Pantnagar Journal of Research

Abstract

Laboratory experiments were conducted to study the long-term efficacy of 141 formulations of herbal fumigants against Rhyzopertha dominica and Tribolium castaneum. The herbal fumigants were formulated by compounding the essential oils of Mentha arvensis, Mentha piperita, Mentha spicata, Cymbopogon winterianus, Eucalyptus citriodora, Curcuma longa and Pinus roxburghii at different concentrations. All seven essential oils were studied at 0.20 and 0.40 per cent (v/w) while their two, three, four, five, six and seven component combinations were evaluated at 0.20, 0.14, 0.10, 0.08, 0.07 and 0.06, per cent (v/ w) each. Some other formulations such as M. piperita + C. longa, M. piperita + P. roxburghii, C. longa + P. roxburghii, C. longa + M. arvensis and P. roxburghii + M. arvensis were also evaluated at 0.10+0.10 per cent each while C. longa + M. arvensis and P. roxburghii + M. arvensis were tested at 0.30+ 0.10 per cent against both the insects. The test insects were reared on the grain treated with different formulations. The number of progenies produced by 10 adult insects were counted after 469 and 446 days, in case of R. dominica and T. castaneum, respectively. Inhibition of progeny by test formulation was calculated by using the number of adults emerged in treated and untreated grain. No adult of R. dominica emerged in any of the treatment after 469 days while 386 adults emerged from untreated grain. In case of T. castaneum, 153.3 adults emerged from untreated grain after 446 days while treated grain did not permit any adult. The results indicated that all the formulations of herbal fumigants completely checked the progeny production of both the insects for more than a year.