Safety of Chromolaena odorata (Asteraceae) leaf extracts against Trichogramma japonicum Ashmead

Solvent extracts of leaves of Chromolaena odorata, a widely distributed neo-tropical shrub having insecticidal properties, was tested for its safety to Trichogramma japonicum, a popular egg parasitoid of lepidopteran pests of rice, which revealed that extract toxicity could be arranged as petroleum ether < water < methanol < acetone < chloroform in terms of safety to adults causing 28.3% < 40.0% < 43.3% < 53.3% < 65.0% adult mortality at 1.0% concentration after 24 hours of treatment. Respectively, the LC₅₀ values of solvent extracts were 7.98%, 5.20%, 3.65%, 1.62% and 0.02%. Petroleum ether, water and methanol extracts of C. odorata at 1% concentration were ranked as harmless, however, remaining extracts were moderately harmful to the egg parasitoid even after 24 hrs of treatment.