GENETICALLY MODIFIED CROPS AND GROUND BEETLES AS NON-TARGET ORGANISMS: DEVELOPING DIETARY TOXICITY ASSAYS FOR LARVAE OF POECILUS CHALCITES (COLEOPTERA: CARABIDAE)

Authors: DUAN, JIAN - MONSANTO COMPANY; PARADISE, MARK - MONSANTO COMPANY; Lundgren, Jonathan; WIEDENMANN, ROBERT - UNIVERSITY OF ARKANSAS

Submitted to: American Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/3/2005
Publication Date: 11/1/2005
Citation: Duan, J.J., Paradise, M.S., Lundgren, J.G., Wiedenmann, R.N. 2005. Genetically modified crops and ground beetles as non-target organisms: developing dietary toxicity assays for larvae of Poecilus chalcites (Coleoptera: Carabidae). American Entomologist, 51(4):227-230.

Interpretive Summary: We developed a procedure for administering dietary toxins to larvae of Poecilus chalcites, an abundant ground beetle occurring in agricultural systems. A rearing protocol relying on an artificial diet described here was a critical development allowing us to conducted diet-incorporated toxicity assays. The system was validated using the cysteine-protease inhibitor E-64, which is similar to cysteine-protease inhibitors expressed in insect-resistant transgenic crops. Doses of E-64 were 0, 60, 150, and 600 ug/g of diet. Larvae were reared on the different diets throughout larval development, and the larval duration, survival, and developmental rates were recorded for each treatment. 600 ug of E-64 per gram of diet was shown to reduce the developmental rate of P. chalcites larvae. Thus, we have developed an assay procedure that can henceforth be used to evaluate the toxicity of different insecticidal substances, including newly emerging gene products from transgenic crops.

Technical Abstract: We developed a procedure for administering dietary toxins to larvae of Poecilus chalcites, an abundant ground beetle occurring in agricultural systems. A rearing protocol relying on an artificial diet described here was a critical development allowing us to conducted diet-incorporated toxicity assays. The system was validated using the cysteine-protease inhibitor E-64, which is similar to cysteine-protease inhibitors expressed in insect-resistant transgenic crops. Doses of E-64 were 0, 60, 150, and 600 ug/g of diet. Larvae were reared on the different diets throughout larval development, and the larval duration, survival, and developmental rates were recorded for each treatment. 600 ug of E-64 per gram of diet was shown to reduce the developmental rate of P. chalcites larvae. Thus, we have developed an assay procedure that can henceforth be used to evaluate the toxicity of different insecticidal substances, including newly emerging gene products from transgenic crops.