www.IndianJournals.com Members Copy, Not for Commercial Sale Downloaded From IP - 14.139.222.129 on dated 17-Apr-2019 Surajit Kalita and Lakshmi Kanta Hazarika 276 Research Article Ann. Pl. Protec. Sci. 26 (2) : 276-280 (September, 2018) doi: 10.5958/0974-0163.2018.00062.9 Safety of Chromolaena odorata (Asteraceae) leaf extracts against Trichogramma japonicum Ashmead Surajit Kalita and Lakshmi Kanta Hazarika Department of Entomology, Assam Agricultural University, Jorhat - 785 013 (Assam), India <surjit_kalita@yahoo.com; lkhazarika@yahoo.com> Date of Receipt: 08.06.2018; Accepted: 10.07.2018 ABSTRACT 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 LC 50 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. Key words: Chromolaena odorata, LC 50 value, Trichogramma japonicum, Solvent extract. Indiscriminate use of chemical pesticides causes harm to the natural enemies resulting in pest outbreaks and resurgence. As an alternative, biointensive pest management combining biocontrol agents and biopesticides is gaining importance and is proved to be an ecologically sound management strategy under which parasitoids may be combined with botanicals and vice versa . Under such a condition, challenge is to find out a compatible combination. Therefore, the present investigation was aimed to evaluate relative safety of C. odorata against T. japonicum. It may be mentioned that, trichogrammatids are tiny wasps under 72 genera (Nagaraju & Ramesh, 2013) known to control various insect pests worldwide. Altogether 9 species of Trichogramma are now being mass multiplied around the world (Nagaraju & Ramesh, 2013) and utilized for the successful control of several crop pests. Moreover, botanicals isolated from more than 2000 plant species are now been mostly screened against agriculturally important insect pests because they have biodegradable, systemic, eco-friendly and non- toxic to mammals characteristics. Chromolaena odorata (L.), a widely distributed neo-tropical shrub introduced to many parts of the world is one of such plants having insecticidal properties and utilized as an indigenous technical knowledge. C. odorata acts as fumigant and toxicant to several insect pests (Acero 2014) including those of rice insects pests (Kalita et al., 2016). Materials and Methods Collection of matured leaves of C. odorata was done from their natural habitats from different areas of Jorhat district of Assam. The leaves were washed properly with double distilled water, shade- dried and powdered using an electric grinder. The leaf powders of C. odorata were passed through 60 mesh size sieve and kept in air tight containers at room temperature for the experimentation.