三氟氯氰菊酯和甲氰菊酯对二点叶螨生命活力及繁殖力的影响

采用室内盆栽和叶盘饲养二点叶螨的方法,测定了三氟氯氰菊酯和甲氰菊酯不同浓度对二点叶螨的生命活力和繁殖力的影响。结果表明:分别用三氟氯氰菊酯10和20mg/L在二点叶螨第Ⅰ若螨期处理后,其成螨寿命、产卵量和卵的孵化率分别比对照增加19.4％和14.0％、41.1％和36.8％以及159.1％和107.3％;当分别用甲氰菊酯7.5和15mg/L在二点叶螨第Ⅰ若螨期处理后,其成螨寿命、产卵量和卵的孵化率分别比对照增加24.7％和23.7％、17.1％和9.21％以及174.2％和141％。用三氟氯氰菊酯20mg/L和甲氰菊酯15mg/L分别处理雌成螨后,其产卵量分别比对照增加24.6％和70.2％。在盆栽菜豆苗上以若螨为主的二点叶螨种群,在用三氟氯氰菊酯10、20mg/L处理后的第7d,其各螨态(成螨、幼若螨和卵)的增长指数分别为3.39和3.68、2.37和4.76、2.58和4.38;用甲氰菊酯7.5、15mg/L处理是3.74和4.82、3.22和4.00、2.30和3.75,均高于同期对照。三氟氯氰菊酯和甲氰菊酯对雌成螨和卵的数量明显增加,对害螨的发生有刺激作用。

Influence of cyhalothrin and fenpropathrin on life-vigor and fecundity of Tetranychus urticae Koch

The effects of cyhalothrin and fenpropathrin under different concentration significantly influenced life vigor and fecundity of Tetranychus urticae Koch, which was determined by pot-culture and leaf-plate method. The results showed that the life period of adult, oviposition number of female and hatchability of egg of T. urticae increased by 19.4% and 14.0%, 41.1% and 36.8%, 159.1 % and 107.3 % compared with that of the CK respectively after the prenymph stage was treated with cyhalothrin 10 mg/L and 20 mg/L. When the adult of female was treated with fenpropathrin 7.5 mg/L and 15 mg/L, the life period of adult, the oviposition quantity per and hatchability of eggs of the mites were 24.7% and 23.7%, 17.1% and9.21%, 174.2% and 141% over that in CK respectively. The oviposition quantity of the adult mites increased by 24.6% and 70.2% after treatment with cyhalothrin (20 mg/L) and fenpropathrin (15 mg/L) compared with that of the CK respectively. A great quantity of T. urticae nymph on kidney bean on pot-culture was treated by cyhalothrin under 10mg/L, 20mg/L respectively, the increment indices of adults, young stage and egg numbers of the mites were 3.39 and 3.68, 2.37 and 4.76, 2.58 and 4.38. It was treated by fenpropathrin 7.5mg/L, 15mg/L respectively ,they were 3.74 and 4.82, 3.22 and 4.00, 2.30 and 3.75, all the these are higher than CK of the same period when the mites were treated after seven days. It is clear that cyhalothrin and fenpropathrin can increase obviously the adult of female and oviposition quantity of Tetranychus urticae Koch; the insecticides had stimulation effects on the development of spidermites.