Bacillus thuringiensis Strain Buibui for Control of Cupreous Chafer, Anomala cuprea (Coleoptera: Scarabaeidae), in Turfgrass and Sweet Potato

The efficacy of the toxin from Bacillus thuringiensis serovar japonensis (strain Buibui), which is specific to scarabaeid larvae, was evaluated in turfgrass pots. The toxin controlled first and second instars of the cupreous chafer, Anomala cuprea, at 2 mg protein/pot and the greenness of the turfgrass did not deteriorate. On the other hand, the efficacy against the third instar was less than that against the first and second instars, and the greenness and dry weight of the turfgrass were reduced. However, the mortality against the third instar was 48% compared with 8% for the control. In the field, the effectiveness of the Buibui toxin was evaluated in sweet potato plots. The ratio of damaged potatoes in the treated plots with the Buibui toxin was 31% compared with 69% for the control plots. The index of damage to sweet potato in the treated and untreated plots was 23 and 55, respectively. These results suggest that the toxin at 100 mg/m² effectively controlled the cupreous chafer in the sweet potato fields.