Repellent Activity of the Essential Oil from Capparis tomentosa against Maize Weevil sitophilus zeamais

Abstract

Essential oil was extracted from the fresh leaves of C. tomentosa through hydro-distillation, using a Clevenger type apparatus. Analysis of the oil was carried out on a combined gas chromatograph-mass spectrometer fitted with an hp-5 ms (5% phenyl methyl siloxane) column at a temperature programme of 35°c (5 min) increased at 10°c/min to 280°c and held for 10.5 min then 50°c/min to 285°c. The individual components of the essential oils were identified through GC, GC-MS and GC-FID co injection with the authentic standards. The major components identified include: beta phellandrene 26.63%, beta pinene 15.34%, euginol 6.64%, terpineol 6.02%, terpinen-4-ol 5.24%, ?-cymene 3.19%, geraniol 4.14%, nerolidol 5.14%. The repellent action of the essential oil was also evaluated using a Y shaped olfactometer.  The data obtained was analyzed using statistical analysis system (sas).  The repellent ability of the components of the essential oil from c. tomentosa: Nerolidol and Linalool showed significant repellence at all doses. The oil together with its components Nerolidol and Linalool may be good choices for repellant formulations

Keywords: C. tomentosa, Sitophilus zeamais, Essential oil, Insect repellent, GC-MS.