Abstract
Experiments were conducted to compare the expression of Russian wheat aphid,
Diurnphis noxia (Mordvilko), resistance in 2 genotypes of tall fescue grass,
Festucn arundinacea Schreb., harboring different isolates of the endophytic fungus
Acremonium coenophialum Morgan-Jones & cams. Aphids did not select endophyte-free over endophyte-infected tiller sections in laboratory tests. In a laboratory population growth test, aphid numbers declined for 2 d on all endophyte-free plants and then increased. Aphid mortality was 100% on all infected plants after 4 d. Thus, antibiosis resistance to
D. noxia was not specific to tall fescue genotype or to Acremonium isolate. In a field plot, numbers of Russian wheat aphids were significantly higher on endophyte-free tall fescue. Using these results, and results of other studies involving Acremonium-enhanced resistance to
D. noxia in tall fescue and other host grasses, the potential for using
D. noxia to screen grass germplasm for
Acremonium fungiis discussed.
Keywords
aphids,
Diuruphis noxia,
Acremonium fungi,
grass,
plant resistance
Citation
Clement, S.L.; Lester, D.G.; Wilson, A. Dan; Johnson, R.C.; Bouton, J.H. 1996. Expression of Russian Wheat Aphid (Homoptera: Aphididae) Resistance in Genotypes of Tall Fescue Harboring Different Isolates of
Acremonium Endophyte. J. Econ. Entomol. 89(3): 766-770 (1996)