TWO NEW SPECIES OF GYMNODAMAEUS FROM COLORADO (ACARINA: CRYPTOSTIGMATA, GYMNODAMAEIDAE)^ Tyler A. Woolley-and Harold G. Higgins'^ Abstract. — Gymnodamaeus plokosus and G. leurolomasus, n. spp., are de-scribed from soil at an ecological study site near Hayden, Colorado. Their rela-tionship to allied species is discussed. A review of the literature indicates that the first species of Gymnodamaeus were described by Berlese (1910, 1916). Woolley (1972) reviews the literature of known soil mites in the genus Gymnodamaeus and describes a new species, Gymnodamaeus chala-zionus, from the motmtainous areas of northern Colorado. The two new species described below are additions to this genus. The specimens of the first species described below were taken in soil beneath sage and grass along the undisturbed margin of a spoil bank near one of the coal strip-mining sites of the Hayden, Colorado, power plant. Comparisons of these specimens with others in the collections of the writers and with descriptions in the literature indi-cate that the species is new. It is described below and compared with other known species. Those species of Gymnodamaeus from North America with which this new species were compared are G. veriornatus Higgins, 1961, and G. chalazionus Woolley, 1972. The new species is smaller in size than the above species but averages very close to the size of G. gildersleeveae Hammer, 1952, and G. elegantulus Hammer, 1958; it is smaller than G. minor Banks, 1947, slightly larger than G. pearsei Banks, 1947, and much larger than G. quadricaudiculus Jacot, 1937. The details of this size comparison are given below with collection data and measurements of the new species. Gymnodamaeus plokosus, n. sp. (Figs. 1, 2) Diagnosis." — Most easily recognized by the crenulated posterior margin of notogaster with four nubbins, each bearing an ornate, curved hair (Figure 1); differs from G. gildersleeveae Hammer, 1952, in this feature as well as in the marginal placement of the pos-terior notogastral hairs; without reticulate pattern on dorsum of notogaster as in gildersleeveae, but with an arched, transverse bar on prodorsum just anterior to interlamellar hairs which is not present in gildersleeveae. Differs from G. quadricaudiculus Jacot, 1937, in the absence of the dorsal oval sculpturing with rays. The inter-lamellar hairs of the new species are short and most nearly resemble ^Research supported by the Yampa Project; Ecology Consultants, Inc. -Department of Zoology and Entomology, Colorado State University, Fort Collins, Colorado. ^Biology Department, Granger High School, Granger, Utah. 37
BioStor
