VIEW ARTICLE

Vector Relations

Leafhopper Transmission and Host Range of Maize Rayado Fino Virus. L. R. Nault, Professor, Department of Entomology, U.S. Department of Agriculture, Wooster 44691; R. E. Gingery(2), and D. T. Gordon(3). (2)Research chemist, Agricultural Research, Science and Education Administration, U.S. Department of Agriculture, Wooster 44691; (3)Professor, Department of Plant Pathology, Ohio Agricultural Research and Development Center (OARDC), Wooster 44691. Phytopathology 70:709-712. Accepted for publication 16 January 1980. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1980. DOI: 10.1094/Phyto-70-709.

The leafhoppers, Dalbulus maidis, D. elimatus, Stirellus bicolor, and Graminella nigrifrons, transmitted a Texas isolate of maize rayado fino virus (MRFV) to 70.0, 25.0, 11.5, and 9.7% of test corn plants, respectively, when 10 insects per plant were used. In one test, groups of five Baldulus tripsaci transmitted MRFV to two of six test plants. The leafhopper, Macrosteles fascifrons; the aphid, Rhopalosiphum padi; and the planthopper, Peregrinus maidis did not transmit MRFV. In a comparative test, the transmission rate by single D. maidis was 15.0% with a mean latent period of 16.0 days when leafhoppers acquired virus from plants, whereas the rate of transmission for leafhoppers injected with 10 μg of partially purified virus was 77% with a mean latent period of 6.9 days. Transmission efficiencies of male (10.5%) and female (9.2%) leafhoppers were similar. First instar D. maidis nymphs acquired and transmitted virus more efficiently (13.5%) than did adults (3.5%). In tests during a period of 2.5 yr, 12.0% (0–20% range) of 1,753 single D. maidis transmitted MRFV. When vector male and female leafhoppers were selected for breeding, 38.7% of 98 resultant sib 1 offspring transmitted MRFV. Of the 48 gramineous species or subspecies in 25 genera tested, only Zea mays and its teosinte subspecies, Z. luxurians, Z. diploperennis, Tripsacum australe, Rottboellia exaltata, and several Z. mays × T. dactyloides hybrids were susceptible to MRFV. The tropical weed, R. exaltata, could serve as an over-seasoning host for MRFV in the southern USA and Latin American countries. The absence of an overwintering host for MRFV may be the only factor preventing spread of MRFV to the U.S. Corn Belt, since an abundant vector, G. nigrifrons, is already present.