Lethal and knock down toxicity of plant glycosides and study of its effects on the life cycle of Oberea

Oberea brevis Swed. (Girdle beetle) is the common serious insect pests of soybean. It has been found that about 75% of the plants get totally damaged when this insect attacks. In the present investigation quercitrin glycoside of Trigonella foenum-graecum and flavonol glycoside of Abrus precatorius was tested for Lethal and Knock down toxicity against 4th instar larval stage Oberea brevis. The values of LC100, LC50, LC0 and sub-lethal concentration were detected out and data was summarized in table 4–5. The time in hrs for KD100, KD50 and KD0 were detected out and were summarized in table 6–7. Results indicated that flavonol glycoside -3,4 ′dihydroxy-7,3 ′,5 ′-trimethoxy, flavone-3-O- β-D-galactopyranosyl(1 → 4)-O-α-L-xylopyranoside had a higher toxicity on 4th instar larval stage Oberea brevis than quercitrin glycoside. Also, present investigation has been taken to study the effect of glycosides extracted from Abrus precatorius and Trigonella foenum-graecumon the life cycle of Oberea brevis.