Diatomaceous Earth (DE) is an approved and registered product for use against indoor and outdoor crawling insects. DE is odorless and nontoxic, composed of finely milled fossilized shells of minuscule organisms which present microscopically fine, sharp edges that desiccate the insects' exoskeleton upon contact and dehydrating the insects within hours. The chemical analyze of Rive Hull Ash (RHA) showed percentage of SiO2 of 96,65%, having as main impurities K2O, CaO, Al2O3, MgO and P2O5, and the mineralogical analysis that the ash presents silica in the (reactive) or crystalline (practically inert) form, directly relate to the temperature and the method of attainment of the ash. The microscopical structure of RHA is similar to that of DE. The objective of Kannenberg Ltda. and the University of Santa Cruz do Sul in conducting this project was to compare the effectiveness of DE and RHA on the population of Lasioderma serricorne (L.s.) in tobacco warehouses in the region of Santa Cruz do Sul, RS, Brazil. Lasioderma serricorne (F.) ( Insecta, Coleoptera, Anobiidae ), a common pest found in stored products, was monitored by pheromone traps in all tested warehouse and laboratory settings. The field work was carried out at Kannenberg Ltda. and in farms of associated tobacco growers in southern Brazil. All laboratory and field treatments with DE (2001 to 2005) showed that DE represents a possibility to control the population of L.s., provoking a significant reduction (50-83%) of the number of individuals. Together with conventional techniques DE is an alternative to control this tobacco pest. The tests with RHA (2004 to 2005) indicate the effectiveness to control L.s. in laboratory as well as in field condition, dandifying the exoskeleton upon contact and dehydrating the insect, similarly to DE. Both products show the highest effectiveness in dry application provoking a decrease (50-91%) of the population of L.s. in tobacco warehouses at Kannenberg and at growing sites.