Damage evaluation of cereal stem sawfly, Cephus pygmaeus, on common cultivars and promising lines of wheat and a cultivar of barley

C Cereal stem sawfly, Cephus pygmaeus (Hym: Cephidae), is an important wheat pest. The pest larvae feed inside wheat stems and cause damage. This project was carried out in a completely randomized block design with 7 treatment and 3 replications (21 plots, 3 m×4 m) in Farim region, Sari, Iran, during 2015-2016. Evaluation of damage caused by the pest on two common wheat cultivars (Morvarid and Gonbad), four promising wheat lines (N91-9, N91-10, N91-14 and N91-17) and one barley cultivar (Sahra) were investigated. On harvesting time, all plants located in 1 m2 of each plot were sampled including their roots. The numbers of infested stems were counted and percentage of infestation measured. Diameter of 20 intact and 20 infested stems, 100 kernel weights of healthy and infested plants and the grain weight of 1 m2 of each plot were measured. Data were analyzed by MSTAT-C software and the means were compared using Tukey test. Regarding the percentage of infestation, there was no significant different between the common cultivars and the promising lines of wheat. However, the barley cultivar (Sahra) had significantly less infestation compare to wheat treatments.