GC-MS profiling and efficacy of Crotalaria ramosissima Roxb. leaf extracts in controlling termite, Odontotermes obesusH. A. LANCHANA1, S. BASAVARAJAPPA2 and RAJKUMAR H. GARAMPALLI1*1Department of Studies in Botany, University of Mysore, Manasagangotri, Mysore – 570006, Karnataka, India2Department of Studies in Zoology, University of Mysore,Manasagangotri, Mysore – 570006, Karnataka, India*Corresponding author E-mail: rajkumarhg@gmail.comINTRODUCTIONSome aromatic plants and their extracts have been used to control pests since ancient times and from historical sources it is evident that, in Europe and other countries aromatic plants are used particularly in grain storage rooms during post-harvest time (Pavela, 2016). Plant extracts are used for many beneficial activities and pest control is one of them. Plants and insects co-evolved with different survival strategies, resulting in the development of an elegant defence mechanism in which active metabolites are released in response to herbivores from specific structures which are toxic, repellent, or anti-nutritional to some animals and humans (Rani it does not occur in the Western Ghats (Subramaniam Subramaniam et al., 2015; Thomas et al., 2012). Village people use it for foraging and as pest control in grain storage rooms. C. ramosissima flowers are already reported for flavanone, crotaramosmin, trimethoxychalcone, and essential oil major component like sesquiterpenes. However, their biological activities are not known (Khalilullah et al., 1992; Rao & Narukulla, 2007).494

Crotalaria ramosissima Roxb. is a Fabaceae family genus that prolifically grows as a weed in southern regions of India and is known for insect-repellent activity. The purpose of the current study is to assess the efficacy of anti-termite activity of the different solvents extracts and formulations of C. ramosissima against Odontotermes obesus which is prevalent in the south dry zone that destroys 10% of crops and wood on an average by feeding. The extracts showed anti-termite efficacy by No-choice bioassay method where the ethyl acetate extract showed highest termite mortality rates of 24.23±1.51%, 43.93±1.51%, 74.23±1.51% at 12, 24, 36h time intervals and methanol extract showed 16.66±1.51%, 30.29±4.00%, 54.54±2.62% at 12, 24, 36 h time intervals. The TLC analysis of ethyl acetate extract resulted in three bands which were separated through column chromatography and named Fraction-1, Fraction-2, and Fraction-3 and upon further investigation Fraction-3 showed maximum mortality rate of 81.81±2.62% at 36 hrs of time interval with a lethal concentration (LC-50) 248.44mg/ml. The GC-MS profiling of fraction-3 led to the identification of compounds viz. 1,2-benzenedicarboxylic acid, 1,2,4-oxadiazole, 3-(1,3-benzodioxol-5-yl)-5-2-(4-methoxyphenyl)ethyl, phenmethylamine-2-acetoxy-n,n-bis[2-(benzoimid-2-yl)ethyl, and 9-octadecenoic acid (z)-2-hydroxyethyl ester and phenol, p-(1-ethyl-1-methylbutyl.These results may aid in the synthesis of novel effective bioactive compounds that needs to be explored for their toxicity against insects, as was enlightened in the current study