Biotechnical methods based strategies

Biotechnical methods include the control of pests with pheromones, the release of sterile insects and the use of insecticides with biotechnical action. Biotechnical insecticides influence the metabolism of insects (e.g. molting inhibitors) resulting in insect death. Biotechnical insecticides primarily do not have a harmful effect on insects, but disrupt processes in their metabolism, resulting in insect death. Because biotechnical insecticides (although considered more environmentally friendly than conventional chemical insecticides) are not all approved for use in organic agriculture, in this chapter we will focus on strategies for applying pheromones and releasing sterile males for pest control.

There are two ways to use pheromones for pest control: Mass trapping and confusion. Both methods are described in Table 3.4. Both methods, as well as the method of releasing sterile insects, are excellent when an area-wide control strategy (hereafter AW) is used to control pests. In contrast to individual control measures that we implement with the goal of immediate damage reduction in a specific area, the long-term goal of the AW program is to reduce pest infestations in a given area below the number that can cause damage. The purpose of this environmentally friendly method is to reduce the population of pests below the decision threshold. The control of a particular pest species is not only done on the crop that suffers economic damage, as in the individual approach (Figure 3.41 A), but on all crops that the pest can feed on (Figure 3.41 B).

Figure 3.41 Graphical representation of the control concept on individual fields (A) and on large areas (B). (After Hendrichs et al., 2007).

3.41.A: Pest population declines below the decision threshold on fields of commercial importance and is not controlled on neglected crops, alternative hosts, backyard hosts, and wild hosts. As a result of control, significant areas remain uncontrolled by the remaining pests, which are then the source of their restored population.

3.41.B: The pest population declines below the decision threshold on all areas, including neglected crops, alternative hosts, backyard hosts, and wild hosts. The result of control is the absence of significant areas to hold the remaining pest individuals that escaped control and would be the source of the restored pest population.

The specificity of this strategy is that it must be organized and implemented by all owners of agricultural land in a given area.