The efficiency of the insecticide Agrothrin (0.11% Pyrethrum) as well as certain dusts of the natural materials, i.e. blackpepper seeds, dill seeds chili fruits and sodium chloride were evaluated separately and in combinations with Agrothrin against the adults
of Sitophi lus oryzae (L.), Rhizopertha dominica (F.) and Triholium castaneum (Herbst.). Tests were carried out in the laboratory at 25±2
°C and 55±5% RH. The results indicated that dusts of chili fruits and sodium chloride were obviously less effective against the three
insect species than the other tested materials. In general, Triholium ca.vtaneum was the most tolerant species against the tested products.
Adult mortality was positively correlated with the increase of the exposure period and material concentration. Mixtures of black pepper,
chili fruits, and sodium chloride dusts showed at concentrations between I and 8% w/w with Agrothrin at 2ppm pronounced less effect on
the adult’s mortality of S. oryzae compared with the using of the each dust alone at various tested exposure periods. Meanwhile, similar
effects were obtained for R. dominica with mixtures of black pepper, chili fruits and dill seed dusts with the exception of sodium chloride
mixtures, which were more effective on adult mortality. In case of T castaneum, less effect on the adults’ mortality was noticed, when the
adult insects were treated with the different mixtures of black pepper and dill seed dust with Agrothrin at various periods of exposure
compared with the use of each dust alone, while the mixtures of chili fruits and sodium chloride with Agrothrin showed a very high effect
on adults’ mortality.
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