Dolicheremaeus insolitus, Ermilov, Sergey G. & Anichkin, Alexander E., 2014

Ermilov, Sergey G. & Anichkin, Alexander E., 2014, Taxonomic study of oribatid mites (Acari, Oribatida) of Bi Dup — Nui Ba National Park (southern Vietnam), Zootaxa 3834 (1), pp. 1-86 : 31-32

Dolicheremaeus insolitus sp. nov.

( Figures 19–21 )

With characters of the genus Dolicheremaeus Jacot, 1938 as summarized by Aoki (1967), Balogh & Balogh (1992), Corpuz-Raros (2000).

Diagnosis. Body size 614–863 × 232–365. Body covered with sparse granules. Interlamellar setae longer than rostral and lamellar setae. Bothridial setae with four to six long, strong branches (usually bifurcate distally) and one to four small spines unilaterally. All prodorsal and notogastral condyles present. Notogastral setae long, barbed. Longitudinal short ridge present laterally to setae c and on apodemes IV. Genital plates smooth. Adanal setae ad 3 in preanal position. Lyrifissures iad in paraanal position. Leg setae u thorn-like on all tarsi.

Description. Measurements. Body length 796 (holotype: female), 796–863 (three paratypes: females), 614, 647 (two paratypes: males); body width 315 (holotype), 315–365 (three paratypes: females), 232 (two paratypes: males).

Integument. Body color yellow-brownish. Body covered with granulate cerotegument; granules conical, sparsely located (up to 1). Body surface densely microfoveolate (diameter of foveolae less than 1) and with larger sparse foveolae (their diameter up to 6), but foveolae visible only at high magnification in dissected specimens. Lateral regions of body near pedotecta II tuberculate (diameter of tubercles up to 6).

Prodorsum. Rostrum widely rounded. Rostral and lamellar setae (both 61–82) setiform, densely ciliate unilaterally. Interlamellar setae (77–123) setiform, straight, barbed, inserted dorso-medially to bothridial openings. Bothridial setae (98–123) with weakly developed head, having four to six long, strong branches (usually bifurcate distally) and one to four small spines unilaterally. Exobothridial setae (32–49) setiform, barbed. Medial prodorsal condyles triangular, rounded distally, located separately. Lateral prodorsal condyles elongate, triangular, rounded distally, contacting with lateral notogastral condyles.

Notogaster. Anterior notogastral margin straight, weakly developed. Medial notogastral condyles rectangular, rounded distally, located separately. Lateral notogastral condyles triangular, rounded distally. Ten pairs of long, thickened, barbed notogastral setae: c, la (77–123), h 1, p 1– p 3 (90–118), others (127–143). Longitudinal short ridge (r) present laterally to setae c (sometimes similar ridges also present laterally to la). Lyrifissures im and opisthonotal gland openings located postero-laterally to la.

Gnathosoma. Subcapitulum longer than wide (155–180 × 106–123). Subcapitular setae setiform, smooth; m and h (both 41–49) longer than a (16–24). Adoral setae absent. Palps (86) with setation 0–2–1–3–8(+ω). Solenidion longer than half of palptarsus length, straight, thickened, pressed to the surface of palptarsus, distal part attached to one distal seta. Chelicerae (155–180) with two barbed setae; cha (41–53) longer than chb (20–28). Trägårdh’s organ distinct.

Epimeral and lateral podosomal regions. Apodemes (1, 2, sejugal, 4) well visible (3 absent). Longitudinal short ridge present on each apodeme IV. Epimeral setal formula: 3–1–3–3. Setae 1b, 3b, 3c, 4a (45–53) longer than 4c (36–41), 1c (24–28), 1a, 2a, 3a, 4b (20–24). Setae 1a, 2a, 3a, 4b smooth, others slightly barbed. Setae 3c inserted on pedotecta II; 4c inserted on discidia. Discidia triangular, blunted.

