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Beneficials can prevent or reduce outbreaks of pest species. To strengthen the populations of beneficials, their food sources must be improved in cultivated areas. The effects of habitat management for augmenting beneficial population on parasitism and predation rates of three lepidopteran pest species were investigated on two organic fields in Alten (Switzerland). The aim was to improve pest regulation through wild flower strips along fields and by planting Centaurea cyanus as companion plant within the crop. Strips of Centaurea cyanus and Fagopyrum esculentum increased parasitsm on the lepidopteran pests. C. cyanus planted as companion plant furthermore increased predation on the eggs and parasitism of the larvae of Mamestra brassicae. Several technical and methodological aspects still need to be improved before the approach is ready for practical use.

Pollen beetles (Meligethes sp.) are important pests in oilseed rape (Brassica napus). In our study we wanted to determine which landscape structures have an influence on pollen beetle population in early spring. The dynamics of pollen beetle population and the damages on rape were studied on field scale level with 100 sampling points per field and on landscape scale level with 18 organic oilseed rape fields which differed by the complexity of the surrounding landscapes. The number of pollen beetle was strongly correlated with the distance to a forest. At the beginning of the flight period more pollen beetles were found close to the forest, later they migrated to the rest of the field. In addition, agricultural practices appeared to be determinant for pest control. Less pollen beetles per plant were found in fields with a higher density of rape plants.

Although the European organic agriculture movement was founded by Rudolf Steiner and Hans Mueller in the years between 1924 and 1940, it was not until the 1980s that pest management researchers began to develop strategies to control pests in organic systems. Today, insect pest management in organic agriculture involves the adoption of scientificallybased and ecologically sound strategies as specified by international and national organic production standards. These include a ban on synthetic insecticides and, more recently, on genetically modified organisms (GMOs). The first phase of an insect pest management program for organic systems is the adoption of cultural practices including diverse crop rotation, enhancement of soil quality by incorporation of specific cover crops and/or the addition of soil amendments, and choice of resistant varieties that help to prevent pest outbreaks. In the second phase, habitat management (e.g. incorporation of hedgerows and wild flower strips) is implemented to encourage populations of pest antagonists. Third and fourth phases of the program include deployment of direct measures such as biocontrol agents and approved insecticides. However, the strategies for pest prevention implemented in the first two phases often obviate the need for direct control measures. Approaches to pest management in organic systems differ from those in conventional agriculture conceptually in that indirect or preventative measures form the foundation of the system, while direct or reactive control methods are rare and must comply with organic production standards. The range of European research activities that support these concepts is illustrated by a case study of rosy apple aphid (Dysaphis plantaginea) control in organic apple production in Switzerland.