Efficacy of essential oils against American cockroach

The toxicity, repellency and fumigant activity of three essential oils were evaluated against the Periplaneta americana (L.) under laboratory conditions. The essential oil of C. citratus exhibited complete repellency (up to 100%) against P. americana using different concentration (4, 5, 6 and 7%) after 24 hours. LC50 value for C. citratus is 8.013, 7.050, 4.897 and 3.391 at 2, 4, 6 and 24 hours. Fumigant activity ranging from 70-100% was observed using C.citratus under laboratory conditions against P. americana. Satisfactory toxicity 10-100% was found using Mentha arvensis at different concentrations between different time interval (2-24 hours). In case of M.arvensis LC50 value for contact toxicity is 8.122, 8.013, 6.004 and 4.640 after 2,4, 6 and 24 hours. Fumigation value ranges from 50-80% was seen in case of M.arvensis at different concentrations. Least toxicity, repellency and fumigant activity was observed in case of Eucalyptus citrodora. %age mortality from 0-80% was achieved between 2-24hours at different concentrations. LC50 value is 8.268, 10.292, 7.050 and 4.814 after 2, 4, 6 and 24 hours. 40-60% fumigant activity was observed after 24 hours at different concentrations.