Study was conducted in two identical horizontal (flat) Storages. One of the tested storages was treated by Aluminum Phosphide (fumigant) insecticide and the other storage was untreated. An array or regular grid of pheromone traps was placed in both storages for Sitotroga cerealella (Olivier) moths population monitoring. Contour maps was created using Geographic Information System (GIS) ArcView® 3.2.   An average of 16.014/trap S. cerealella moths were found during the entire sampling period in both untreated and treated (fumigated) storages. Results indicated that S. cerealella moth population was much higher in the untreated storage 15.838/trap during the entire study period compared to the treated storage 0.175/trap due to the great impact of phosphine treatment. Pheromone trap counts in the untreated storage indicated that the greatest mean monthly number of captured moths was 41.0/trap occurred in July, while the lowest number of captured moths was 0.2/trap recorded in December (Table 1). In comparison to the storage treated with phosphine number of trap catch was significantly low due to potential effect of the fumigant as a control method, the highest number of S. cerealella moths captured in pheromone traps was 0.583/trap observed in August, while zero moths was recorded in December. Contour maps illustrated that the source of moths infestation found in the center of the storage in the beginning of spring months. Subsequently, contour maps showed that the hot spot spread through the entire untreated storage during summer months. While, it was still in the center with samller number of captured moths in the treated storage. Then, in both storages infestation went back to the center of the storage during the autumn months tell reached to the lowest number of trap catch during December.  Trapping provides an effective method for detecting stored product insects in buildings (e.g., warehouses, processing plants, and retail stores), and when combined with contour analysis of trap catch, it is also provides a convenient means of locating source of infestation. Trapping with contour mapping provides permanent documentation of pest problems and their management, which can be useful for decision making in the integrated pest management.