Fall development and potential diapause in pupae of the alfalfa blotch leafminer, Agromyza frontella (Diptera: Agromyzidae).
Temperature-dependent simulation models for nondiapause and postdiapause development of pupae of Agromyza frontella (Rond.), a pest of lucerne in Maryland, were used to analyse the late summer and autumn development of pupae under field and laboratory conditions. Pupal development during the second summer generation was accurately simulated by the non-diapause model under both laboratory and field temperature conditions. Adult emergence in the field during the autumn generation was overestimated by the non-diapause model used in conjunction with recorded field soil temperatures. This suggested that diapause occurred in the autumn generation, although prolonged pupal development was not readily observed in the laboratory. The development of autumn generation pupae collected from the field in October and November and reared under controlled temperatures was adequately simulated by the postdiapause model but not the non-diapause model. The results suggest that an autumn generation pupal diapause occurs and is largely completed by November.