Laboratory toxicity and field efficacy of Lufenuron, Dinotefuran and Thiamethoxam against Hypera postica (Gyllenhal, 1813) (Coleoptera: Curculionidae)

Abstract : Toxicity of the insect growth regulator lufenuron and two neonicotinoids, dinotefuran and thiamethoxam, for the alfalfa weevil, Hypera postica (Gyllenhal, 1813), was determined through exposure of the second instar larvae and adults to dipped alfalfa leaves under laboratory conditions at 25±1 °C, 60±5% RH ,16:8 L:D. Based on mode of action, the mortality of the treated larvae and adults was recorded after 72 hours for lufenuron, and after 24 hours for dinotefuran and thiamethoxam. LC50 values for second instar larvae were 34.32,, 15.82 AI L-1 and for adults were 175.67, 289.76, 164.02 AI L-1 for dinotefuran, thiamethoxam and lufenuran, respectively. Results showed that lufenuron was the most toxic to both larvae and adults of H. postica among insecticides tested. Once the height of alfalfa field reached to about 20 cm, a single treatment was made on May 11th. All insecticides reduced the mean number of alfalfa weevil. According to results of laboratory and field experiments, lufenuron might be a more valuable chemical to adequately control H. postica with little adverse effects on environment. lufenuron may be considered as alternative chemicals to other compounds with a high potential for controlling certain pests and with less adverse effects on natural enemies
Keyword : Alfalfa weevil, Dinotefuran, LC50, Lufenuron, Thiamethoxam
Author(s) : , M. Moradi-Vajargah, H. Rafiee-Dastjerdi, A. Golizadeh, M. Hassanpour, B. Naseri
Downloads : 1371

Download View 2013 Vol. 8 Number 1