Forschungs- und Entwicklungsvorhaben FKZ 01UM022/1 ... - BLE

FVH Az UM022/1 „Biol. Bekämpfung Apfelwickler“ Hopfenbauverein Immenstaad Abschlußbericht 53
If the population is high for the following year, there can be easily further problems. The
concept “keep down the populations” has also great advantages regarding the risk
management.
The treatments of the commercial orchards were done always mainly against the frist
generation of Codling moth. During this period, the application of CpGV can be combined
with the fungicide treatments which are often necessary. In late summer, when fungicide
treatments are usually not that frequent, CpGV treatments were also rare due to the effect of
the mating disruption.
During the time of the investigation (4 years) the Codling moth population of the area
covered by the project did not show any sign of a reduction of the susceptibility to CpGV.
This reduction, however, could be shown in other populations originating from organic
orchards in this and other regions where problems with codling moth arose in 2003.
Nearly all the populations sampled in organic orchards with codling moth problems arising in
2003, 2004 and 2005 proved to be 1,000-fold less susceptible to CpGV than other
populations. Most organic orchards in Germany (about 500-600) do not show any codling
moth problems until now. Still it is not known if resistant codling moth populations have
always existed in nature and have been selected now or if there is another background of the
resistance building.
Nevertheless, actually the strategy developed in this project must be discussed also under
the aspect of the risk of resistance building.
Another problem was Grapholita lobarzewskii. It was present in all orchards at the end of the
project, However, damage was caused only in few cases. The monitoring and prognosis with
pheromone traps proved to be difficult due to behaviour of this species that occurs on small
spots and does not disperse in the whole orchard. A solution for this problem could be the
application of mating disruption for this species. Actually, this pheromone is not registered in
Germany.
In the recent situation, it seems best to introduce also one treatment with a synthetic
pesticide to control Grapholita lobarzewskii in June into the basis strategy, and to establish a
certain resistance management for CpGV.
The reduction of Adoxophyes orana in the area covered must not be necessarily due to the
strategy performed with area-wide granulovirus treatments. A similar reduction could be
observed in the whole region. A very high parasitization of the larvae of the summer
generation in the second year was obvious. Due to the “collapse” of the population this could
not be observed further. The occurrence of Spilonota ocellana, Noctuid larvae and
Operophtera brumata must be considered planning a strategy based on granulovirus
treatment against Adoxophyes orana.
7 Zitierte Literatur
Andermatt, M. (1989): Die mikrobiologische Bekaempfung des Schalenwickler Adoxophyes orana F.v.R.
mittels Granuloseviren. Diss. ETH Zuerich.
Bathon, H., 1981: Zur Zucht des Apfelwicklers, Laspeyresia pomonella (L.) (Lep., Tortricidae), auf
einem künstlichen Nährmedium. Mitt. dtsch. Ges. allg. angew. Ent. 2, 136-140.
Charmillot, J.P. & Pasquer, P.J. (1998): Le virus de la granulose du carpocapse Cydia pomonella: 3.
Essa pratique de longe durée. Revue Suisse Vitic. Arboric. Hortic. 30 (3): 185-187.