OVERLAND SPREAD OF THE OAK WILT FUNGUS IN MINNESOTA

摘要: In seven locations involving 158 oaks from 1953-1979, infection occurred only in trees wounded late May or early June. plots established between 1953 and 1980 of over 5,000 wounded, as (one tree 1978) June 1 5. None 322 with wounds painted became infected. Oak can be infected by the oak wilt fungus, Ceratocystis fagacearum, way grafted root systems healthy insects carrying spores. The total number kinds insect vectors is not known, but sap-feeding nitidulid beetles (Col- eoptera:Nitidulidae) are apparently important group Minnesota (3). Research, prin- cipally Iowa, West Virginia Wisconsin that nitidulids transmit fungus when they fly sporulating mats produced on diseased to fresh (1,7,8). This paper presents evidence association wounding Minnesota, based observations made during a period 25 years, ex- periments deliberate 1952, 1953, 1974, 1975, 1978, 1979 1980.