苦参碱及吡虫啉对南方小花蝽的影响

Effects of matrine and imidacloprid on Orius similis

为评价植物源杀虫剂和化学杀虫剂对南方小花蝽的影响,在室内条件下采用浸渍法比较了苦参碱及吡虫啉对西花蓟马的毒力,并分别利用两种杀虫剂对西花蓟马2龄若虫的LC50剂量作用于南方小花蝽,探究其对南方小花蝽捕食作用、雌成虫寿命和产卵量的影响。结果显示,苦参碱和吡虫啉对西花蓟马2龄若虫的LC50值分别为24.811 mg/L和13.911 mg/L,两种药剂处理后南方小花蝽对西花蓟马的功能反应符合HollingⅡ圆盘方程,但其瞬时攻击率降低,苦参碱处理的瞬时攻击率高于吡虫啉处理;药剂处理后南方小花蝽雌成虫寿命及产卵量均下降,雌成虫寿命由22.0 d分别缩至19.0 d及11.0 d,其平均日产卵量由3.92粒/雌分别下降至2.25粒/雌及0.91粒/雌。研究表明苦参碱对南方小花蝽的影响小于吡虫啉。

To evaluate the effect of botanical insecticides and chemical insecticides on Orius similis, the toxicities of matrine and imidacloprid on Franklinidla occidentalis were studied in laboratory with dipping method, and the effects of dose of LCs0 of 2 kinds of insecticides to 2nd instar larva of F. occidentalis on female longevity, fecundity and prey consumption of O. similis were assessed too. The results showed that the LCs0 of matrine and imidacloprid to 2nd instar larva of F. occidentalis were 24.811 mg/L and 13.911 mg/L respectively. The functional responses of female adult of O. similis to F. occidentalis were fitted by Holling Ⅱ ＇ s equation after they were treated with 2 kinds of insecticides, but the instantaneous attack rate decreased after O. simili treated with 2 kinds of insecticides, the eggs laid decreased to 2.25 eggs per female per day and 0.91 eggs per female per day respectively compared to 3.92 eggs per female per day of untreated. The female longevities were 19.0 d and 11.0 d respectively. The results indicated that ma- trine was safer for O. similis than imidacloprid.