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Zum Auftreten von Knospen- und Triebminierern an Pappel
Three adult males of Gypsonoma aceriana (Duponchel) were collected in two counties in western Washington State during 1998-99. Although superficially similar to the cottonwood twig borer,G. haimbachiana (Kearfott), of eastern North America,G. aceriana is easily recognized by its distinctive male genitalia.G. aceriana is a notable pest of Populus (Salacaceae) species and hybrids in plantations and nurseries in Europe, where it is known as the poplar shoot borer. Young larvae mine leaves, and older larvae bore into terminal shoots, often causing gall-like swellings. The species may be established in western Washington State, and could become a significant pest in North America.
Gypsonoma aceriana, the poplar shoot-borer, is a common species in poplar plantations and nurseries, where it may cause serious damage by boring into buds and terminal shoots. By screening a number of monounsaturated alcohols and acetates it was found that a mixture of (E)-10-dodecen-1-ol acetate (E10-12:Ac) and (E)-10-dodecen-1-ol (E10-12:OH) in a ratio 7:3 attracts numerous males of G. aceriana. Traps baited with this mixture can be used to monitor flight activity of this moth.
Ein Sexuallockstoff für den Pappeltriebwickler, Gypsonoma aceriana (Duponchel) (Lepidoptera, Tortricidae)
Der Pappeltriebwickler, Gypsonoma aceriana, ist eine der wichtigsten Schadinsekten im Pappelanbau. Bei starkem Befall führt das Einbohren der Larven in den Terminaltrieben zu Kronenmißbildungen und Wachstumsverlusten.
Mit dem Ziel, einen Sexuallockstoff für diese Art zu finden, der sich zur Uberwachung der Art mit Monitorfallen eignet, wurden verschiedene potentielle Lockstoffkomponenten geprüft.
Feldversuche 1982 zeigten das (E)-10-Dodecen-l-ol-acetat attraktiv für G. aceriana und die nahe verwandte Art G. dealbana. Bei Hinzufügung von (E)-10-Dodecen-l-ol erhöhten sich die Fänge von G. aceriana.
Kombinationen dieser zwei Komponenten wurden 1983 wiederum geprüft, und zwar in den Mischungsverhältnissen 10:0, 9:1, 8:2 und 7:3. Es zeigte sich, daß die Beifügung von Alkohol, die Fangrate von G. aceriana stark erhöhte und jene von G. dealbana stark reduzierte. Die besten Fänge von G. aceriana wurden mit einem Acetat-Alkohol-Verhältnis von 7:3 erreicht. Mit dieser Lockstoffmischung kann die Flugaktivität von G. aceriana gut überwacht werden.
Studies on the species composition and structure of parasitoid complex of poplar twig borer,Gypsonoma aceriana (Dup.), on poplar ornamental trees in Sofia and their role in reducing the number of this pest have been conducted during
the period 1990–1997.
Six larval parasitoids—Bracon variator Nees,Orgilus obscurator (Nees),Microdus tumidulus Nees,Apanteles erevanicus Tob. (Braconidae),Pristomerus rufiabdominalis Ucida andPristomerus vulnerator (Panz.) (Ichneumonidae) were identified. Most numerous wereM. tumidulus (41.0%),A. erevanicus (30.6%) andP. rufiabdominalis (19.1%).A. erevanicus andM. tumidulus were dominating during the different years.
The parasitoids ofG. aceriana were solitary, asB. variator is an ektoparasite, and the rest—endoparasites. They attack young host larvae and emerge at the end of the pupal stage. The
life cycle of parasitoids, that have double generation, are well synchronised with the pest development. This was expressed
in the high levels of parasitism, which in some cases reached 61.5%, and as a whole for the different generations they were
5.9–44.4%.A. erevanicus andM. tumidulus were the most important in reducing the number of the pest.