Bioactivity of a betabaculovirus, Hyphantria cunea granulovirus, in six lepidopteran insects as potential hosts

The aim of this study, conducted in 2018 and 2020, was to investigate the bioactivity of a local baculovirus isolate, Hyphantria cunea granulovirus (HycuGV), in seven lepidopteran pests. Based on data collected 10 days after exposure, HycuGV was found to infect Malacosoma neustria (L., 1758) (Lepidoptera: Lasiocampidae), Lymantria dispar (L., 1758) (Lepidoptera: Erebidae), Helicoverpa armigera (Hubner, 1805) (Lepidoptera: Noctuidae) and Spodoptera exigua (Hubner, 1808) (Lepidoptera: Noctuidae) larvae as well as its host Hyphantria cunea (Drury, 1773) (Lepidoptera: Erebidae). However, it did not infect Spodoptera littoralis (Boisduval, 1883) (Lepidoptera: Noctuidae) and Cydia pomonella (L., 1758) (Lepidoptera: Tortricidae). A HycuGV dose rate experiment indicated LC50 of 4.7x10(5) occlusion bodies (OBs)/ml in H. cunea, 5.6x10(6) OBs/ml in L. dispar, 7x10(7) OBs/ml in S. exigua, 1.5x10(9) OBs/ml in M. neustria and 7.7x10(9) OBs/ml in H. armigera. HycuGV was infectious to S. exigua and L. dispar, but only provided effective control in M. neustria and H. armigera at high dose rates. These findings demonstrate that HycuGV can be highly effective for control of S. exigua, L. dispar and H. cunea.