Mesostigmatid mites are characterized by appearing as small tick-like arachnids. They differ from ticks in that the stigmata are located between the third and fourth pairs of legs, and each stigma is associated with an anteriorly directed peritreme. Mesostigmatid mites tend to have long legs and bodies that are covered with small hairs. There are some 19 superfamilies of Mesostigmatid mites (Desch, 1984; Baker et al., 1956). Most of the mites in this group are actualy free-living predators associated with soils and vegetation. Most adult mesostigmatid mites are 0.5 to 0.7 mm long withan oval to oval-oblong body shape. Families of general medical importance include the Macronyssidae which are found mainly on bats, the Dermanyssidae which parasitize birds and mammals, the Laelapidae which includes free-living forms and species parasitic on rodents, and the Halarachnidae which includes the parasitic repiratory mites Pneumonyssussimicola of primates and Pneumonyssoidescaninum of dogs.
There is only a single mesostimatid mite, Dermanyssusgallinae, that is of importance in feline medicine. Many of the parasitic mesotigmatid mites tend to be nest dwelling species, and there are numerous species that are found in rodent nests, such as Ornithonyssusbacoti (the tropical rat mite) and Laelapsnutalli (the domestic rat mite), that one would expect to occasionally be found on cats. However, as of this time the authors are not aware of these mites being reported as causing lesions on feline hosts.
Baker EW, Evans TM, Gould DJ, Hull WB, Keegan HL. 1956. A Manual of Parasitic Mites of Medical or Economic Importance. National Pest Control Association, Inc, NY, NY.
Desch CE. 1984. Biology of biting mites (Mesostigmata). In: Mammalian Diseases and Arachnids, Vol I. Nutting WB (ed). CRC Press, Boca Raton, FL, pp 83-109.