INSECTICIDAL EFFICACY OF TURKISH NOVEL DIATOMACEOUS EARTH FORMULATIONS AGAINST COWPEA WEEVIL Callosobruchus maculatus (F.) (COLEOPTERA:CHRYSOMELIDAE:BRUCHNINAE) ON CHICKPEA

Abstract

In present study, insecticidal efficacy of two newly developed Turkish diatomaceous earth (DE) formulations, Detech (R) and Demite (R), and commercial formulation, Silicosec (R) was tested against cowpea weevil, Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae: Bruchninae) adults on chickpea. Biological tests were performed under laboratory conditions (26 +/- 1 degrees C and 65 +/- 5 % r.h.), by exposing 24 h old adults to chickpea grains treated with Detech (R), Demite (R) and Silicosec (R) at six concentrations (500, 750, 1000, 1500, 2000 and 2500 mg DE/kg grain) and an untreated control. Adult mortality was assessed after 1, 3, 5 and 7 d of exposure, while number of F1 progeny was assessed after 42 d of DE treatments. Biological tests indicated that only Detech (R) achieved 100% mortality after 1 d of exposure at 2500 ppm, while Detech (R) Demite (R) achieved 100% mortality after 3 d of exposure at >= 1500 ppm and 2500 ppm respectively. Detech (R) achieved 100% mortality after 5 d of exposure at 750 ppm and above DE concentrations while Demite (R) resulted in the 100% mortality at >= 1000 ppm. The efficacy of tested DE formulations ranked in decreasing order of efficacy against C. maculatus: Detech (R)> Demite (R)>Silicosec (R). The complete progeny suppression of C. maculatus was achieved only with Detech (R) treatment at 2500 ppm, while Demite (R) and Silicosec (R) treatments at 2000 and 2500 ppm caused more than 98% progeny suppression. In conclusion, these results suggest that novel Turkish DE formulations, Detech (R) and Demite (R), which consists of a mixture of three DE deposits, consisted of different diatom Pustules has great potential for effectively use against C. maculatus in stored chickpea.