甲氰菊酯和阿维菌素对柑橘全爪螨的亚致死效应

通过叶碟饲养的方法, 利用生命表技术,研究了甲氰菊酯和阿维菌素亚致死剂量LC₂₀处理柑橘全爪螨若螨后,对试验种群当代(F₀)和后代(F₁、F₂代)生长发育及繁殖的影响.结果表明: 甲氰菊酯LC₂₀处理若螨后,当代雌成螨产卵量显著增加;F₁、F₂代的产卵前期缩短,后代雌性比例增大,且均与对照差异显著;同时,F₁和F₂代种群内禀增长率(r_m)和周限增长率(λ)增大,世代历期(T)和种群加倍时间(Dt)缩短,且F₂代与对照相比差异显著.用阿维菌素LC₂₀处理若螨后,当代种群雌成螨产卵量显著下降; F₁和F₂代的产卵量也显著下降,但后代雌性比例增大,产卵前期显著缩短;F₁和F₂代的种群r_m和λ增大,T和Dt缩短,且F₂代比F₁代更为明显.总体来看,甲氰菊酯和阿维菌素亚致死浓度LC₂₀对柑橘全爪螨的影响并不完全相同,甲氰菊酯能够促进当代种群的发展,而阿维菌素对当代种群有一定的抑制作用;但两种杀螨剂亚致死浓度处理柑橘全爪螨对后代种群都有一定的促进作用.研究结果对柑橘全爪螨综合防治策略的制定有一定的指导意义.

Sublethal effects of fenpropathrin and avermectin on Panonychus citri (Acari: Tereanychidae).

A leaf disc bioassay was employed to examine the effects of fenpropathrin and avermectin with a sublethal concentration of LC₂₀ on the development and reproduction of F₀, F₁ and F₂ generations by means of life tables. The results showed that after the treatment of fenpropathrin at the sublethal concentration, the number of eggs laid per female significantly increased in F₀ generation, the pre-oviposition duration was significantly shortened and the female ratio of offspring significantly increased both in F₁ and F₂ generations. The intrinsic rate of increase (r_m) and finite rate of increase (λ) values all increased, and the generation time (T) and population doubling time (Dt) were shortened in F₁ and F₂ generations, with significant difference observed between F₂ generations and the control. After exposure to avermectin, the number of eggs laid per female significantly decreased in F₀ generation, and progeny (F₁ and F₂) also produced fewer eggs than the control, while the female ratio of offspring increased both in F₁ and F₂ generations and the pre-oviposition period was significantly shortened. The r_m and λ values all increased, and the T and Dt were shortened in F₁ and F₂ generations. Such effects were more obvious on the F₂ generation than the F₁ generation. Generally, the effects of fenpropathrin and avermectin with a sublethal concentration of LC₂₀ were not exactly the same on P. citri. Fenpropathrin could promote the development of the contemporary population, while avermectin had certain inhibition on the contemporary population, but both played a certain role in facilitating the development of future populations, which was of significance in developing integrated pest management strategies.