敌死虫对不同发育阶段烟粉虱的生物活性测定

敌死虫对烟粉虱成虫具有较强的驱避作用 ,99.1%敌死虫200、100、50倍液药后 2h～120h对黄瓜上烟粉虱的驱避率均在90%以上 ,50倍液处理药后3d的驱避率为98%～100%。药剂处理的非洲菊上烟粉虱成虫产卵量显著低于对照。敌死虫对烟粉虱卵具有一定活性 ,致死中量为10468.6mg/kg ;对若虫活性较高 ,对1、2、3龄若虫的致死中量分别为165.81、199.46、232.38mg/kg ,稀释倍数分别为5976、4968、4264倍。

Bioassays on D-C Tron to Bemisia tabaci of different developmental stages

The biological activities of D-C Tron, a petroleum-based mineral oil, to Bemisia tabaci of different developmental stages were tested. The results showed that the oil was strongly repellent against adult whiteflies. The repellent rate was over 90% after 2h-120 h at 200, 100 and 50 dilutions on cucumber. And the repellent rate was 98%-100% after 3d at 50 dilution. The adults laid less eggs on sprayed Gerbera jamesonii. The ovicidal activity was relatively low, with LD 50 of 10 468 6 mg/kg. The larvicidal activity against the first, second and third instars was high, and the LD 50 were 165 81, 199 46 and 232 38 mg/kg, respectively at 5976, 4968 and 4264 dilutions.