ALTERNATIVE POSSIBILITIES OF CABBAGE ROOT FLY CONTROL AFTER THE EFFICIENCY OF CHLORFENVINPHOS AND CARBOFURAN HAS BEGUN TO FAIL IN SOME GROWING AREAS OF THE FEDERAL REPUBLIC OF GERMANY

In some growing areas of the Federal Republic of Germany the control of root flies esp. cabbage root fly /Delia radicum/ and carrot rust fly /Psila rosae/ by applying soil insecticides such as chlorfenvinphos and carbofuran is no : longer possible.
An increased microbiological degradation of the insecticides after using them for many years might be the reason for the failures.

At the moment three alternative possibilities exist to overcome the problem.

1. Protecting the crops with special nets and fleece.
   More and more farmers are using this method although during the summer months they sometimes are getting problems with a minor quality or a higher disease infestation as a consequence of the higher temperatures and humidity under the covering materials.

2. Regular insecticide sprays in short intervals to control the adult flies.

3. Treatments with slow release formulations of synthetic pyrethroids.
   First experiments done with a granular formulation of cypermethrin and deltamethrin showed that one application of 50 mg a.i./m row could be sufficient to control the pest.

International Symposium on Diptera Pests in Vegetable Crops

M. Hommes

https://doi.org/10.17660/ActaHortic.1988.219.7