Development of Overwintering and Summer Generation Pupae of the Alfalfa Blotch Leaf miner, Agromyza frontella (Diptera: Agromyzidae), in Central New York1

Abstract

Developmental periods and rates at constant temperatures were determined for field-collected overwintering generation pupae and summer generation pupae from field-collected larvae of the alfalfa blotch leaf miner, Agromyza frontella (Rondani). Overwintering and summer generation pupae, respectively, had median developmental periods of 62 and 142 days at 10°C, 29 and 38 days at 15°C, 17 and 23 days at 20°C, and 13 and 17 days at 25°C. At most temperatures, the median period for overwintering pupae was 20% less than that for summer pupae. Developmental rates for overwintering pupae gave reasonable simulations of spring adult emergence patterns as did rates for summer pupae with respect to summer generation emergence patterns at two sites in central New York during 1977 and 1978. However, the rates for summer pupae did not give adequate simulations of spring emergence, indicating that the developmental rate differences between overwintering and summer generation pupae had phenological significance under field conditions.