Reactions of four aphid species on a Russian wheat aphid resistant wheat

Results of independent tests of antibiosis, antixenosis, and tolerance with four aphid species, Russian wheat aphid, Diuraphis noxia (Mordvilko); biot ype E greenbug, Schizaphis graminum (Rondani); bird cherry-oat aphid, Rhopa losiphum padi (L.); and yellow sugarcane aphid, Sipha flava (Forbes), on ST ARS-9302W and susceptible control 'TAM W-101' confirmed the resistance of S TARS-9302W to the Russian wheat aphid, but there were no differences in the se resistance mechanisms between STARS-9302W and TAM W-101 when tested with the three other aphid species. Plant resistance index (PRI) values were gr eatest (16.7) with Russian wheat aphid tested on STARS-9302W, followed by b ird cherry-oat aphid (6.8), yellow sugarcane aphid (5.5), and Biotype E gre enbug (1.3). Greater PRI values indicate superior resistance levels. Under laboratory conditions, aphid nymphs produced/adult (X +/- SE) on TAM W-101 were greatest with greenbug (74.3 +/- 1.9), followed by Russian wheat aphid (54.1 +/- 5.2), bird cherry-oat aphid (49.4 +/- 2.1), and yellow sugarcane aphid (42.6 +/- 6.9). This is in contrast to previously reported field cag e studies where bird cherry-oat aphid was more prolific than greenbug.