SEASONAL ABUNDANCE OF SOIL MITES (ACARINA) IN 2 CONTRASTING ENVIRONMENTS

The soils of a secondary regrowth forest plot and an adjoining cassava plot in southwest Nigeria were investigated over an annual cycle to show the seasonal variations in their mite (Acarina) populations. Data on rainfall, soil moisture content, and soil temperature were simultaneously collected. Microenvironmental differences in the two plots were reported to have influenced the densities, age structure, and fluctation patterns of the mite populations. Like most other arthropods, mostly insects and spiders studied in other tropical environments, the soil mites showed within and between seasonal changes in abundance at both the forest and cassava plots. Two patterns of seasonal fluctuations characterized by a single maximum population density on the one hand and multiple peak populations on the other hand were shown by the mite groups in the forest and cassava plots. Unlike most mite groups whose patterns of fluctuations were similar in the forest and cassava plots, Haplozetes sp., Carabodes sp., Oppia sp., Tectocepheus sp., and Parasitidae were reported to have reacted to the difference in environmental attributes between the forest and the cassava plots by exhibiting different fluctuation patterns between the two plots. The population build-up potential of mites in the cassava plot, especially Haplozetes sp., is discussed.