Biological control

Biological control

The aphids represent a regular, abundant food resource drawn upon by numerous organisms. Biological control is founded on the use of these organisms, termed as the natural enemies or crop auxiliaries, for cutting down the aphid populations.

These biological control auxiliaries can be deployed in different ways.

Biological control by acclimation

This type of control was the first to be used.

It was implemented to fight against the woolly apple aphid, Eriosoma lanigerum, originally from North America, which appeared in French territory at the end of the XVIIIth Century, with the acclimation in the 1920 of the hymenopteran parasitoid Aphelinus mali. This still helps maintain aphid populations at an acceptable level in many different regions

Inundative biological control

For this method, the auxiliary is bred massively in an insectarium and spread over the crop as a biological treatment.

This approach, however, is still limited to a small number of types of produce, mainly vegetables or ornamental plants, for both technical and economic reasons. One of the difficulties encountered lies in specificity of many of the auxiliaries, but particularly the parasitoids as the predators are generally more polyphagous

Biological control by conservation

This entails managing the environment at the agroecosystem level such as to foster the action of any auxiliaries naturally present. Combined with certain crop maintenance practices, this creates a new approach, which can be called ecological control.