Water mites are common and widespread parasites of some aquatic insects in freshwater habitats. This is the first record of acari Arrenurus Dugès, 1834, as a parasite of Odonata in Brazil. Water mites were sampled from Miathyria marcella (Selys, 1857) and Ischnura fluviatilis (Selys, 1876).
dragonfly; parasitism; water mites