Abstract

THERON-DE BRUIN, Natalie; DREYER, Léanne L.; HUGO-COETZEE, Elizabeth A.  and  ROETS, Francois. Effects of indigenous crop cultivation on mite biodiversity in a biodiversity hotspot. AE [online]. 2025, vol.33, pp.1-11. ISSN 2224-8854.  https://doi.org/10.17159/2254-8854/2025/a21618.

Exotic crop production negatively affects native biodiversity and alters ecosystem functions and services. Cultivation of indigenous crops can mediate some biodiversity impacts, as these are often less intensively managed than exotic crops and they provide familiar niches for native organisms. Protea (Proteaceae), a floricultural crop with high economic value and ecological significance, is harvested within both natural and cultivated systems in South Africa. A multitude of organisms are intimately involved in Protea ecology, but many are also pests and pose significant phytosanitary risks. Here we evaluated the impact of Protea cultivation on the diversity of mites associated with inflorescences, infructescences, and the rhizosphere in the Greater Cape Floristic Region biodiversity hotspot of South Africa. Natural sites harboured higher mite diversity than cultivated sites, although this was only significant for those mites associated with the rhizosphere or when Protea crops were intensively managed. Mite community assemblage composition differed between different management types, localities, and niches. Management actions had little effect on mite assemblage composition in inflorescences and infructescences, likely due to continuous long-distance colonisation from natural areas via pollinators. In contrast, mite assemblages associated with the rhizosphere were highly impacted in all cultivated sites. These results indicate that indigenous crops can sustain substantial above-ground native mite biodiversity, but ecologically important soil assemblages may be severely impacted. Current field-based management strategies are not effective in controlling mite assemblages within Protea inflorescences, posing significant phytosanitary risks.

Keywords : Acari; fynbos; Oribatida; Proctolaelaps vandenbergi; Protea repens.

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