Indian Journal of Natural Products and Resources Vol. 6(4), December 2015 pp. 288-292 Field study on repellent efficacy of Crotalaria burhia Buch.-Ham. ex Benth. and Anacardium occidentale L. against Odontotermes obesus (Rambur) M Ranjith 1 *, D R Bajya 1 and T Manoharan 2 1 Institute of Pesticide Formulation Technology, Gurgaon–122016, Haryana, India 2 Tamil Nadu Agricultural University, Coimbatore–641003, Tamil Nadu, India Received 9 July 2015; Accepted 5 November 2015 Crotolaria burhia Buch.-Ham. ex Benth. and Anacardium occidentale L. known for their insecticidal properties were tested for their efficacy against the subterranean termite, Odontotermes obesus (Rambur) in wheat and sugarcane fields at Institute of Pesticide Formulation Technology, Gurgaon, Haryana during 2015. Bait mixed with 10 % root extracts of C. burhia placed near 6 termitaria along the bunds of wheat field resulted in drastic decline of termite population ranging from 747.22 on 1 st day to 289.28 numbers on 12 th day after baiting. Total number of termite catch in 6 termitaria along the bunds of wheat fields after baiting period was 6704.61 whereas in untreated check it was 15078.00. Bait mixed with 5 % leaf dust of A. occidentale in sugarcane field recorded a minimum termite catch of 261.22 numbers after baiting period of 4 days, while the number was 1095.83 during prebaiting period. A total average termite population of 5655.72 was recorded in A. occidentale treated bait against 8657.67 numbers in untreated check. Termite numbers in untreated check ranged from 1277.67 to 2031.67 in wheat field and 530 to 1640 in sugarcane field. Keywords: Anacardium occidentale L., Bait, Crotalaria burhia Buch.-Ham. ex Benth., Odontotermes obesus (Rambur), Sugarcane, Termitaria, Wheat. IPC code; Int. cl. (2015.01)− A01N 27/00 Introduction An impressive increase in the research on development of bait systems for termite management has been observed over years. The rising availability of bait systems for the control of active termite infestations is already significantly assisting termite management practices in many parts of the world. There is even discussion of using such systems as stand-alone measures for the long-term protection of a structure 1,2 . Despite these important and remarkable trends, baiting is a developing technology and many more changes to existing bait technology can be expected 3 . Termites are the most troublesome pest of plants, trees and wooden structures. They severely damage agricultural crops and urban infrastructure. There are about 2,500 species of termites in the world and only 10 % have pest status. Out of 300 species in India, about 35 have been reported as damaging agricultural crops and timber in buildings. In India, 15 to 20 % yield loss is reported in maize accounting for 1,478 million INR. Severe loss by termites has been recorded on highly susceptible crops such as wheat and sugarcane in Northern India. In South India, the crops that suffer maximum damage are maize, groundnuts, sunflower and sugarcane while the victims in North Eastern and Western India are tea and cotton, respectively 4 . In the past, the control of termites has been totally based on chemicals especially synthetic insecticides such as persistent organochlorine and organophosphate insecticides 5 . Replacement of synthetic by bio-rational insecticides is universally acceptable and practical approach worldwide 6 . In this regard, bioactive compounds of plant origin are considered as ecologically safe alternatives. The plant extracts with complex mixtures of such compounds have been investigated for their insecticidal, repellent and antifeedant properties 7,8 . Because of the defense chemicals being present, these plants can be used for the development of effective insecticides against termites and thus these plant chemicals would be able to replace the persistent synthetic insecticides 9 . Crotalaria burhia Buch.- Ham. ex Benth. belonging to family Fabaceae is an undershrub, —————— *Correspondent author E-mail: entoranjith@gmail.com Mob.: 09715347877