Anogenital region. Four pairs of genital (20–28) and one pair of aggenital (69–77) setae setiform, smooth. Two pairs of anal (69–77) and three pairs of adanal (ad 1, ad 2, 102–110; ad 3, 69–77) setae setiform, barbed. Adanal setae ad 3 in preanal position. Lyrifissures iad short, in paraanal position. Ovipositor elongate (212–245 × 53–61); length of lobes 73–86, length of cylindrical distal part 139–159. Each lobes with four thin, smooth setae: ψ1 ≈ τ1 (45–49) longer than ψ2 ≈ τ a ≈ τ b ≈ τ c (28). Coronal setae absent.

Legs. Monodactylous; claws smooth. Tarsi without teeth. Formulae of leg setation and solenidia: I (1–4–3–4–16) [1–2–2], II (1–4–3–3–15) [1–1–2], III (2–3–1–2–15) [1–1–0], IV (1–2–2–2–12) [0–1–0]; homologies of setae and solenidia indicated in Table 7 . Leg setae u thorn-like (S-type) on all tarsi.

See Table 2 for explanations.

Type material. Collection data for holotype (female): locality 6 (soil); collection data for five paratypes (three females and two males): locality 6 (litter).

Type deposition. The holotype is deposited in the collection of the Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russia; four paratypes are deposited in the collection of the Siberian Zoological Museum, Novosibirsk, Russia; one paratype is deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia.

Etymology. The specific name “ insolitus ” refers to the unusual morphology of bothridial setae.

Remarks. The genus Dolicheremaeus comprises 175 species, which are distributed in the Pantropical and Subtropical regions (data summarized by Subías 2004, updated 2014).

In having the bothridial setae with long branches and presence of all prodorsal and notogastral condyles, Dolicheremaeus insolitus sp. nov. is similar to Dolicheremaeus pectinatus Balogh, 1970 from Sri Lanka. However, it clearly differs from the latter by the morphology of setae u on tarsi (S–S–S–S versus L–S–S–S in D. pectinatus ), bifurcate branches on bothridial setae (versus not furcate in D. pectinatus ) and presence of notogastral ridges laterally to setae c (versus absent in D. pectinatus ).

Figures

FIGURE 19. Dolicheremaeus insolitus sp. nov., adult: A—dorsal view (setae h 2 except alveoli not illustrated); B—ventral view (gnathosoma and legs except trochanters IV not illustrated); C—lateral view of prodorsum and anterior part of notogaster (legs I, II not illustrated). Scale bar (A, B) 200 Μm, scale bar (C) 100 Μm.

FIGURE 20. Dolicheremaeus insolitus sp. nov., adult: A—rostral seta; B—bothridial seta; C—prodorsal and notogastral condyles; D—subcapitulum, left half, ventral view; E—palptarsus; F—chelicera; G—pedotectum II, discidium and epimeral setae 3 c, 4 a, 4 b; H—genital plate, left; I—anal plate, left, and adanal seta ad 1; J—ovipositor. Scale bar (A, B) 20 Μm; scale bar (C, D, F – J) 50 Μm, scale bar (E) 10 Μm.

FIGURE 21. Dolicheremaeus insolitus sp. nov., adult: A—leg I, right, antiaxial view; B—leg IV, right, antiaxial view. Scale bar 50 Μm.

Tables

TABLE 7. Leg setation and solenidia of Dolicheremaeus insolitus sp. nov. (same data for Fissicepheus striganovae sp. nov.)

Leg	Trochanter	Femur	Genu	Tibia	Tarsus
I	v'	d, (l), bv''	(l), v', σ	(l), (v), φ1, φ2	(ft), (tc), (it), (p), (u), (a), s, (pv), e, ω1, ω2
II	v'	d, (l), bv''	(l), v', σ	l', (v), φ	(ft), (tc), (it), (p), (u), (a), s, (pv), ω1, ω2
III	l', v'	d, l', ev'	l', σ	(v), φ	(ft), (tc), (it), (p), (u), (a), s, (pv)
IV	v'	d, ev'	d, l'	(v), φ	ft'', (tc), (p), (u), (a), s, (pv)