Abstract
The laboratory experiments were conducted to study the effect of Exposure Period and Concentration of Abrasive dust (Silica gel, Limestone and Gypsum) on Killing effect of larva and adults of Trogoderma granarium Everts. under laboratory conditions (25±5Cº and 65±5% R.H) in College of Agricultural and Forestry. Mosul University 2013. The results showed that the killing percent was clearly increased So as to increased of Concentration. The Silica gel Exhibit high effective in comparison with Limestone and Gypsum which revealed after two week of treatment had higher average values of larva and adults killing which reached 60, 70.33% respectively at Concentration 70g/kg. where as these values of treatment by Limestone and Gypsum were reached 33.33, 60% and 26.66, 40% respectively at the same Concentration.
These results reflected to LC50 values of the abrasive dust which indicated that the adults had more susceptibility than larval stage in their responsable for used Dusts which LC50 values reached after two week of treatment 42.53, 58.88 and 101 ppm for Silica gel, Limestone and Gypsum respectively.
These last results reflected too on the values of Relative efficiency and Relative susceptibility of two insect stage (larva, adults) and their higher values were recorded in Silica gel after two week of adults treatment which reached 422.34 for Relative efficiency 1 for Relative susceptibility compared with Gypsum which gave lower values on larval stage which reached 100 for Relative efficiency 0.226 for Relative susceptibility.
