Biology of Voria ruralis (Diptera: Tachinidae)1

Oviposition of Voria ruralis (Fallén) on larvae of Trichoplusia ni (Hübner) is described. Average fecundity was 310 eggs per female; the number of eggs varied with size of the female. When Voria oviposited on 1st instars, development was slower and mortality was greater than when oviposition was on other instars, except the late 5th instar. Complete development rarely occurred when eggs were laid on 5th-instars except when they were laid on newly molted individuals. Infection of parasitized 4th-instars with nuclear polyhedrosis resulted in death of host and parasite. The parasite was able to survive when infection was delayed to the beginning of the hosts last stadium. Adult longevity was greater for females than for males.