Comparative Insecticidal Activity of a Commercial and a Nanoformulation of Pyridalyl against Bollworm, Helicoverpa armigera (Hübner)

Pyridalyl gives good control of various lepidopterous and thysanopterous pests of cotton and vegetables, without causing phytotoxicity. In the present study, bioactivity of a commercial and a nanoformulation of this molecule is reported as contact and stomach poison against Helicoverpa armigera (Hübner). Topical application method was used to evaluate activity as a contact poison, while leaf dip method was used for evaluation of stomach and contact activity. The activity was compared on the basis of their LC₅₀ values. By topical application, LC₅₀ of nano and commercial products of pyridalyl was 90 and 210 μg ml⁻¹ respectively while by leaf dip method it was 40 and 250 μg ml⁻¹. Superior bioefficacy of nanoformulation (0.8%) was further confirmed in a pot experiment on okra.