不同性质的杀虫剂对麦田天敌的影响

Effect of Insecticides with Different Characteristic on the Natural Enemies in Wheat Field

评价了不同性质的杀虫剂对麦田天敌的影响。结果表明 ,应用不同性质的杀虫剂可引起捕食性天敌种群数量不同程度的降低。药剂处理后 5～ 10d ,齐螨素、抗蚜威、吡虫啉和氧化乐果处理区捕食性天敌分别减少了 19 6 9% ,4 1 77% ,4 5 75 %和 82 6 9%。抗蚜威和吡虫啉处理区瓢蚜比有较长时间的降低 ,药后 5～ 2 0d其瓢蚜比分别为 1∶31～ 14 9和 1∶34～ 85 ;而氧化乐果处理区瓢蚜比仅短期降低 ,药后 5～ 10d其瓢蚜比为 1∶0～ 2 8,15d后即达到 1∶2 6 5 ;齐螨素处理区瓢蚜比受影响较小。所有参试药剂对蚜茧蜂的寄生率无明显影响。

The effect of insecticides with different characteristic on natural enemies was evaluated in Henan wheat field.The results showed that the application of insecticides could cause different level reductions in the population of predators.Population numbers of predators in plots treated with abamectin,pirimicarb,imidacloprid and omethoate were reduced by as much as 19 69%,41 77%,45 75% and 82 69%,respectively,from 5d to 10d after treatment.Pirimicard and imidacloprid could cause significant relative long term reductions in ratio of ladybird to aphids.The ratio of ladybird to aphids in the plots was 1∶31～149 and 1∶34～85,respectively,from 5d to 20d after treatment in treatment plots.Omethoate could only cause relative short term reductions in the ratio of ladybird to aphids.The ratio of ladybird to aphids from 5d to 10d was 1∶0～28,and the ratio reached 1∶265 in 15d after treatment.The effect of abamectin on ratio of ladybird to aphids was very little.The effect of all used insecticides on parasitism of aphidius was not significant.The IPM was put forward that pirimicarb at 2 5(a.i.)g/667m 2 or 1(a.i.)g/667m 2 could be used as ideal chemicals against wheat aphids in wheat field.