TEMPERATURE-DEPENDENT DEVELOPMENT OF THE CONVERGENT LADY BEETLE (COLEOPTERA, COCCINELLIDAE)

Development of the covergent lady beetle, Hippodamia convergens Guerin-Meneville, was compared at six constant temperatures. Two populations, one from Corvallis, Oreg., and another from Tuscon, Ariz., did not differ in larval survival or development rates. Morality from eclosion of the first instar to adult emergence was 100, 83, 15, 18, 10, and 5% at 13, 17, 21, 25, 29, and 33-degrees-C, respectively. Development from oviposition to adult ranged from 51.9 d at 17-degrees-C to 11.4 d at 33-degrees-C. The heat-unit-requirements for development from egg to adult were 228 degree-days above a developmental threshold of 12.5-degrees-C. Published data on development on H. convergens from Itahca, N.Y., and Bushland, Tex., suggest a constancy in developmental requirements for the species from four widely separated regions of North America.