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

Abstract

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 (Hübner, 1805) (Lepidoptera: Noctuidae) and Spodoptera exigua (Hübner, 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 4.7x105 occlusion bodies (OBs)/ml in H. cunea , 5.6x106 OBs/ml in L. dispar, 7x107 OBs/ml in S. exigua , 1.5x109 OBs/ml in M. neustria and 7.7x109 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 .