Evaluation of the Efficiency of Bacillus thuringiensis on Larvae and Adults of Andrector ruficornis on Solanum tuberosum plants in Cameroon. The efficiency of Bacillus thuringiensis as an insecticide on the larvae and adults of A. ruficornis (a leaf eating pest) was investigated on Solanum tuberosum plants grown in the field. The results show that, one hour following the treatment of A. ruficornis with a 1.4 g/l suspension of Bacillus thuringiensis, larvae and adults are paralysed on the plants. A high mortality of the insects is observed 48 hours later and the mortality rate reaches 100% after 72 hours. The use of bitoxibacilline (made of Bacillus thuringiensis spores) results in an increase in tuber production (32%) as well as the starch of tubers (from 18 to 27% of fresh weight) and vitamin C (from 9.7 to 11.9 mg/100g fw of tubers). Our observations show that Bacillus thuringiensis powder is an efficient insecticide specific to potato Chrysomelidae.