Development and Reproduction of the English Grain Aphid (Homoptera: Aphididae) on Wheat Cultivars Infected with Barley Yellow Dwarf Virus

Abstract

Interactions among the English grain aphid, Macrosiphum (Sitobion) avenae (F.), and three wheat ( Triticum aestivum L.) cultivars infected with two isolates of barley yellow dwarf virus (BYDV) were investigated under laboratory conditions by caging individual aphids on leaves of healthy ‘Caldwell,’ ‘Abe,’ and ‘Talento’ wheat plants or plants infected with BYDV (P-PAV and RPV-NY isolates). M. avenae feeding on infected wheat had a significantly shorter (P ≤ 0.05) developmental time, a greater fecundity, and a greater intrinsic rate of natural increase ( r m) than aphids feeding on noninfected plants. These results suggest that BYDV and M. avenae interact for their mutual benefit, resulting in a higher potential for population growth of the virus and the vector. The wheat cultivar ‘Caldwell’ was found in this and previous studies to have a degree of tolerance to BYDV as indicated by milder symptoms. Resistance to virus production also was detected for the P-PA V-infected ‘Caldwell’ wheat, which had significantly lower ELISA values (i.e., lower virus concentration) than ‘Abe’ wheat. M. avenae also had a significantly reduced fecundity on ‘Caldwell’ compared with that on ‘Abe’ and ‘Talento’ wheats infected with BYDV. No significant differences were observed in M. avenae fecundity on BYDV-free cultivars. The results suggest that infection with BYDV might improve the nutritional quality of wheat to M. avenae , resulting in changes in the fecundity of the vector. These changes were greater with the BYDV-sensitive ‘Abe’ and ‘Talento’ cultivars than with the tolerant ‘Caldwell’ wheat cultivar.