duration of life stages and fecundity of diuraphis noxia (hemiptera: aphididae) on six wheat cultivars

the russian wheat aphid (rwa), diuraphis noxia has been known as a major pest of small grains, particularly wheat, worldwide. this study evaluated the biological responses of rwa to six wheat cultivars including yavarus, pishgam, aadl, omid, darab 2 and sepahan. the experiment was conducted under greenhouse conditions of 25 ± 2 °c, 55 ± 10 % r. h. and a photoperiod of 16:8 (l: d) h. resistance or susceptibility of cultivares against the aphid nymphal development time, adult fecundity, daily reproduction, total longevity and adult longevity were investigated. the anova of the data indicated that there were significant differences (p < 0.05) among cultivars regarding duration of nymphal development time, fecundity and daily reproduction. the longest mean nymphal development time was obtained on omid and sepahan, and the shortest on yavarus. the highest and the lowest total fecundity were observed on yavarus and omid, respectively. also, the highest and the lowest mean offspring produced per female per day (daily reproduction) was observed on yavarus and omid, respectively. on the whole, yavarus appeared to be susceptible to the russian wheat aphid while omid was resistant.