Effect of \u3ci\u3eBeauveria Bassiana\u3c/i\u3e on Underground Stages Of the Colorado Potato Beetle, \u3ci\u3eLeptinotarsa Decemlineata\u3c/i\u3e (Coleoptera: Chrysomelidae)

Tests were conducted to determine the effect of the fungus Beauveria bassiana (B.b.) on underground of the Colorado potato beetle (CPB), Leptinotarsa decemlineata. Two levels of B.h., g/m2 and 75 g/m2 , were suspended in water and sprinkled over the surface of the ground in cages to which CPB were added, either as overwintering adults or as 4th instar larvae of the 15t generation. Efficacy of treatments was determined by counting emerged adults. Neither level of B .b. increased mortality in overwintering adults. The highest level of B.h. caused a significant decline in emergence of adults from the 1st generation 4th instars. The 7.5 g/m2 treatment level did not significantly differ from control treatments

Effect of Beta·Exotoxin of \u3ci\u3eBacillus Thuringiensis\u3c/i\u3e on Development of the Mexican Bean Beetle (Coleoptera: Coccinellidae)

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