Biological pest management on greenhouse roses using open rearing units of Aphidoletes aphidimyza (Rond.) on cereal aphids as a key control strategy.

摘要

In practical application open rearing units of A. aphidimyza on cereal aphids proved to be able to function as a most effective key control strategy in the framework of biological pest management in greenhouses. Populations of aphids on roses but also that of spider mites were controlled at low density levels. It also became evident that the efficiency of A. aphidimyza in the open rearing units was enhanced to a higher degree by other natural enemies of aphids and spider mites, such as aphid parasitoids, syrphids, lacewings, ladybirds and also the acariphagous gallmidge Feltiella acarisuga, which immigrated into the greenhouses due to the permanent presence of cereal aphids. In the second year of the experiments, chemical control against aphids and spider mites was in most cases not necessary. The biological control against thrips was less successful, especially if the western flower thrips, Frankliniella occidentalis, was involved. Failures in the biological control against thrips also existed during the period of cereal harvest, when other thrips immigrated into the greenhouses in high numbers. Damages caused by thrips could only be reduced by integrated control, using both natural enemies and selective chemicals. In greenhouses with biological pest management, some secondary pests e.g. whiteflies, cicadas and also butterflies were detected in higher numbers than in greenhouses without biological control.