Abstract:
Some plant species possess structures known as leaf domatia, which house mites.
The association between domatia-bearing plants and mites has been proposed to be mutualistic,
and has been found to be important in species of economic value, such as grapes, cotton, avocado and
coffee. This is because leaf domatia affect the distribution, diversity and abundance of predatory and
mycophagous mites found on the leaf surface. As a result, plants are thought to benefit from increased
defence against pathogens and small arthropod herbivores. This study assesses the relative diversity
and composition of mites on an economically important plant host (Coffea aribica) in comparison to
mites found in a neighbouring indigenous forest in South Africa. Our results showed that the coffee
plantations were associated with only predatory mites, some of which are indigenous to South Africa.
This indicates that coffee plantations are able to be successfully colonised by indigenous beneficial
mites. We also found an “edge effect”, in that coffee trees at the edge of the plantation hosted fewer
mite species. These results are a snap-shot from a single sampling period. Nonetheless, they highlight
the potential importance of this mutualism in commercial crop species and the possible role of faunal
exchanges between indigenous and exotic crop species. This study expands our understanding of the
mite–plant mutualism in Southern Africa, a region where acarological studies are sparse.
