Evaluation of infestation by cereal leaf beetles (Oulema spp.) on six varieties of durum wheat (Triticum dirum, Desf.) seedlings in arid conditions of Setif, Algeria

The abundance of cereal leaf beetle on six durum wheat varieties (Triticum durum Desf.) and the influence of leaf flags infestation on grain yield per spike were studied. The results show the existence of two species of beetle at the experimental site (ITGC, Setif), namely Oulema melanopus and Oulema hoffmannseggi. The study shows also, that varieties tested were infested at different rates and there is a negative effect between the infestation rate of the flag leaf and grain weight per ear. Thus, the rate of loss of grain per spike ranged range from 3.48% in Boussellam variety to 23.15% in Megress variety if the infestation rate of the flag leaf is less than 10%, then the rate of loss in grain per spike can vary between 29.35% in Boussellam to 85.71% in Ofanto if the infestation rate of flag leaf is greater than 40%.