Disease Note

First Report of Cactodera estonica in the United States. R. L. Norgren, Wisconsin Department of Agriculture, Trade and Consumer Protection, Madison 53707. A. M. Goldon, Biosystematics and Beneficial Insects, USDA, Beltsville, MD 20705. Plant Dis. 70:1159. Accepted for publication 3 September 1986. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/PD-70-1159c.

In the fall of 1983, cysts of Cactodera estonica (Kirjanova & Krall, 1963) Krall & Krall, 1978, were recovered from a soil sample collected from a soybean field in Walworth County, Wisconsin. A limited number of cysts were also recovered from the same field in 1984 and 1985, planted to corn and soybean, respectively. Corn, soybean, and several weeds and grasses were determined not to be hosts for the nematode. According to the original description, the lateral field of juveniles has five incisures (1). No cyst nematode is known to have five incisures in the lateral field, however, and examination of type specimens and Wisconsin juveniles revealed only four. According to a Russian report, the only known host plant to date is prostrate knotweed (Polygonum aviculare L.). C. estonica was reported from Estonia in 1963 and since then from Bulgaria, Poland, Sweden, Turkey, and Yugoslavia. This is the first report of the nematode in the Western Hemisphere.