A viral biopesticide from native Hyphantria cunea granulovirus (HycuGV) to control fall webworm (Hyphantria cunea, Drury, Lepidoptera: Arctiidae) under field conditions.

This study evaluated the efficacy and shelf life of a locally developed viral prototype product based on Hyphantria cunea granulovirus (HycuGV-Hc1) for the control of the fall webworm (Hyphantria cunea Drury; Lepidoptera: Arctiidae), a polyphagous pest commonly observed in the Black Sea and Marmara regions of Turkey, under field conditions. The field trials were conducted in Trabzon, in the Eastern Black Sea Province, during 2022 and 2023. The viral formulation was tested on mulberry, hazelnut, and walnut host plants against Hyphantria cunea larvae at 2 × 108, 2 × 107, and 2 × 106 occlusion body (OB)/ml concentrations. AGREE 50 WG (Commercial Product), which contains 50% Bacillus thuringiensis as the active ingredient used in Turkey against H. cunea was used as a comparison. At the highest concentration, the mortality rates were recorded at 85.42%, 80.85%, and 79.59% for mulberry, hazelnut, and walnut plants, respectively. When comparing the control groups across different plants, the most damage was observed on the mulberry plant. Comparable efficacy was observed with the commercial B. thuringiensis pesticide. In the shelf-life study, formulations prepared for different periods (0, 6, and 12 mo) were found to have similar mortality effects. The local viral prototype product displayed significant potential for controlling Hyphantria cunea in the field condition at 7 d after application.