First Report in Virginia of Dicyma pulvinata Colonizing Cercosporidium personatum, the Causal Agent of Late Leaf Spot of Peanut. D. M. Porter, USDA-ARS, Tidewater Agricultural Experiment Station, Suffolk, VA 23437, and 210 Forest Avenue, LaVale, MD 21502. R. A. Taber, USDA-ARS, Tidewater Agricultural Experiment Station, Suffolk, VA 23437, and 210 Forest Avenue, LaVale, MD 21502. Plant Dis. 76:1185. Accepted for publication 10 August 1992. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/PD-76-1185B.
Dicyrna pulvinata (Berk. & M.A. Curtis) Arx, a hyperparasite, was observed colonizing lesions of peanut (Arachis hypogaea L. 'NC 6) caused by Cercosporidiurn personaturn (Berk. & Curtis) Deighton, the late leaf spot pathogen. Lesions caused by Cercospora arachidicola S. Hori, the early leafspot pathogen, were not colonized. On 14 October 1991, approximately 2,000 leaflets were collected at random from a Suffolk, Virginia, peanut field. Cercospora arachidicola caused 1,784 leaflet lesions and Cercosporidiurn personaturn, 8,110. Each lesion was observed microscopically (I0-40X) for evidence of colonization by D. pulvinata. Late leaf spot lesions on the abaxial surface of the leaflet were colonized by D. pulvinata at a frequency of 2.5%. Colonization of the adaxial surface lesions by D. pulvinata was associated with colonization of the abaxial surface, but some adaxial colonizations (0.2% of the total colonized leaflets) were not associated with abaxial colonizations. This is the northernmost report of D. pulvinata colonizing lesions caused by C. personaturn on peanut leaflets in the United States and is the first report of this hyperparasite of C. personaturn occurring in Virginia.