Insecticidal Activity of Two Biological Pesticides against Ostrinia furnacalis
DONG Yi-zhia, LU Henga, CHEN Bing-xua, ZHENG Jin-rongb(Guangdong Academy of Agricultural Sciences a.Plant Protection Research Institute; b.Crops Research Institute, Guangzhou 510640, China)
The toxicity of 2 biological pesticides abamectin and B.t. to 3rd instar larvae of Ostrinia furnacalis were determined by using potter spray tower. The result showed that the LC50 value of abamectin were 8.23, 4.83 and 4.05 mg/L in 24, 48, 72 h after treatment respectively and the LC50 value of B.t. were 4.62×106, 2.23×106, 1.86×106 IU/L, respectively. The result of field trial indicated that abamectin and B.t. had high control efficacy against O. furnacalis. The control efficiency of abamectin 1.8% EC at dose 16.2 g a.i./ha, 8000 IU/mg B.t. WP and 2000 IU/mg B.t. GR at dose of 1.44×1010 IU a.i./ha were 83.24, 86.60, 84.32%, respectively.