Biological Characteristics of a South American Population of Voria ruralis (Diptera: Tachinidae), a Larval Parasitoid of the Soybean Looper (Lepidoptera: Noctuidae) 1

Abstract

Voria ruralis (Fallen) was collected in Uruguay and Argentina and imported into the United States, where studies were conducted to determine its developmental time, longevity, and other characteristics of its biology when reared on the soybean looper, Pseudoplusia includens (Walker). Parasitoid developmental time from egg to pupation ranged from 7 to 9 days, and from pupation to adult emergence ranged from 7 to 8 days at 27 ± 2°C. Males reached the adult stage faster than females (15.43 and 16.12 days, respectively). Gregarious parasitism occurred frequently under our laboratory rearing conditions, and each parasitized host yielded an average of 2.15 puparia. Longevity of unmated adult males (ca. 20 days) was less than that of unmated or mated females (ca. 24 and 28 days, respectively). On the average, mated females lived 3 to 4 days longer than unmated females. More hosts were parasitized by V. ruralis in the morning (9 to 12 a.m.) than in the afternoon (1 to 4 p.m.).