Insecticidal activity of the root extract of Decalepis hamiltonii against stored-product insect pests and its application in grain protection

Root extracts of Decalepis hamiltonii were
tested for insecticidal activity against the stored products
pests, Rhyzopertha domonica, Sitophilus oryzae, Stigobium
pancieum, Tribolium castaneum and Callosobruchus chinensis,
in residual and contact toxicity bioassays. Methanolic
extract showed LC
50
value of 0.14 mg/cm2 for all the
test species in a fi lter paper residual bioassay. The extract
was effective as a grain protectant for wheat and green
gram. Reduction of F1 progeny was observed in treated
grain stored for 3–4 months. The extract did not affect the
germination of the treated grains. Our results indicate that
methanolic extracts of D. hamiltonii has a potential to control
stored product pests and could serve as a natural grain
protectant.