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Recently,occurrence of grub in peanut field is showing a increasing tendency.Grub is ruinous pest on peanut,with a wide range of species and different life habit and complicated regularity of outbreak,which makes their preventing and controlling difficult.For finding out efficient controlling strategy and screening out effective pesticide,investigation of grub species and their regularity of outbreak were conducted in Changsha,Shaoyang,and Yongzhou in hunan province,as well as bioassay and field trial of five pesticides against grub. Results included:1、Dominant species in the three districts all were Anomala corpulenta,Holotrichia parallela,Holotrichia oblita,and their proportion were:52.35%,30.53%,11.91%.2、Anomala corpulenta had high tropism on sweet potato,peanut and citrus.Holotrichia parallela had high tropism on soy.In Yongzhou,Holotrichia parallela had high tropism on ramie and polygonum perfoliatum,and Holotrichia oblita had high tropism on peanut and citrus.3、initial position and apex of occurrence in peanut field in the above-mentioned district all fallowed the time sequence:Anomala corpulenta,Holotrichia parallela,Holotrichia oblita. In Yongzhou,peak of egg laying occurred on middle third of June,and on last third of July in Changsha,last third of June in Shaoyang.In Yongzhou,Shaoyang and Changsha,occurrence peak occurred respectively on first third of June,first third of July and first third of August.4、By test of crowding level,Taylor,Iwao M*-X,results showed that:grub in the three districts all presented gathering distribution,and formulas of their spot check in field trial, were confirmed,N=[83.87233/X+8.38606]/D2（Changsha）, N=[116.72871/X+7.95145]/D2（Shaoyang）,N=[(185.23527/X+7.83174]/D2（Yongzhou）,D is permitting error,X is average density of grub,N is theoretical number of sample.5、Results of bioassay of five pesticides to Anomala corpulenta showed that: Deltamethrin had lowest virulence,with 24 hours treatment LC50 of 25.3509mg/L and 48 hours treatment LC50 of 21.3362mg/L.Carbosulfan had highest virulence,with 24 hours treatment LC50 of 16.1902mg/L and 48 hours treatment LC50 of 10.2784mg/L.Phoxim and Dursban had similar virulence,with 24 hours treatment LC50 closeing to 17 mg/L and 48 hours treatment LC50 closing to 13mg/L.6、Results of field trial in peanut filed against grub showed that:30%Dursban SC by 500g/667m2,15%Dursban GR by 2000g/667m2,35%Carbosulfan FS by 150g/667m2 had best pesticide effect and lasting effect.
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