八种杀虫剂对愈纹萤叶甲成虫的毒力及田间防控效果

【目的】为探索适用于愈纹萤叶甲Galeruca reichardti成虫的防治药剂室内毒力测定方法,并筛选其防治的有效药剂。【方法】分别采用浸虫法、浸叶法和胃毒触杀联合毒力法测定了8种药剂对其成虫的毒力,并通过大田试验进一步验证。【结果】浸虫法测得除虫菊素对愈纹萤叶甲成虫的毒力最高,其LC50值为68.24 mg/L;浸叶法测得氟啶虫胺腈的毒力最高,其LC50值为111.11 mg/L;胃毒触杀联合法测得氟啶虫胺腈的毒力最高,其LC50值为67.94 mg/L。其中,除虫菊素毒力值变化最大,浸虫法毒力是浸叶法的28.97倍,胃毒联合法毒力是浸叶法的17.83倍。蛇床子素、苦参碱在3种生测方法中毒力较低。田间试验结果显示,50%氟啶虫胺腈水分散粒剂562.5 g/hm2防治效果达94.90%,对韭菜苗保苗效果为81.45%,且显著高于其他药剂。【结论】3种毒力测定方法均可用于该虫的毒力测定,而从此虫的为害特点来看,胃毒触杀联合毒力法更能显示药剂的毒力性质。在愈纹萤叶甲成虫盛发期选择氟啶虫胺腈喷施可以有效减轻该虫为害。

Relative effectiveness of eight insecticides in controlling adult Galeruca reichardti

Objectives]To explore appropriate pesticide bioassay methods and select effective insecticides for the control of adultGaleruca reichardti. Methods] The toxicities of eight pesticides to G. reichardti were determined by the insect-dipping and leaf-dipping tests, and by the contact and ingestion methods. The effectiveness of control was assessed by a field experiment.Results] The relative toxicity of the pesticides varied according to the test used. Pyrethrin was the most toxic with respect to the insect-dipping test, however, on the basis of the leaf-dipping, contact and ingestion methods, sulfoxaflor was the most toxic with LC50 values of 68.24, 111.11 and 67.94 mg/L, respectively. The toxicity of pyrethrin with respect to the insect-dipping, contact and ingestion methods was respectively 28.97 and 17.83 times that in the leaf-dipping test. Cnidium monnieri and matrine had the lowest toxicities in every bioassay. The results of the field experiment showed that application of 50% sulfoxaflor water dispersible granules at a density of 562.5 g/hm2reduced pest abundance by 94.90 %, and reduced damage to Chinese chive seedlings by 81.45%; significantly better than the results achieved with the other pesticides. Conclusion] Although all three bioassay methods can be used to determine the toxicity of insecticides, the contact and ingestion methods should become the standard bioassays. Of the pesticides tested, sulfoxaflor was the best for controllingG. reichardtiin Chinese chive crops.