**11. Conclusions**

The spatial and/or temporal separation of host plants is contingent upon the behavior and development of herbivorous insects. Reducing pest populations can be realized by recognizing and identifying their feeding preferences. The more pronounced the feeding preferences, the greater the reduction in the population. Consequently, the damage to host plants grown in mixed sowing systems will be considerably reduced. Monophagous insects are specific in this regard. The slight alteration of a host plant's canopy renders monophagous insects unable to locate an adequate food supply and to establish a suitable breeding base. A significant reduction in the population of oligophagous insects (insects whose host spectrum is in the botanical family) is expected to occur in mixtures of adequately spaced botanical taxa, for example, damage to cereal plants can be reduced by introducing the cereal leaf beetle to cereal–legume mixtures. Numerous empirical data and some theoretical considerations sugges<sup>t</sup> that, in mixed crop systems, the reduction in pest populations is predominantly linked to the availability of food sources and less so to an impact or threat posed by their natural enemies.

**Author Contributions:** Conceptualization, A.W.-P. and D.P.; formal analysis, A.W.-P. and D.P.; investigation, A.W.-P.; resources, D.P.; writing—original draft preparation, A.W.-P.; A.W.-P. and D.P. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.
