Codling moth populations less susceptible to CpGV: What about higher concentrations?

In an organic orchard with a codling moth (CM) population less susceptible to CpGV it was tested, whether an increased dosage of CpGV by factor 10 would result in any increased efficacy. The applications were set in shorter than weekly intervals with 10 ml/ha Madex (low dosage plot) and 100 ml/ha Madex (high dosage plot). The higher dosage showed also a better efficacy, espe-cially on the “active damage” (live larvae). The orchard where the experiments were conducted was known to have a less susceptible CM population (2004) although there were no serious CM problems reported by the farmer despite the CM control was done only with CpGV. It was investigated, whether natural antagonists might have been a reason for the absence of serious problems in this orchard. No signs of a strong presence of other antagonists were found but CM the population was increasing very much in the year the ex-periment was conducted (2005). Thus, probably the reason for the absence of CM problems seems to be just a delayed increase of the CM population after the development of a lower susceptibility of CM against CpGV

Host age selection behaviour of Trichogramma aurosum Sugonjaev & Sorokina (Hymenoptera: Trichogrammatidae)

Host age selection in several German strains of Trichogramma aurosum Sugonjaev & Sorokina was examined in laboratory choice tests under direct observation for 90 min., in order to select candidate strains for attempts at controlling the codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae). Experiments were conducted at room temperature by exposing combinations of two host ages (zero vs. 4 and 1 vs. 5-day old) to a single female wasp. Host age did not appear to affect the wasps parasitization behaviour, although they spent longer time drilling on old eggs (4 and 5 days old) compared with fresh ones (0 and 1 day old). This not necessarily means that they preferred fresh eggs over old ones, since both type of hosts were parasitized in the choice test. Possibly an increased mechanical resistance of the chorion of older eggs was responsible for the prolonged drilling time. Mean drumming time was independent of host age. Mean duration of drilling and drumming was in general longest in the first and last egg attacked by all T. aurosum strains tested and for all host ages. Drilling time consumed more than 80% of the mean handling time of all strains tested for all host ages, followed by resting and walking

Codling moth populations less susceptible to CpGV: What about higher concentrations?

In an organic orchard with a codling moth (CM) population less susceptible to CpGV it was tested, whether an increased dosage of CpGV by factor 10 would result in any increased efficacy. The applications were set in shorter than weekly intervals with 10 ml/ha Madex (low dosage plot) and 100 ml/ha Madex (high dosage plot). The higher dosage showed also a better efficacy, especially on the “active damage” (live larvae). The orchard where the experiments were conducted was known to have a less susceptible CM population (2004) although there were no serious CM problems reported by the farmer despite the CM control was done only with CpGV. It was investigated, whether natural antagonists might have been a reason for the absence of serious problems in this orchard. No signs of a strong presence of other antagonists were found but CM the population was increasing very much in the year the experiment was conducted (2005). Thus, probably the reason for the absence of CM problems seems to be just a delayed increase of the CM population after the development of a lower susceptibility of CM against CpGV

Field tests with Madex Plus against CpGV-resistant codling moth populations in organic orchards in 2006

When resistance to the Mexican isolate of Cydia pomonella Granulovirus (CpGV-M) arose in several organic orchards in Germany in 2004 and 2005, the future of codling moth control became a serious concern of organic fruit growing. In 2006, a new virus isolate from Andermatt Biocontrol AG (Madex Plus) was first tested in two field trials in organic orchards on codling moth populations resistant against the Mexican isolate of CpGV. Madex Plus showed a better efficacy on these populations than Madex 3. However, larval mortality larvae seemed to be somewhat delayed. A very good effect was shown in population control. The number of larvae in corrugated card board belts was significantly reduced after treatment with Madex Plus. In addition to these trials, on-farm trials in all orchards concerned of the CpGV-M resistance were carried out. The results of on-farm trials showed the same tendency: high efficacy in population control against a background of slightly delayed larval death. In 2007, Madex Plus was applied successfully in all organic orchards with CpGV-M-resistant codling moth populations in Germany

