NATURAL HOSTS OF RUSSIAN WHEAT APHID, DIURAPHIS NOXIA (MORDVILKO) (HOMOPTERA: APHIDIDAE), IN THE PARS PROVINCE (IRAN) AND A PREFERENCE TEST FOR THE GRASSES UNDER GREENHOUSE CONDITIONS

Investigation of potential hosts of Russian wheat aphid (RWA) revealed field infestation of twenty gramineous species. Also eighteen gramineous species were susceptible under greenhouse conditions. Preference test showed that triticale, barley, wheat, and wild oat were the most preferred hosts for RWA. There was not any significant difference of preference between triticale, barley, and wheat. However, these hosts were significantly different from other test plants. Other plant species, especially rice, corn, sorghum, and bermudagrass, were less preferred by RWA. Field observations showed that three Aegilops species, Hordeum bulbosum H., and volunteer wheat may act as a bridge between two consecutive cereal-growing seasons for RWA survival and reproduction.