噻虫胺及其混配制剂对意大利蜜蜂和玉米螟赤眼蜂的急性毒性

【目的】明确新烟碱类杀虫剂噻虫胺及其2种混剂对意大利蜜蜂 Apis mellifera ligustica 和玉米螟赤眼蜂 Trichogramma ostriniae 的毒性。【方法】采用摄入法、接触法和药膜法分别测定3种制剂对意大利蜜蜂成年工蜂和玉米螟赤眼蜂成蜂的急性毒性。【结果】急性毒性测定结果表明，30%噻虫胺悬浮剂、30%吡蚜酮·噻虫胺悬浮剂和20%醚菊酯·噻虫胺悬浮剂对意大利蜜蜂成年工蜂的急性摄入毒性均为剧毒，LC₅₀ 值(48 h)分别为0.0200（0.0143~0.0272）, 0.084（0.0658~0.1157）和0.1594（0.1200~0.2056） mg a.i./L；3种制剂对意大利蜜蜂成年工蜂急性接触毒性均为高毒，LD₅₀ 值(48 h)分别为0.0155（0.0114~0.0197）, 0.0426（0.0335~0.0539）和0.1122（0.0796~0.1385）μg a.i./蜂。药膜法测定3种制剂对玉米螟赤眼蜂成蜂的LD₅₀ 值(24 h)分别为0.0232（0.0180~0.0295）, 0.1050（0.0940~0.1170）和0.0059（0.0054~0.0065） mg a.i./L；安全性评价结果表明，3种制剂对玉米螟赤眼蜂成蜂均存在极高风险性，安全系数分别为5.95×10^-4, 2.69×10^-3和9.50×10^-5。【结论】噻虫胺及其混剂对意大利蜜蜂和玉米螟赤眼蜂均存在较高的毒性风险，在害虫综合治理中应谨慎使用。

Acute toxicity of clothianidin and its mixtures to Apis mellifera ligustica (Hymenoptera: Apidae) and Trichogramma ostriniae (Hymenoptera:Trichogrammatidae)

【Aim】 This study aims to clarify the side effects of clothianidin and its two mixtures to Apis mellifera ligustica and Trichogramma ostriniae. 【Methods】 The acute toxicity of clothianidin and its two mixtures to adult workers of A. mellifera ligustica and adult T. ostriniae was determined in the laboratory, and the safety of these insecticides was evaluated. 【Results】 Stomach toxicity tests performed in standardized conditions on adult bees showed that clothianidin insecticides had very high toxicity to the adult workers of A. mellifera ligustica, with the LC₅₀ values of 0.0200 (0.0143-0.0272) for 30% clothianidin SC, 0.0847 (0.0658-0.1157) for 30% pymetrozine·clothianidin SC and 0.1594 (0.1200-0.2056) mg a.i./L for 20% ethofenprox·clothianidin SC, respectively. The LC₅₀ values of 30% clothianidin SC, 30% pymetrozine·clothianidin SC and 20% ethofenprox·clothianidin SC against adult workers of A. mellifera ligustica at 48 h after topical application were 0.0155 (0.0114-0.0197), 0.0426 (0.0335-0.0539) and 0.1122 (0.0796-0.1385) μg a.i. per bee, respectively. All the tested insecticides showed high contact toxicity to adult workers of A. mellifera ligustica. Toxicity of test insecticides to adult T. ostriniae determined by using dry film residue method under laboratory conditions showed that the LC₅₀ values (24 h) of 30% clothianidin SC, 30% pymetrozine·clothianidin SC and 20% ethofenprox·clothianidin SC against adult T. ostriniae were 0.0232 (0.0180-0.0295), 0.1050 (0.0940-0.1170) and 0.0059 (0.0054-0.0065) mg a.i./L, respectively. The results of safety evaluation showed that 30% clothianidin SC, 30% pymetrozine·clothianidin SC and 20% ethofenprox·clothianidin SC were ranked as very high risk to adult T. ostriniaewith the safety factors of 5.95×10^-4, 2.69×10^-3 and 9.50×10^-5, respectively. 【Conclusion】 Clothianidin and its two mixtures have high risk of acute toxicity to both A. mellifera ligustica and T. ostriniae, so the use of these insecticides should be evaluated carefully in integrated pest management (IPM) programs.