Comparative toxic potential of some plant extracts and spinetoram against Tribolium castaneum (Herbst, 1797) (Coleoptera: Tenebrionidae)

The comparative toxicity of lemon grass, Cymbopogon citratus (Stapf) (Poales: Poaceae); neem, Azadirachta indica (A. Juss.) (Sapindales: Meliaceae); castor oil plant, Ricinus communis (L.) (Malpighiales: Euphorbiaceae); and yellow oleander, Thevetia peruviana (L.) Lippold (Gentianales: Apocynaceae) and spinetoram alone and in combinations were evaluated against Tribolium castaneum (Herbst, 1797) in the Entomology Laboratory of Punjab Bioenergy Institute, University of Agriculture, Faisalabad, Punjab, Pakistan from May to October, 2018. Different concentrations of plant extracts (5, 10 and 15%) and spinetoram (0.01, 0.02 and 0.03%) were applied in filter paper toxicity bioassay. The results of single applications of all treatments showed that spinetoram was more effective with the highest mortality of 79.8% by followed by 57.9% for A. indica, 49.5% for C. citratus, 40.1% for T. peruviana and 28.9% for R. communis extracts. In combinations, A. indica + spinetoram gave the highest mortality of 84.9% with a lower mortality of 25.2% observed for R. communis + spinetoram. LC50 values of spinetoram were comparatively low indicating that it is the more toxic than the plant extracts. Overall the results indicated that these plant extracts and spinetoram can be used as combined form in IPM for the efficient management of insect pests of stored grains