Final remark

For the sake of completeness, it should be pointed out that habitat fragmentation alone is not enough to define a metapopulation. Murphy et al. (1990) request small body size, high rate of population increase, short generation time and high habitat specificity. In order that a plant-pest system can be considered as a metapopulation, Hanski (1997) recommends that host plants are distributed as discrete patches, pest populations within patches have a substantial risk of extinction, empty patches are available for colonization, and pest local populations do not fluctuate synchronously. This topic will not be considered in this course.