植物源杀虫剂对椰心叶甲和椰甲截脉姬小蜂的安全性评价

Safety evaluation of botanical pesticides on Brontispa longissima Gestro and Asecodes hispinarum Boucek

采用叶片浸渍法和药膜法测定了4种植物源杀虫剂对椰心叶甲和椰甲截脉姬小蜂的毒力,比较了药剂在二者之间的毒力选择性。结果表明,供试杀虫剂中以印楝素和苦参碱对椰心叶甲和椰甲截脉姬小蜂的选择性最高,其选择性比值(LC50椰甲截脉姬小蜂/LC50椰心叶甲)为0.4856和0.4597;烟碱虽然对椰心叶甲的毒力较高,LC50为9.3095 mg/L,但同时对椰甲截脉姬小蜂的毒力也较高,LC50为1.9286 mg/L,导致对椰甲截脉姬小蜂的安全性较低,选择性比值分别为0.2072。在急需化学药剂迅速降低虫口基数时,可选用烟碱等对椰心叶甲毒力较高的药剂,但当与椰甲截脉姬小蜂混合使用时,则用选用安全性较高的印楝素和苦参碱等植物源杀虫剂。

The selective toxicity of botanical pesticide on Brontispa longissima Gestro and Asecodes hispinarum Boucek was investigated using leaf disc dipping and pesticides membrane methods.Azadirachtin and matrine were most safe to A.hispinarum,and the selective toxicity ratio between B.longissima and A.hispinarum(LC50 B.longissima / LC50 A.hispinarum) were 0.4856 and 0.4597,respectively.Nicotinamide showed best activity to B.longissima,while the toxicity were highest among the botanical pesticides used,and the LC50 to B.longissima and A.hispinarum were 9.3095 and 1.9286 mg/L,respectively,and the selective toxicity ratio were 0.2072,showed the lowest safety to A.hispinarum.Conclusion: Nicotinamide may be used in B.longissima control when pesticides management were used to reduce the pest population,while the botanical pesticides that have high safety to A.hispinarum should be used when pesticides were combine used with A.hispinarum to control B.longissima.