Proteremaeus punctulatus Bayartogtokh

Badamdorj, 2003, The soil mite family Eremaeidae (Acari: Oribatida) in Mongolia, with remarks on distribution and diversity of known genera, Journal of Natural History 37, pp. 1571-1610 : 1600-1605

Proteremaeus punctulatus Bayartogtokh

(figures 17–19)

Proteremaeus punctulatus Bayartogtokh, 2000: 150 , figures 5–10.

Diagnosis. Medium in size (512–552 m m); costulae long, relatively thin, widely spaced, nearly parallel or slightly diverging posteriorly; no transverse ridge anterior to costulae; sensilli relatively short, expanded distally into distinctly barbed clavate head; lamellar setae thin, smooth; interlamellar setae barbed; exobothridial setae short, thin, smooth; notogaster relatively wide, slightly narrowed posteriorly; 10 pairs of thin, smooth notogastral setae; postanal process V-shaped; posteromarginal sclerite not evident; genu and tibia III with setae d, coupled with respective solenidia s and Q.

Measurements. Body length 512–552 (536) m m; length of notogaster 344–352 (348) m m; width of notogaster 288–304 (293) m m.

Integument. Body colour yellowish to light yellowish brown. Dorsal and ventral plates and leg segments with relatively thin granular cerotegument. Microtuberculate on interlamellar region, lateral part of costulae and around leg acetabula. Notogaster distinctly punctate-foveate.

Prodorsum. Rostrum smoothly rounded in dorsal view, but very slightly projecting anteroventrally in lateral view. Rostral seta thin, barbed, 52–56 m m long. Lamellar seta smooth, 30-36 m m long. Costula 70–82 m m long, relatively thin, nearly parallel or slightly diverging posteriorly. Transverse ridge anterior to costulae absent. Distance between costulae almost equal to costular length. Interlamellar seta 37–40 m m long, barbed. Setae le and in with small porose rings basally. Exobothridial seta 18–21 m m long, thin, smooth. Sensillus medium long (54–58 m m), expanded distally into distinctly barbed, clavate head (figures 17A, 19A, B).

Notogaster. Oval, about 1.2 times as long as wide. Anterior margin slightly rounded, posterior margin very slightly tapered. Humeral projection well developed. Ten pairs of medium long (36–40 m m), thin, smooth notogastral setae with small porose rings basally; setae of ps series slightly shorter than others. Posteromarginal sclerite not evident (figures 17A, C, D, 19C).

Gnathosoma . Infracapitular mentum wider than long, without noticeable microtubercles. Hypostomal setae a and h medium long, thin, very finely barbed, seta m thicker and almost twice as long as a and h, with more strong barbs (figures 17B, 19D). Chelicera and palp normal for the genus; palpal setation: 0-2-1-3-9(1).

Epimeral region. Sejugal, II and III apodemes well developed. Epimeral setal formula 3-1-3-3, all setae relatively short, smooth. Discidium well developed, subtriangular, distinctly projecting distally (figure 17B).

Ano-genital region. Genital aperture relatively small, about 1.2× as long as wide; anal aperture about 1.3× as long as wide. Ano-genital setae short, smooth; anal and adanal setae with small porose ring basally (figures 17B, C). Postanal process relatively narrow, V-shaped (figures 17C, 19C).

Legs. Measurements of leg segments given in table 5. Setae d present on genu and tibia III coupled with respective solenidia s and Q; setae d absent from genua I, II and tibiae I, II and IV. Femora I–IV and trochanters III and IV with large porose areas. Tarsi and tibiae I–IV with relatively small porose areas. Femora I–IV and trochanter IV with distinct areolae. Formula of leg setation (including famulus) I (1-5-3-4-19), II (1-5-3-4-17), III (2-3-2-4-15); IV (1-2-2-3-12); formula of solenidia: I (1-2-2); II (1-1-2); III (1-1-0); IV (0-1-0). Structure and setation of legs I–IV as shown in figure 18.

Material examined. Fourteen specimens: Mt Ikh Gazryn Chuluu, District Gobi- Ugtaal, Middle Gobi Province, desert steppe ( Caragana microphylla + Stipa glareosa ), organic debris accumulated between rocks, 45°50∞N, 107°10∞E, elevation 1700 m, 15 September 1991; one specimen: Mt Zorgol Khairkhan, District Bayan-Unjuul, Central Province, mountain steppe ( Stipa grandis + Cleistogenes soongorica ), organic layer of soils, 46°40∞N, 105°20∞E, elevation 1740 m, 8 September 1991, Leg. B. Bayartogtokh.

Remarks. The character states of the present material accord well with those of the type specimens, and some supplementary characters are given in this redescription. Adults of this species are very similar to those of P. mongolicus and P. chadaevae ; differences between them are indicated by Bayartogtokh (2000). In addition, two species examined here are different from each other in setation of legs, type of notogastral setae, shape of sensilli and notogaster. Further collecting is needed for comparative studies of immature stages and population variability of these closely related species.

Distribution. Known from dry mountain steppe and semi-desert habitats in central and southern Mongolia.

Key to adults of Mongolian Eremaeidae 1 Lamellar setae inserted on prodorsum, anterolaterad of costulae; five or more pairs of

anal and adanal setae.................. 2 – Lamellar setae inserted on costulae; two pairs of anal and three pairs of adanal setae 7

2 Ventral plate without postanal process; 11 pairs of notogastral setae (figures 1–4)..

................ Eremaeus hepaticus C. L. Koch – Ventral plate with postanal process; 10 pairs of notogastral setae...... 3

3 Interlamellar setae expanded distally; all ventral setae barbed (figure 12).....

............... Eueremaeus crassisetosus sp. nov. – Interlamellar setae attenuate; ventral setae mostly smooth, rarely only anal and adanal

setae barbed.................... 4

4 Tubercles La absent; lamellar costulae long, thick, closely adjacent (figure 13)...

................. Eu. laticostulatus sp. nov. – Tubercles La present; lamellar costulae relatively short, thin, situated far apart.. 5

5 Sensilli clavate, distinctly expanded distally in its barbed portion; interlamellar setae

short, smooth; prodorsum with two pairs of large tubercles, including La (figures 5–7)................. Eu. oblongus (C. L. Koch)

– Sensilli thin, fusiform or very slightly expanded distally in their barbed portion; interlamellar setae long, barbed; prodorsum with only one pair of large tubercles La. 6

6 Sensilli relatively short, fusiform, smooth or with very fine and sparse barbs on their

margin; adanal setae distinctly barbed (figures 9–11).. Eu. tenuisensillatus sp. nov.

– Sensilli relatively long, slightly expanded distally, with strong barbs on their distal half; adanal setae smooth (figure 8)........ Eu. granulatus (Mihelčič)

7 Notogaster distinctly widened posteriorly, its posterior margin conspicuously curved inward............. Proteremaeus chadaevae Golosova – Notogaster distinctly narrowed posteriorly, its posterior margin more or less pointed. 8

8 Notogaster narrow; notogastral setae finely barbed; sensilli weakly clavate; genua I–III

and tibiae II, IV each with seta d, coupled with respective solenidia (figures 14–16)................... P. mongolicus (Golosova)

– Notogaster wide; notogastral setae smooth; sensilli strongly clavate; only genu III and tibia III with seta d; genua I, II and tibiae II, IV without setae d (figures 17–19).................... P. punctulatus Bayartogtokh