"Cuckoo's eggs" instead of insecticides

With parasitic wasps against pests in fruits and vegetables

Cotton boll worm DBU
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Nobody wants insecticides in food. With the support of the German Federal Environmental Foundation (DBU), it is now the cotton bollworm health and environmentally friendly go to the collar. His caterpillar has over 60 plants such as tomato or corn on her menu. So far, it can only be controlled with high doses of insecticides. The Hessian company AMW Nützlinge / Pfungstadt and the Institute of Biological Crop Protection of the Federal Biological Research Center for Agriculture and Forestry in Darmstadt now want to tackle the cotton bollworm with parasitic wasps.

These lay their own eggs in the pest eggs, from which slip parasitic wasps instead of the pest caterpillars. The DBU supports this "Kuckucksei technique" with around 235, 000 euros.

The cotton bollworm is becoming an ever greater problem for vegetable growers. Because the bristly caterpillar of this moth species, which migrated from Africa and the Mediterranean, does not only like the cotton plants that gave it its name, but also many types of vegetables. "If no suitable biological control method is found against him, the cotton bollworm must be fought with considerable amounts of insecticide, " says Bernd Wührer of the company AMW. "Our goal is therefore to use Trichogramma parasitic wasps against the eggs of the pest. They are well-suited as a natural enemy of cotton bollworm and harmless to humans, plants and other animals. "

The principle is simple: the parasitic wasps lay their own egg in the parasitic egg, from which hatches instead of pest larvae a new generation of parasitic wasps. Through this "cuckoo-egg technique" the infestation is prevented early. For the parasitic wasps there is much to do: a single moth female can lay over a thousand eggs, from which the caterpillars arise.

The project team led by Bernd Wührer wants to work together with greenhouses and plant protection services to determine the optimal time to combat cotton bollworm by parasitic wasps. Also which type of parasitic was most suitable and how many of the animals are best used in which way should be tested. Subsequently, a guideline will be developed, with which the practitioner can carry out the biological control himself. So that the ideal parasitic wasps species is available in sufficient quantity, it is bred by the company AMW. display

"The project helps to continue and strengthen the practiced biological pest management", said DBU Secretary General Dr. med. Fritz Brickwedde. "The cotton bollworm is highly resistant to many pesticides and thus only somewhat chemically combat by frequent use of pesticides. A return to chemical control in greenhouses would put a heavy burden on the environment and increase the presence of pesticide residues in the food chain. "

(DBU, 04.11.2004 - DLO)