Abundance Of Insects And Mites Infesting Stored Grain And Animal Feed In Riyadh And Dammam Provinces, Saudi Arabia

Abstract

Insects and mites infesting wheat, maize and wheat bran, stored in plants at Riyadh and Dammam, Saudi Arabia, were scanned in 2 seasons, 1987 and 1988. Grains from the local markets and dust from both provinces were also surveyed. Infestation of these commodities by a granivorous group of pests, expressed as least squares means of sum of the pests, was found to be dependent upon factors of season, province, height inside bin, type of commodity and storing/sampling period within season (main effects and interactions). Infestation differed pronouncedly according to the factors included in 9 models selected for comparison. Accordingly, to predict infestation of stored commodities by granivorous pests, it was recommended to specify storage conditions precisely. Infestation by another non-granivorous group of pests was, in most cases, not affected by the factors studied. The latter group included predators and parasites of extreme importance, thus their role in suppressing infestation by the granivorous species requires detailed study.