Disease Note

Three New Aphid Vectors of Maize Dwarf Mosaic Virus. E. B. Rest, Department of Horticulture, University of Illinois, Urbana 61801. W. E. Splittstoesser, Department of Horticulture, and C. J. D’Arcy, Department of Plant Pathology, University of Illinois, Urbana 61801. Plant Dis. 69:1100. Accepted for publication 22 August 1985. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/PD-69-1100c.

Three aphid species—Aphis citricola van der Goot, A. decepta Hottes and Frison, and A. helianthi Monell—were trapped in large numbers in fields of sweet corn (Zea mays L.) infected with maize dwarf mosaic virus (MDMV) in northern Illinois. Each of the three species was tested for its ability to transmit MDMV. Groups of 15 aphids starved for 1–2 hr were placed on sweet corn seedlings (cv. Gold Cup) infected with MDMV strain A (MDMV-A) in the center of 15.5-cm pots. Each infected seedling was clipped off before the pot was caged to encourage migration to six uninoculated seedlings near the perimeter of the pot. After 24 hr of inoculation access, all plants were sprayed with pirimicarb (Pirimor); 10–14 days later, plants were evaluated visually and by enzyme-linked immunosorbent assay. MDMV-A was transmitted to 23 of 167 plants by A. citricola, to two of 31 plants by A. decepta, and to five of 64 plants by A. helianthi. No infected plants were found in pots with aphids with no virus source. Tests with individual aphids are needed to determine transmission efficiencies of the three species.