EN
The fauna of ptyctimous mites of Costa Rica has been described and analysed. At nearly 200 localities in all provinces of Costa Rica, 76 species of ptyctimous mites (6 Mesoplophoridae, 31 Euphthiracaroidea, 39 Phthiracaroidea) represented by over 3300 specimens have been found. Over 40% of species are new to science. Descriptions of 32 new species have been given: Mesoplophora (Parplophora) bacula sp. nov., Oribotritia alajuela sp. nov., O. allocota sp. nov., O. brevisetosa sp. nov., O. laselve sp. nov., O. nasalis sp. nov., O. partita sp. nov., Mesotritia semota sp. nov., Euphthiracarus evexus sp. nov., E. pedanos sp. nov., E. serangos sp. nov., E. tesselatus sp. nov., E. tumidus sp. nov., Rhysotritia meristos sp. nov., FL parallelos sp. nov., Phthiracarus totus sp. nov., Plonaphacarus baculus sp. nov., Austrophthiracarus nexilis sp. nov., A. retrorsus sp. nov., Austrophthiracarus zeuktos sp. nov., Arphthicarus allocotos sp. nov., A. iubatus sp. nov., A. pararidiculus sp. nov., A. parasaucius sp. nov., A. pervalidus sp. nov., Protophthiracarus clandestinus sp. nov., P. heteropitosus sp. nov., P. heterosetosus sp. no Notophthiracarus pedanos sp. nov., Atropacarus (Hoplophorella) frondeus sp. nov., Atropacarus (Atropacarus) antrosus sp. nov., A. (A) folious sp. nov. The identification keys of the families, genera and species with figures of the species are presented. On the basis of the data collected, it is difficult to distinguish between the fauna of ptyctimous mites from the western and eastern coast, or north-western and south-eastern parts of the country. The most abundant species, whose representatives make over 30% of all ptyctimous mite specimens found in all samples, is pantropical Plonaphacarus kugohi occurring mainly in the rain forest La Selva. The fauna of ptyctimous mites of Costa Rica is to a large extent harmonic. Euphthiracaroidea are represented by all main genera, whereas from among Phthiracaroidea the genera Hoplophthiracarus and Steganacarus have not been represented, and the gondwanian Notophthiracarus was represented by only one species. The fauna of ptyctimous mites in Costa Rica is typically Neotropical. Over 21% species are widespread: semicosmopolitan and pantropical, the others are neotropical. From among the latter only 18% are widespread in the Neotropical region, 35% are bound with Mexican subregion, and nearly half (46%) are restricted to Costa Rica, including 17% of endemic species. The fauna of ptyctimous mites of the region is weakly related to the fauna of Nearctic region, only a few of the species reach the south states of the USA.