Belbodamaeus rarituberculatus, Bayartogtokh, Badamdorj, 2004

Bayartogtokh, Badamdorj, 2004, Oribatid mites of the genera Belba and Belbodamaeus (Acari: Oribatida: Damaeidae) from Eastern Mongolia, Zootaxa 476, pp. 1-11 : 6-9

Belbodamaeus rarituberculatus sp. nov.

( Figs. 3 & 4 )

Diagnosis. Medium in size, with typical characters of Belbodamaeus . Propodolateral apophysis P well developed, subtriangular in shape, projected laterad; prodorsal tubercles Ba, Bp, Da and Dp absent; sensilli very thin, relatively short, slightly flagellate distally; spinae adnatae moderate in size; notogastral setae medium long, darkly pigmented, except very thin and light colored setae of p series, seta p1 conspicuously longer than other setae; ventral tubercles Va and Vp well developed, E2a and E2p absent, tubercle Sa elongate triangular, Sp small, rounded at tip; apodeme apo.2 well developed; epimeral regions III and IV with three and four setae, respectively; tarsus I with 20, tarsus II with 17, tarsi III and IV with 16 and 13 setae, respectively; setae d on genua I–III and tibiae II–IV distinctly longer than their associated solenidia.

Measurements. Body length 360–408 (389) µm; length of notogaster 252–264 (260) µm; width of notogaster 208–232 (223) µm. In total three specimens were measured.

Integument. Body color yellowish brown. Surface of body and leg segments with relatively thin granular cerotegument. Exuvial scalps and adherent debris absent. Leg segments and lateral part of body with fungi micelles.

Prodorsum. Rostrum rounded in dorsal view, but slightly projecting anteroventrally in lateral view. Rostral seta thin, medium in length; lamellar seta slightly longer than seta ro, both setae smooth. Interlamellar seta as long as lamellar seta, thin, smooth, directed posteriorly, flagellate distally. Exobothridial seta thin, twice shorter than lamellar seta. Sensillus (ss) relatively short, thin, setiform and slightly flagellate distally. Bothridium irregular funnel­shaped, with large opening, directed posterolaterad. Prodorsal enanthiophyses B and D absent. Propodolateral apophysis P well developed, subtriangular in shape, distinctly projected laterad. A few microtubercles present on the prodorsum, anteromediad of each bothridium ( Fig. 3 A & C).

Notogaster. Slightly longer than wide, relatively flat in lateral view. Spina adnata (sa) moderate in size, in dorsal aspect directed anterolaterad, but in lateral aspect directed anteroventrad. Notogastral setae medium long, darkly pigmented, except very thin and light colored setae of p series; seta p1 conspicuously longer than other setae. Lyrifissures ia, im, ih and ips, and opisthosomal gland opening conspicuously developed; lyrifissure ip not evident ( Fig. 3 B & C).

Gnathosoma . Infracapitular mentum nearly as long as wide, without noticeable microtubercles. Hypostomal setae h and m of medium length, seta a short, all of them thin, smooth ( Fig. 3 B). Structure of chelicera and palp typical for family.

Epimeral region. Tectum of podocephalic fossa not projected. Apodeme apo.2 well developed. Ventrosejugal tubercles Va and Vp conspicuously developed, Vp bearing epimeral seta 3b; epimeral tubercles E2a and E2p absent. Parastigmatic tubercle Sa long, elongate triangular in shape and sharply projected laterally; tubercle Sp small, rounded at tip. Discidium well developed, projected laterally. Epimeral setal formula 3­1­3­4, all setae thin and smooth ( Fig. 3 B).

Ano­genital region. Structure normal for genus; ano­genital setae medium long, smooth. Adanal lyrifissures situated obliquely, at a level a little anterior to anal setae an2 ( Fig. 3 B).

Legs. Trochanter of leg I with relatively large porose area. Setae d on genua I–III and tibiae II–IV distinctly longer than their associated solenidia. Tarsus I with 20, tarsus II with 17, tarsi III and IV with 16 and 13 setae, respectively. Formula of leg setation (including famulus): I (1­7­4­4­20), II (1­6­4­5­17), III (2­4­3­4­16); IV (1­4­3­4­13); formula of solenidia: I (1­2­2); II (1­1­2); III (1­1­0); IV (0­1­0). Structure and setation of legs I–IV as shown in Fig. 4 .

Material examined. Holotype (female) and two paratypes (females): District Erdenetsagaan, Province Suhbaatar, short grass steppe, soils of 0–5 cm accumulated between rocks, 46°00’02”N, 116°04’25”E, 31 May 2003, Col. B. Bayartogtokh. The holotype and one paratype (alcohol preserved) are deposited in the collection of the Department of Zoology, National University of Mongolia, Ulaanbaatar, Mongolia and one paratype is in the collection of the Zoological Museum of the Moscow State University, Moscow, Russia.

Remarks. The new species, Belbodamaeus rarituberculatus sp. nov. can be readily distinguished form two known species of Belbodamaeus , B. tuberculatus Bulanova­Zachvatkina and B. marginatus Kulijev by the complete absence of prodorsal tubercles B and D, the short, thin and distally slightly flagellate sensilli, the presence of well­developed propodolateral apophysis P, and the absence of the epimeral enantiophysis E2.

Etymology. The specific epithet ” rarituberculatus ” refers to the complete absence of tubercles of the prodorsal and epimeral enantiophyses B, D and E2.

Figures

FIGURE 3. Belbodamaeus rarituberculatus sp. nov. A: Dorsal view; B: Ventral view; C: Lateral view.

FIGURE 4. Belbodamaeus rarituberculatus sp. nov. A: Leg I (right, antiaxial); B: Leg III (right, antiaxial); C: Leg IV (right, antiaxial); D: Leg II (right, antiaxial).