Über das Auftreten von Ophiostoma piceae (Münch) H. et P. Sydow als Begleiter von Thomasiniana spec. bei einer Rindenerkrankung des Weißdorns

Bark cancer and die back of branches was obse·rved on Crataegus in 1955-1957 in Krumbach, Rothaargebirge. lt is suspected with good reason, that this disease is caused by a larva of Cecidomyiidae, which were associated with the bluestaining fungus Ophiostoma piceae (Münch) H. u. P. Sydow under the cancerous parts of the bark. The larva is with great probability Thomasiniana crataegi Barnes. lt is assumed that the occurrence is new for Germany.