Abstract:
Objective In this paper, we used 3-bromopyruvate (3-BrPA) as a biological synergist of Hyphantria cunea nucleopolyhedrovirus (HycuNPV) to investigate the effect of 3-BrPA on the virulence of HycuNPV and the growth and development of Hyphantria cunea, which will provide new synergist resources for the application of HycuNPV insecticides.
Method The synergistic effect on HycuNPV was analyzed by adding different doses of 3-BrPA incorporating with HycuNPV in laboratory.
Result The bioassay results showed that 3-BrPA had a synergistic effect on HycuNPV. It could not only improve infectivity of HycuNPV, but also increase the insecticidal speed. When the dosages of 3-BrPA with 5.0, 10.0 and 15.0 mg·g−1 were added to HycuNPV, the LC50 of HycuNPV in the 3rd instar larvae of H.cunea decreased. The synergistic ratio (SR) of HycuNPV were 825.14, 164.72 and 0.47, and the co-toxicity coefficients (CTC) were 82613.63, 16579.25 and 147.27, respectively. Different concentrations of HycuNPV had different insecticidal effects under the different doses of 3-BrPA. Added different doses of 3-BrPA, the LT50 of HycuNPV against the larvae were shorten by 3.280~9.724 d. According to SR, CTC, LT50 and ST, the optimum synergistic effect was observed: 5.0 mg·g−1 3-BrPA + 9.0 × 105 OBs·mL−1 HycuNPV. In addition, the combination of 3-BrPA and HycuNPV significantly inhibited the growth and development of larvae, and the pupation and emergence rate of surviving larvae were significantly lower than that of the virus insecticide alone.
Conclusion 3-BrPA has a synergistic effect on HycuNPV, and is expected to be an ideal synergistic resource of viral insecticides.