REPELLENCY OF RED FLOUR BEETLE, TRIBOLIUM CASTANEUM CAUSED BY LEAVE EXTRACT FRACTIONS OF HILL TOON, CEDRELA SERRATA

Abstract

The plant origin pesticides have recently got great importance than the synthetic pesticides, against stored grains pests because of their lesser hazards to the environment and other related biomass. The present research was conducted to evaluate the repellency of 5^th instars of the red flour beetle, Tribolium castaneum (Herbst.) caused by 5 doses of 4 fractions of the hill toon, Cedrela serrata Royle leaves extract after consecutive 1 h interval for 5 h by 2 methods. Tribolium castaneum was reared under controlled laboratory conditions at 30±1 °C, 60±2% RH and a 16:8 h (L:D). In method “A”, at the highest dose, i.e., 40.8 µl/cm², the fractions of leaves extract showed repellencies belong to the classes: n-butanol fraction (repellency: 92.2±6.2; class: V) > ethyl acetate fraction (repellency: 74.8±8.3; class: IV) > methanolic extract (repellency: 67.2±8.6; class: IV) > aqueous fraction (repellency: 46.4± 8.3; class: III). In method “B”, at the same dose, the same fractions showed repellencies belong to the classes: n-butanol fraction (repellency: 22.0±10.7; class: II) > ethyl acetate fraction (repellency: 20.4±7.3; class: II) > methanolic extract (repellency: 19.0±11.0; class: I) > aqueous fraction (repellency: 6.0±22.5; class: I). Repellency increased with increase of doses, however, it decreased with increase of duration of time. Method “A” was more significantly effective than method “B”. The n-butanol fraction was the most effective than other fractions. Further research should be conducted on C. serrata to isolate its active compound and to use it on commercial bases against T. castaneum.