Zerconopsis Hull, 1918

Makarova, O. L., Marchenko, I. I. & Lindquist, E. E., 2024, Siberian mites of the genus Zerconopsis Hull, 1918 (Mesostigmata, Ascidae): description of a new species, re-description of Z. michaeli Evans & Hyatt, 1960, and key for species identification, Zootaxa 5496 (1), pp. 1-34 : 3-4

Genus Zerconopsis Hull, 1918

Zerconopsis Hull, 1918, p. 65 . Type species: Gamasus remiger Kramer, 1876 , by original designation.

Diagnosis

Gnathosoma . Anterior margin of gnathotectum with three denticulate projections of similar length, or middle projection longer. Anterior pair of hypostomatic setae (hp 1) and inner palp trochanter seta (v -1) long, attenuated. Corniculi of moderate size and form. Paralabrum usually well developed. Palp without distinct macroseta on tarsus, but often with two apical setae distinct in form—one straight, rigid, with blunted tip, the second seta s-like curved; palptarsal apotele two-tined. Chelicera often slender and long, digits with weak teeth; fixed digit distally usually gutter-like with denticles on both antiaxial and paraxial ventral edges, and with 1–6 denticles (usually as a row) near level of setiform pilus dentilis; antiaxial apical sensorial depression usually present; movable digit with 1–2 teeth besides apical hook. Deutosternal groove wide, with 6–8 (often with seven) rows of numerous denticles. Male movable digit usually unidentate, with spermatodactyl simply tube-like in form, straight or somewhat curved, often with frenulum; free part of spermatodactyl usually twice shorter than digit, projecting anteriorly slightly beyond the apex of the digit.

Idiosoma. Dorsal shield oval or ovoid, of different length/width ratios (lD/wD 1.4–2.0), often fully covering body dorsum, with or without lateral incisions, not arched downwards anteriorly, but vertex bearing setae j 1 and z 1 sometimes pronounced; shield with 1–8 pairs of paddle-shaped setae (always Z 5; often s 4, s 5, Z 3; rarely j 1, j 4, j 6, s 3, z 6, Z 4); most dorsal setae smooth, simple; caudal J 5 often ciliate basally. Podonotal region of shield with 17–22 pairs of setae; paravertical setae z1 usually very small, spine-like, rarely reduced to alveoli. Seta z3 consistently present; s 1 and s 2 inserted on shield margin; marginal r -setae (3–4 pairs) on lateral membrane or on shield margin in female, but usually on edge of dorsal shield in male. Opisthonotal region of shield with posterior margin smooth or slightly or coarsely tuberculated, usually with 14 pairs of setae, S 2 always absent, marginal setae of the R -series (2–5 pairs) off shield in female, but often on shield margin in male. Dorsal gland openings often triplicate. Openings of ventral glands gvb 1 and gvb 2 well developed on exopodal platelets between coxae I–II and II–III, respectively.

Female venter. Presternal platelets well or weakly developed, sometimes absent. Sternal shield fused with endocoxal sclerites between coxae I–II and coxae II–III, its anterior and posterior margins almost straight or concave; shield with three pairs of setae and three pairs of poroids, vestigial gland gv 1, if present, situated on posterior shield margin mediad poroid iv 3. Setae st 4 inserted on soft cuticle (metasternal platelets absent). Epigynal shield slightly broadened posteriorly, with truncate or slightly convex posterior margin; setae st 5 on shield margins or off shield, poroids iv 5 on soft cuticle near posterolateral corners of shield. Epigynal shield flanked by a pair of free narrow endopodal strips along coxae III–IV and usually by three pairs of transverse postgenital platelets (of which two pairs often in a common furrow) posteriorly. Ventrianal shield strongly ornamented over most of surface, with anal opening in medial or posterior position, bearing 1–6 pairs of setae in addition to circumanal setae, always excluding JV 1 and ZV 1; para-anal setae inserted near mid-level of anal opening or at level of its posterior margin; post-anal seta similar to para-anals in length and form or much longer, sometimes paddle-shaped. Soft cuticle flanking ventrianal shield with 1–2 pairs of metapodal platelets and 3–5 pairs of setae. Spermathecal structures not visible.

Male venter. Sternitigenital shield with five pairs of setae (st 1– st 5) and three pairs of lyrifissures (iv1–iv3), fused or free from endopodal strips along coxae III–IV. Ventrianal shield expansive, incorporating sigilla of metapodal platelets of female, bearing 7–9 pairs of opisthogastric setae in addition to circumanal setae, sometimes flanked by ZV4 and R -setae.

Peritrematal structures. Peritreme often with margins crenulate in different degrees, not shortened, extending to dorsal shield vertex where sometimes terminating on ventral surface but their apices not recurved posteroventrally. Peritrematal shield fused with dorsal shield anteriorly at level before seta s 1 in female but fused for a longer interval in male (up to mid-coxa II level); shield free from exopodal platelets between coxae II–III and III–IV, but fused with exopodal strip posteriorly around coxa IV.

Legs. All legs with pretarsi and paired claws (exception Z. apodius Karg, 1969 lacking ambulacrum I), claw I sessile or inserted on pedicel. Leg II in some species stouter than other legs in both sexes. Dorsal setae of legs often strong, inserted on tubercles. On tarsi II–IV, four subapical setae (av -1, pv -1, al -1, pl -1) spine-like or needle-like; dorsal setae ad -2, pd -2 conspicuously elongated and curved ( Figs 19 , 45 ); paradactyli of different lengths; median section of pulvilli rounded. Legs I–IV chaetotaxy moderately reduced: coxae 2–2–2–1; trochanters 6–5–5–5; femora 12–11–6–6; genua 12(11)–10–8–7; tibia 12(11)–9–7–7; leg I genu and tibia each with seta av -2 present or absent; leg III genu with seta pv -1 present. Legs of male commonly without dimorphically modified setae, rarely tarsus II with seta mv dilated basally and attenuate apically.

Description

Figures

FIGURES 18–23. Zerconopsis sibiricus sp. nov., 18, 22. male; 19–21, 23. female. 18. idiosomal venter; 19. tarsus II; 20. palpal tarsus; 21. subcapitulum; 22. cheliceral digits, antiaxial view; 23. leg I (without tarsus). Scale: 18 100 μm; 19, 21, 22 25 μm; 20 10 μm; 23 50 μm.

FIGURES 42–51. Zerconopsis michaeli Evans et Hyatt, 1960, female. 42. idiosomal ventrum; 43. dorsal setae z6, Z3 and nearby gland openings; 44. chelicera, antiaxial view; 45. tarsus II; 46. cheliceral digits, antiaxial view; 47. apical sensillum s on tarsus I; 48. tritosternum; 49–51. variation of sternal shield form. Scale: 42 100 μm; 43 20 μm; 44–46, 48 25 μm; 47 10 μm; 49–51 50 μm.