MITES
(Acari)
Ian M. Smith, Evert E. Lindquist
and
Valerie Behan-Pelletier
Biodiversity Assessment and Evaluation
Research Branch, Agriculture Canada
Eastern Cereal and Oilseed Research Centre
K.W. Neatby Building, Central Experimental Farm
Ottawa, Ontario K1A 0C6
INTRODUCTION
Mites (Acari) are the most diverse and abundant arachnids in the Mixedwood Plains Ecozone. In comparison with other arachnids in the Ecozone, including spiders, harvestmen and pseudoscorpions, mites are notable for their small size and often complex life histories. Mites rival insects in diversity of living habits and niches occupied, and are among the dominant arthropods in many soil, freshwater and plant-associated communities. They are permanent residents and integral components of these communities, typically exhibiting specific, obligate interactions with other groups of animals and plants as predators, phytophages, fungivores, saprophages, parasitoids, parasites or commensals. Nearly 10000 species of mites in over 700 genera and 250 families occur in Canada (Lindquist et al. 1979), and about 4000 of these species inhabit the Mixedwood Plains. Soil and litter communities often contain as many as 100 species of mites,(Fig.M-1) including detritivores, fungivores, predators and parasites, contributing substantially to the process of nutrient recycling and the regulation of prey and host populations. Freshwater communities may also include as many as 100 species of water mites (Fig.M-2) whose predatory adults and ectoparasitic larvae exploit various insect hosts and effectively regulate their populations. Communities associated with single host plants may contain up to 25 species of phytophagous, fungivorous and predatory mites. Plant-feeding species directly affect the growth and reproductive capacity of hosts, and may transmit pathogens that further reduce their vitality. Knowledge of the taxonomy, distribution and ecology of mites varies considerably among the various higher taxa. We have reasonably complete information at the species level for only a few of the families represented in the Mixedwood Plains Ecozone.
