Original paper

Zum Vorkommen potentieller Vektoren der Eichenwelke in Süd-Niedersachsen (Mitteleuropa)

Doganlar, Miktat; Schopf, Reinhard; Bombosch, Siegfried

Entomologia Generalis Volume 10 Number 1 (1984), p. 35 - 46

49 references

published: Nov 1, 1984

DOI: 10.1127/entom.gen/10/1984/35

BibTeX file

ArtNo. ESP146001001004, Price: 13.20 €

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Kurzfassung

Ein durch Insekten verbreiteter Pilz, Ceratocystis fagacearum (Bretz) Hund, verursacht in den Vereinigten Staaten die Welke-Krankheit der Eichen [Henry et al 1944, Gibbs & French 1980]. C. fagacearum dringt über Wurzel-Verwachsungen oder Xylem-Verletzungen in den Baum ein und besiedelt die äußeren, Wasser führenden Leitungsbahnen, über die auch seine Konidiosporen verbreitet werden [Young 1949]. Die basale Ausbreitung des Pilzes in der Wirtspflanze erfolgt durch vegetative Hyphen im Phloem [Kuntz et al 1952]. Mycelgeflechte und Sporenlager werden ferner zwischen der Rinde und dem Holzkörper angelegt, wobei erstere häufig unter dem Druck der reifenden Sporenpolster reißt [Curl et all 1952, Kuntz et al 1952]. Die Eichen zeigen im fortgeschrittenen Erkrankungszustand häufig typische Welkesymptome und sterben in der Folgezeit im allgemeinen ab.

Abstract

In North America the oak wilt disease is caused by Ceratocystis fagacearum (Bretz) Hund, a fungus which is transmitted by insects. In the S' part of Lower Saxony (FRG) the occurrence and abundance of those insects were investigated which could probably transmit C. fagacearum if it spreads to Europe. The study includes oak wound-associated insects which visit existing wounds or which are able to injure healthy oak trees by themselves. The first group comprises representatives of the ordines Heteroptera, Homoptera, Hymenoptera, Psocoptera Collembola, Coleoptera and Diptera, the last 3 named ordines being numerically predominant. The Diptera included species from 10 familiae, Sciaridae, Mycetophilidae, Lauxaniidae, Muscidae, Dolichopodidae, Phoridae, Empididae, Rhagionidae, Cecidomyiidae, and Drosophilidae. With the beetles, species from Staphylinidae (7), Nitidulidae (8), Rhizophagidae (3), Lathrididae (1) were identified. The results show that in mixed oak stands in Lower Saxony, species of those familiae and genera are present which are known to transmit C. fagacearum in North America. The European bark beetle Scolytus intricatus Ratzeburg 1837 is one of the most important European insects being able to attack primarily oak. In Lower Saxony S. intricatus has been present during the last few years in relatively high population densities.

Keywords

Ceratocystis fagacearumSouthern Lower Saxony