Insecticidal efficacy of diatomaceous earth against Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

Laboratory bioassays were carried out to evaluate the insecticidal efficacy of SilicoSec? against ۷ - ۱۴ day old adults, old and young larvae of Tribolium castaneum (Herbst) with the mean ? SE (n = ۳۰) weight of ۳.۴ ? ۰.۱ and ۰.۶ ? ۰.۱ mg, respectively at ۲۷?C and ۵۵ ? ۵% RH. Wheat treated with four dose rates of SilicoSec? and untreated wheat served as a control with three replications. Adult?s mortality was measured after ۲, ۷ and ۱۴ days of exposure. After ۱۴ day mortality counts, all adults were removed and samples retained under the same conditions for a further ۶۰ days to assess progeny production. In the case of larvae, mortality was counted after ۱, ۲ and ۷ day. After ۲ day no concentration achieved ۱۱% mortality for adults, however; adult's mortality exceeds ۸۹.۶۵% when exposed for ۷ day to SilicoSec?. Mortality of old and young larvae at ۶۰۰ ppm after ۲ day were ۲۸.۸۸ and ۲۲.۲۲%, respectively and exceed to ۶۰.۷۱ and ۶۹.۰۴% at longer exposure of ۷ day. Due to results mortality of T. castaneum was influenced by interval exposed to wheat treated with SilicoSec? and over this exposure, the increases in application rate of SilicoSec? had significant effect on the mortality. Young larvae of red flour beetle were more sensitive to SilicoSec? than old larvae and adults were more tolerant. The mean number ? SE of progeny in the control was ۱.۶۶ ? ۰.۱۰۱ individuals per vial and there was a significant difference between treated and untreated wheat, so reproductive potential of adults in treated wheat was suppressed when compared with untreated wheat.   REFERENCES  Abbott, W.S., (۱۹۲۵) A method of computing the effectiveness of an insecticide. J. Econ. Entomol. ۱۸, ۲۶۵-۲۶۷. Aldryhim, Y.N., (۱۹۹۰) Efficacy of the amorphous silica dust, Dryacide, against Tribolium confusum Duval and Sitophilus granaries (L.) (Coleoptera: Tenebrionidae and Curculionidae). J. Stored Prod. Res. ۲۶, ۲۰۷-۲۱۰. Aldryhim, Y.N., (۱۹۹۳) Combination of classes of wheat and environmental factors affecting the efficacy of amorphous silica dust, Dryacide, against Rhyzopertha dominica (F.). J. Stored Prod. Res. ۲۹, ۲۷۱- ۲۷۵. Arnaud, L., Lan, H.T.T., Brostaux, Y and Haubruge, E., (۲۰۰۵) Efficacy of diatomaceous earth formulations admixed with grain against populations of Tribolium castaneum. J. Stored Prod. Res. ۴۱, ۱۲۱-۱۳۰. Arthur, F.H., (۲۰۰۰) Toxicity of diatomaceous earth to red flour beetles and confused flour beetles (Coleoptera: Tenebrionidae) effects of temperature and relative humidity. J. Econ. Entomol. ۹۳, ۵۲۶–۵۳۲. Athanassiou, C.G., Vayias B.J., Dimizas G.B., Kavalieratos N.G., Papagregoriou A.S. and Buchelos C.Th. (۲۰۰۵) Insecticidal efficacy of diatomaceous earth against Sitophilus oryzae (L.) (Coleoptera: Curculionidae) and Tribolium confusum Du Val (Coleoptera: Tenebrionidae) on stored wheat: Influence of dose rates, temperature and exposure interval. J. Stored Prod. Res. ۴۱, ۴۷-۵۵. Fields, P.G., Korunic, Z., (۲۰۰۰) The effect of grain moisture content and temperature on the efficacy of diatomaceous earths from different geographical locations against stored-product beetles. J. Stored Prod. Res. ۳۶, ۱-۱۳. Golob, P., (۱۹۹۷) Current status and future perspectives for inert dusts for control of stored product insects. J. Econ. Entomol. ۹۰, ۶۹-۷۹. Korunic, Z., Fields P.G., Kovacs M.I.P., Noll J.S., Lukow O.M., Demianyk C.J. and Shibley K.J. (۱۹۹۶) The effect of diatomaceous earth on grain quality. Postharv. Biol. Technol. ۹, ۳۷۳–۳۸۷. Korunic, Z. (۱۹۹۸) Diatomaceous earths, a group of natural insecticides. J. Stored Prod. Res. ۳۴, ۸۷–۹۷. Pixton, S.W. and Warburton, S. (۱۹۷۱) Moisture content/relative humidity equilibrium of some cereal grains at different temperatures. J. Stored Prod. Res. ۶, ۲۸۳-۲۹۳. SAS, ۲۰۰۰. The SAS System version ۷ for Windows. SAS Institute, Cary, Nc. SPSS, ۱۹۹۹. SPSS for Windows User’s Guide Release ۱۰. SPSS Inc. Chicago Vayias, B.J., and Athanassiou, C.G. (۲۰۰۴) Factors affecting the insecticidal efficacy of the diatomaceous earth formulation SilicoSec against adults and larvae of the confused flour beetle, Tribolium confusum Duval (Coleoptera: Tenebrionidae). Crop Prot., ۲۳, ۵۶۵-۵۷۳.

Keywords:

Diatomaceous earth , Grain protectant , SilicoSec? , Tribolium castaneum , Wheat