Enhanced activity of Agrotis segetum (Schiff.) (Lepidoptera: Noctuidae) granulovirus by boric acid additive [electronic resource].

Includes reference.

The enhancement of Agrotis segetum granulovirus (AgseGV) activity using the boric acid additive was investigated. The bioassay results revealed that the virus suspension contained 0.5, 1,3 and 5% boric acid increased the mortality rate of A. ipsilon 2 nd (5- day old) larvae as compared with the virus alone. This rate of mortality increased with increasing concentration of boric acid added to the virus. The LC₅₀ value of the 2 nd - instar larvae was reduced 10 fold by 3% boric acid + GV. Furthermore, the time required for AgseGV to kill larvae was significantly reduced by boric acid. The boric acid alone did not cause larval mortality at the concentration 0.5 or 1%. The light microscope examination showed that the peritrophic membrane (PM) of A.ipsilon exposed to boric acid alone, or the combined treatment, was markedly disrupted. Obvious ruptures on the outer surfaces of the PM were observed, which potentially facilitated the passage of virions through the PM. Under the semi- field conditions, the reduction of cutworm damage to cotton plants was 62.96% in case of virus alone and reached up to 96% in the boric acid + AgseGV treatment. In conclusion, the combination of boric acid with the baculovirus (AgseGV) may improve the activity of virus formulation.

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