Mites on Curatella americana L. (Dilleniaceae) from Cerrado vegetation remnants in mining site vicinities

摘要

Land use for agricultural and mining activities has increased dramatically in the Cerrado biome, resulting in degradation of natural areas and loss of biodiversity. Among all organisms threatened by these activities, plant-inhabiting mites represent a rather neglected group since fewer studies were conducted with these arthropods in natural vegetation compared to agricultural systems. This situation justifies more efforts to characterize plant mites associated with native flowering plants of the Cerrado. Here we studied plant mite assemblages of the common tree Curatella americana L. (Dilleniaceae) in the Cerrado remnants situated in the vicinities of nickel mining sites in the Brazilian state of Goias. We sampled 33 sites with remnants of natural vegetation belonging to three phytophysiognomies: forest (11 sites), savannah (21 sites) and grassland (1 site). At each site, three to six individual trees were sampled, totalling 132 plants, which harboured 1493 mites belonging to 23 species in 12 families. The most abundant phytophagous and predatory species were Brevipalpus sp. and Pronematus sp., respectively. Mycophagous species and those with unknown feeding habits represented a very small portion of our samples. The Phytoseiidae was the most diverse family with nine species, which suggests the importance of the Cerrado fragments as reservoirs for this family. According to our species accumulation (Mao Tau) and estimated richness (Jackknife 1) curves, more mite species should be present and thus could be collected through an increased sampling effort at the forest and savannah sites. On the other hand, both accumulation and estimated richness curves tended towards an asymptote for the grassland area. Although the studied Cerrado remnants are exposed to nickel mining activity impacts, C. americana still presented a significant species richness of mites, including predatory species with potential benefit to agriculture.