Department of Entomology, University of Agriculture Faisalabad, Faisalabad, Pakistan.
Department of Entomology, Abdul Wali Khan University Mardan, Khyber Pakhtunkhwa, Pakistan.
Ecotoxicology. 2021 Apr;30(3):448-458. doi: 10.1007/s10646-021-02372-y. Epub 2021 Mar 5.
Cotesia flavipes Cameron is an important larval parasitoid exploited for the control of the spotted stem borer, Chilo partellus (Swinhoe). Several studies have evaluated the toxic effects of insecticides on C. partellus, however, little is known about non-target effects of insecticides on this parasitoid, when used to control C. partellus. This laboratory study evaluated the lethal and sublethal effects of twelve insecticides on C. flavipes. Residual toxicity tests showed that organophosphates (chlorpyrifos, triazophos and profenofos) exhibited highest contact toxicity to C. flavipes adults with a LC range from 0.63 to 1.05 mg a.i/l, while neonicotinoids (nitenpyram, acetamiprid and imidacloprid) were less toxic to C. flavipes with a LC range from 1.27 to 139.48 mg a.i/l. Sugar-insecticide feeding bioassays showed that organophosphates, pyrethroids (cypermethrin, bifenthrin and lambda-cyhalothrin) and carbamates (thiodicarb, carbaryl and methomyl) were highly toxic to C. flavipes adults and caused 100% mortality at 48 h of exposure, while imidacloprid caused 66% mortality at 48 h of exposure. Risk quotient analysis showed that among all tested insecticides, imidacloprid and acetamiprid were less toxic to C. flavipes adults with a risk quotient value of 0.88 and 1.6, respectively. Furthermore, exposure of immature C. flavipes through their host bodies significantly decreased the parasitism rate at their F and F generations. Risk quotient analysis of insecticides indicated that imidacloprid and acetamiprid were the least toxic to C. flavipes. This study provides important information that will be used in incorporating the most suitable insecticides in integrated pest management programs with reduced negative impacts on non-target beneficial arthropods.
丽蚜小蜂是鳞翅目幼虫的重要寄生蜂，被广泛用于防治水稻二化螟。尽管已有许多研究评估了杀虫剂对二化螟的毒性作用，但关于在防治二化螟时这些杀虫剂对该寄生蜂的非靶标效应却知之甚少。本实验室研究评估了 12 种杀虫剂对丽蚜小蜂的致死和亚致死效应。残效毒性试验表明，有机磷杀虫剂（毒死蜱、三唑磷和丙溴磷）对丽蚜小蜂成虫具有最高的触杀毒力，LC 范围为 0.63-1.05mg a.i./L，而新烟碱类杀虫剂（吡虫啉、噻虫嗪和氯噻啉）对丽蚜小蜂的毒性较低，LC 范围为 1.27-139.48mg a.i./L。糖-杀虫剂饲喂生物测定表明，有机磷杀虫剂、拟除虫菊酯（氯氰菊酯、溴氰菊酯和高效氯氟氰菊酯）和氨基甲酸酯类（硫丹、灭多威和涕灭威）对丽蚜小蜂成虫具有高毒性，暴露 48 小时后死亡率为 100%，而氯噻啉在暴露 48 小时后引起 66%的死亡率。风险商数分析表明，在所测试的杀虫剂中，氯噻啉和噻虫嗪对丽蚜小蜂成虫的毒性较低，风险商数值分别为 0.88 和 1.6。此外，通过其宿主虫体暴露于不成熟的丽蚜小蜂会显著降低其 F1 和 F2 代的寄生率。杀虫剂的风险商数分析表明，氯噻啉和噻虫嗪对丽蚜小蜂的毒性最低。本研究提供了重要信息，将有助于在减少对非靶标有益节肢动物负面影响的前提下，将最适合的杀虫剂纳入病虫害综合防治计划中。
