COMPARISON OF HOST SUITABILITY OF WESTERN WHEAT APHID WITH THE RUSSIAN WHEAT APHID

Authors: Kindler, Dean - Dean; HAMMON, ROBERT - COLO STATE UNIV, FRUITA

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/9/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary: The western wheat aphid and the Russian wheat aphid are pests of wheat, and both species share similar distribution patterns in the United States. However, the Russian wheat aphid is a perennial economic pest of wheat, where the western wheat aphid is, at most, an occasional economic pest of wheat. The economic importance of the Russian wheat aphid depends in part on its ability to use plant species as alternative and oversummering hosts We studied the survival and reproduction of western wheat aphid on numerous cool- and warm-season grasses, legumes, and forbs, and also compared the western wheat aphid with the Russian wheat aphid on brome grass species and wheatgrass species to see if the two aphid species differ in their reproduction and survivorship on the same grass species. Although the western wheat aphid could reproduce and survive on a number of cool- and warm-season grasses, the natality of the western wheat aphid compared with the Russian wheat aphid on the brome grass species and wheatgrass species was generally significantly lower for the western wheat aphid than the Russian wheat aphid. In addition we found that the western wheat aphid was much more difficult to rear than the Russian wheat aphid under the same environmental conditions, indicating the western wheat aphid was much more sensitive to its environment than the Russian wheat aphid. Information gained from this study established important baseline data on the western wheat aphid which can be used to monitor for virulent biotype development.

Technical Abstract: The western wheat aphid, Diuraphis tritici, and the Russian wheat aphid, D. noxia, are pests of wheat, Triticum aestivum L., and both species share similar distribution patterns in the United States. D. noxia is a perennial economic pest of wheat, where D. tritici is, at most, an occasional economic pest of wheat. The economic importance of D. noxia depends in part ton its ability to use plant species as alternate and oversummering hosts. We studied the survival and reproduction of D. tritici on numerous cool- and warm-season grasses, legumes, and forbs, and also compared D. tritici with D. noxia on some common Bromus and Agropyron spp. to see if the two aphids differ in their reproduction and survivorship on the same grasses. D. tritici survived on 36 of 40 cool-season grasses, 7 of 19 warm-season grasses, and none of the 33 legumes or 13 forbs. The natality of D. tritici compared with D. noxia on several species of brome grasses and wheatgrasses swas generally significantly lower for D. tritici than D. noxia. D. tritici preferred wheat over 3 other cereals, whereas wheat and barley were equally suitable as hosts for D. noxia. Rye was essentially a non-host for the D. tritici. Aphid populations after 14 d were significantly higher for D. noxia on all 4 cereals compared with D. tritici populations on the same hosts. In a separate experiment to compare damage of D. tritici with D. noxia on different growth stages of wheat, D. tritici was significantly more deleterious to the yield potential and components of wheat, particularly when infested at the 7-leaf and jointing growth stages, than D. noxia. The economic importance of D. noxia compared with D. tritici to U.S. wheat production may be due in part to its ability to survive and increase on cool-season grasses and cereals better than D. tritici.