Antifeedant and Growth Inhibitory Effects of Eucalyptus camaldulensis and Callistemon lanceolatus against Helicoverpa armigera (Hübner)

Studies were conducted to assess the biological activity of Eucalyptus camaldulensis and Callistemon lanceolatus against American bollworm, Helicoverpa armigera under laboratory conditions (27±1°C, RH 60±5% and 16:8 h scoto/photo-phase regime) using ‘artificial diet surface incorporation’ technique. Eucalyptus camaldulensis and Callistemon lanceolatus extracts possess insecticidal and juvenomimetic properties against H. armigera, as larval weight, total growth and development was reduced, resulting in deformed individuals which will ultimately affect the future generation of the test insect. Eucalyptus camaldulensis proved more potential than Callistemon lanceolatus in terms of antifeedancy (Al₅₀ 0.059%, 0.085%) and growth inhibition (Gl₅₀ 0.072%, 0.111%), respectively.