Mexican bean beetle larvae were fed several levels of Bacillus thuringiensis var. thuringiensis that contained the beta-exotoxin to determine if this treatment would extend or prolong their preadult life span. Feeding on bean foliage sprayed with a solution containing 2 g/liter active ingredient diluted I: 10,000, extended the life by 7.5 days. Dilutions of I: 15,000 and 1:20,000 extended the life by over 3 and 5 days, respectively. By extending the time of larval development, enhancement of parasite or predator activity may occur.
Cantwell, George E.; Cantelo, William W.; and Cantwell, Michael A.
"Effect of Beta·Exotoxin of Bacillus Thuringiensis on Development of the Mexican Bean Beetle (Coleoptera: Coccinellidae),"
The Great Lakes Entomologist, vol 19
Available at: https://scholar.valpo.edu/tgle/vol19/iss2/5