Archytas marmoratus (Diptera: Tachinidae) Survival in Diapausing and Nondiapausing Strains of Helicoverpa zea (Lepidoptera: Noctuidae)

Archytas marmoratus (Townsend) was reared on four strains of corn earworm, Helicoverpa zea (Boddie). One strain did not diapause or entered a weak diapause. A portion of the other three strains entered diapause when reared at 19 or 22°C and 10:14 h photoperiod (L:D). No A. marmoratus entered diapause; 90% eclosed with no differences among strains or rearing condition, and the number of days from host pupation to eclosion within rearing condition was similar regardless of host strain. Parasitized pupae did not enter a chill-terminated diapause, as indicated by loss of larval eyespots within 2 wks. Either the presence of A. marmoratus maggots prevented diapause in its host or diapause was terminated by rapid development of the maggot after host pupation. These data suggest that A. marmoratus does not overwinter as a larva or pupa in the cooler regions of its distribution.