An environmentally safe and tolerant microbial insecticide utilizing Helicoverpa armigera single nucleopolyhedrovirus (HearNPV-TR)

Abstract

Background Baculoviruses are significant biocontrol agents of pests in agriculture; however, ultraviolet light B (UV-B) and high temperature inactivate them in the environment within a short time. Results In this study, formulations of Helicoverpa armigera nucleopolyhedrovirus Turkey isolate (HearNPV-TR) were prepared. Crude virus, the oil-based formulations of the virus, and a commercial H. armigera NPV product were exposed to UV-B light and various temperatures (28, 35, and 42 °C) at different periods (0, 1, 3, 5 h.). While the UV-B application decreased the virulence of crude virus up to 32% after 5 h. exposure, it decreased the virulence of oil-based formulation by (15%). Similarly, the virulence of the crude virus by 70% at 42 °C, while was reduced by 10% in the formulations at the same temperature. Therefore, 5% oil formulation was enough to keep the virulence of the virus underexposed to UV-B and high temperatures. LC95 values were calculated as 1 × 108 OBs/ml−1 in concentration–response tests, and mortality rates were 90 and 92% in pot assays for commercial product and 5% oil formulation, respectively. Conclusions The results showed that 5% oil formulation of HearNPV-TR was an important biocontrol preparation to protect virus virulence under suppressive environmental conditions.

Development of novel betabaculovirus (HycuGV-Hc1) as a biopesticide (HycuGV-TR61) and its efficacy on the fall webworm, Hyphantria cunea Drury (Lepidoptera: Erebidae) larvae

“…2). In a study, it was determined that the mortality rate of a baculovirus at three different temperatures for 0, 1, 3 and 5 h decreased as the exposure time increased (Eroglu and Demirbag 2022). There are some studies in the literature that examined the effect of sunlight on the activity of baculoviruses (Sayed et al 2020).…”