Susceptibility of Five Plant Defoliators to Celery Looper (Lepidoptera: Noctuidae) Nuclear Polyhedrosis Virus

Bioassays were conducted to determine the susceptibility of five lepidopteran defoliators to a nuclear polyhedrosis virus (NPV) isolated from the celery looper, Anagrapha falcifera (Kirby). Tobacco budworm, Heliothis virescens (F.), exhibited the greatest susceptibility, LC₅₀ = 2,328PIB/ml, and velvetbean caterpillar, Anticarsia gemmatalis (Hübner), exhibited the least susceptibility, LC₅₀ = 5,176,038 PIB/ml, after 7 d of feeding at the 5 × 10⁴ PIB/ml dosage. Corn earworm, Helicoverpa zea (Boddie), soybean looper, Pseudoplusia includens (Walker), and beet armyworm, Spodoptera exigua (Hübner), expressed intermediate levels of susceptibility, LC₅₀ - 11,742, 14,195, 14,614 respectively, after 7 d of feeding at the 5 × 10⁴ PIB/ml dosage. These results were consistent at days 10 and 14 indicating the relative activity of the virus against each species.