in N. cucumeris than in E. nicholsi. Furthermore, the population doubling time was shorter in N. cucumeris too. The above results showed that N. cucumeris has higher potential productive ability than E. nicholsi. The population growth trends of both predacious mites were significantly decreased when they were reared in mixture, fed on Panonychus citri, but more reduced result found in E. nicholsi. It revealed that N. cucumeris, the exotic species, had stronger competitive ability than E. nicholsi, the native one. Anyhow, both species maintained a stable population if sufficient preys were provided.