Cheiroseius aff. trilobus Karg

Rueda-Ramírez, Diana, Varela, Amanda & De Moraes, Gilberto J., 2016, Soil mites of the families Ascidae, Blattisociidae and Melicharidae (Acari: Mesostigmata) from mountainous areas of Colombia, Zootaxa 4127 (3), pp. 493-514 : 507

Cheiroseius aff. trilobus Karg

Cheiroseius (Cheiroseius) trilobus Karg, 1981: 67 .

Cheiroseius (Cheiroseius) trilobus .— Karg, 1998a: 54.

Adult female (one specimen measured).

Gnathosoma. Movable cheliceral digit 45, with two small teeth; fixed digit 47 long, with a deep subapical notch matching apex of movable digit followed by short ridge (ca. 5 µm long) bearing approximately eight fine denticles. Anterior region of epistome with three projections; median projection subtriangular, longest, sharptipped and smooth; lateral projections subapically and externally denticulate.

Dorsal idiosoma. Podonotal and opisthonotal shields fused, 420 long and 245 wide, with 36 pairs of setae. Unsclerotised cuticle with six pairs of setae (r 5, R 1– R 5). Setal measurements: j 1 10, j 2 45, j 3 41, j 4 48, j 5 42, j 6 46, J 1 42, J 2 (longer than the distance to the base of J 3) 43, J 3 (longer than the distance to the base of J 4) 40, J 4 49, J 5 16, z 1 27, z 2 33, z 3 40, z 4 45, z 5 28, z 6 41, Z 1 50, Z 2 46, Z 3 53, Z 4 50, Z 5 52, s 1 21, s 2 31, s 3 45, s 4 45, s 5 47, s 6 47, S 1 47, S 2 45, S 3 47, S 4 50, S 5 51, r 2 20, r 3 20, r 4 36, r 5 25, R 1 19, R 2 22, R 3 25, R 4 25, R 5 27; setae stout and smooth.

Ventral idiosoma. Tritosternum not adequately positioned for measurements. Presternal platelets absent. Sternal shield smooth, 85 long and 68 wide, with three pairs of setae and two pairs of lyrifissures; setae st 1 17, st 2 16, st 3 16, st 4 18. Distances st 1– st 3 70, st 2– st 2 42. Genital shield smooth, 69 long and 59 wide at the widest level; seta st 5 19; distance st 5– st 5 46. One pair of ovoid metapodal plates. Ventrianal shield reticulate, with three pairs of setae (Jv 2, Jv 3 and Zv 2) in addition to circumanal setae, 100 long and 132 wide; anus 13 long. Unsclerotised cuticle around ventrianal shield with five pairs of setae (Jv 1, Jv 4, Jv 5, Zv 1 and Zv 3). Anterior section of endopodal plate fused with sternal shield; sections between coxae II–III and III–IV reduced each to an elongate v-shaped platelets. Exopodal plate consolidated with peritrematic shield; the latter plate wide, fused anteriorly with dorsal shield at level of s 1 and extending posteriorly to level of posterior margin of coxa IV. Peritreme wide, extending anteriorly to base of j 1, without post-stigmatic extension. Setal measurements: Jv 1 17, Jv 2 20, Jv 3 20, Jv 4 21, Jv 5 20, Zv 1 15, Zv 2 15, Zv 3 13, para-anal 19, post-anal 15; all setae stout and smooth.

Legs. Setation: genua I–IV: 13, 10, 8, 9; tibiae I–IV: 13, 10, 9, 10. Tarsi II–IV with a macroseta each (25, 38 and 53, respectively).

Material examined. A female from soil of a fragment of Andean forest–( pH 4.0; organic matter 33%; humidity 46%; soil temperature 9°C) in December, 2010.

Remarks. The specimen examined is most similar to Cheiroseius tetrados Karg, 1998 and Cheiroseius trilobus Karg, 1981 , both of which were described from Ecuador, also without post-stigmatic extension of the peritreme, ventrianal shield with three pairs of setae in addition to circumanal setae and j 1 is much shorter than other dorsal setae. However, both are shorter (dorsal shield 310–340 long and 200 wide in C. tetrados and 340–360 long and 200–250 wide in C. trilobus ). Additionally, in C. tetrados j2 (s 1 in the original description, 30) and Z 5 (40) are shorter, sternal setae (20) are slightly longer, and sternal shield has a longitudinal anteromedian reticulate region (lacking in the specimen examined). Conversely, C. trilobus has S 5 (60) slightly longer than the specimen examined. The identity of this specimen should be confirmed with the collection of additional specimens and an evaluation of the types of those similar species.