Experiences with entomopathogenic nematodes for the control of overwintering codling moth larvae in Germany

Entomopathogenic nematodes were tested for their potential as tool in resistance management of codling moth Cydia pomonella L. in organic fruit growing. In two field tests, the adults emerging from stems treated with nematodes were monitored. In one trial, 90 % of efficacy could be shown. On-farm trials with favourable weather conditions showed an efficacy about 50-60 % on fruit infestation by codling moth in the year following the application. On-farm trials with unfavourable weather conditions showed no results. The favourable weather conditions for the application are discussed with reference to German conditions

Efficacy of Quassia extract on the apple sawfly Hoplocampa testudinea Klug

The efficacy of Quassia extract with a standardized content of Quassin was proved in various field trials in different regions during three years. The amount of Quassin of 6 g/ha/m tree height will be recommended to practice. It is not important to have a contact effect on the eggs. The larvae must feed on the product before they enter the fruit. There is a very good efficacy on primaray infestation. Furthermore, there is even an efficacy on secondary infestation. Thus, even if due to difficult conditions during application or not optimal termination of the treatment the efficacy on the primary infestation is not entirely sufficient, the secondary infestation will be controlled better

Control of the appleseed moth Grapholita lobarzewskii Ragonot in organic fruit growing

Several products were tested for their efficacy in control of the apple seed moth (Grapholita lobarzewskii Ragonot). None of them had a good efficacy. With several treatments with Bacillus thuringiensis an efficacy about 50 % could be achieved. An early treatment before egg-laying seem to improve the results. Quassia extract (9 g Quassin/ha/m tree height) gave efficacy about 50-60 % even if treated only once. NeemAzal gave only moderate efficacy (about 40-50 %). Mating disruption method was effective if the populations were not too high when the treatements were started. With high populations there was no sufficient control in the first year of application

Erste Freilanduntersuchungen zur Wirkung von Madex plus gegen CpGV-resistente Apfelwicklerpopulationen in Öko-Betrieben

In first field tests on codling moth (Cydia pomonella L.) populations proven to be resis-tant against codling moth granulovirus (CpGV) Madex plus, a selectioned CpGV, proved to be rather effective and showed a better efficacy than Madex 3, the standard CpGV-product. However, it is to consider that high amounts of Madex plus were used (50 ml/ha and m tree height each seven sunny days (a rainy day is considered half a sunny day). Moreover, the risk of development of resistance against this new selection is not clear yet. Thus, even if now a new selection of CpGV is available for the first time, the strategy of codling moth control in organic farming must rely on more components than only CpGV and mating disruption in the future

Wirkung von Quassiaextrakt auf die Apfelsägewespe Hoplocampa testudinea Klug

The efficacy of Quassia extract with a standardized content of Quassin was proved in various field trials in different regions during three years. The amount of Quassin of 6 g/ha/m tree height will be recommended to practice. It is not important to have a contact effect on the eggs. The larvae must feed on the product before they enter the fruit. There is a very good efficacy on primaray infestation. Furthermore, there is even an effi-cacy on secondary infestation. Thus, even if due to difficult conditions during application or not optimal ter-mination of the treatment the efficacy on the primary infestation is not entirely sufficient, the secondary in-festation will be controlled better

Zur Regulierung des Kleinen Fruchtwicklers Grapholita lobarzewskii Ragonot

Several products were tested for their efficacy in control of the apple seed moth (Grapholita lobarzewskii Ragonot). None of them had a good efficacy. With several treatments with Bacillus thuringiensis an efficacy about 50 % could be achieved. An early treatment before egg-laying seem to improve the results. Quassia extract (9 g Quassin/ha/m tree height) gave efficacy about 50-60 % even if treated only once. NeemAzal gave only moderate efficacy (about 40-50 %). Mating disruption method was effective if the populations were not too high when the treatements were started. With high populations there was no sufficient control in the first year of application