EFFICACY OF SYNTHETIC PESTICIDES AND PLANT EXTRACTS AGAINST RIPTORTUS PEDESTRIS FABRICIUS (HEMIPTERA: ALYDIDAE)

Abstract

Riptortus pedestris (Fabricius) (Hemiptera: Alydidae) is a newly introduced polyphagous sap sucking and one of the major pests of leguminous crops worldwide. Current management strategy of R. pedestris relies upon frequent applications of pesticides. Pesticides use not only directly affects pest populations through acute toxicity but also has indirect (sub lethal) effects on pest physiology or behavior. In this study, efficacy of synthetic pesticides and plant extracts against R. pedestris were studied. Among these pesticides, Clorpyrifos + Cypermethrin and Cypermethrin were found highly toxic by topical application as well as exposure to residue which caused 100% mortality within 4 hours after treatment. Clorpyrifos + Cypermethrin and Cypermethrin also caused 100% mortality within 8 hours by residue on substrate. Therefore, for the integrated pest management program, Clorpyrifos + Cypermethrin, Cypermethrin and Profenos Q + Cypermethrin can be use to control the R. pedestris in field condition. In case of plant extracts, the maximum mortality (100%) of adults was recorded at 48 hours after treatment while sprayed with Neem and Crown flower topically @ 700 mg/L. The mortality value decreased chronologically while treated with Water pepper and Marigold at 54 hours after treatment at the same dose. Additionally, at residual method the maximum mortality (100%) of adults was recorded while at applied Neem at 48 hours after treatment @ 700 mg/L. The repellency test showed the toxic effects and among the plant extracts the performance of neem was acute and it posses the class III repellency followed by Water pepper and Marigold. However, Neem and Crown flower extracts showed highly potential to control the R. pedestris and can be use as alternative of synthetic chemical pesticides.