Uroseius sorrentinus ( Lombardini, 1952 )

Moraza, María L., 2019, New data on the genus Uroseius Berlese (Acari: Mesostigmata: Uropodina Trachytidae) with a redescription of U. sorrentinus (Lombardini, 1952), Zootaxa 4717 (1), pp. 7-29 : 11-26

Uroseius sorrentinus ( Lombardini, 1952)

Polyaspis sorrentinus Lombardi, 1952 : Redia XXVII, 190 by present designation

Pholeogynium sorrentinus ( Johnston, 1961) : Acarologia III (4), 532

Diagnosis. Adult female: Idiosoma widened, rounded, with prominent vertex knobbled anteriorly, strongly tuberculate, one pair of conspicuous glands; dorsal shield not covering vertical region, with approximately 26 pairs of short, brush-like setae, one pair of long setae on pigmented soft cuticle at posterior margin of dorsal shield; soft light cuticle with feathered setae, distally stoutest, short, medium and long setae in three irregular rows on platelets, each bearing one or two gland pores; approximately 24 pairs of marginal setae on soft marginal band. Genital shield with spine-like anterior process, anterior half of shield covered by soft sternal cuticle; 15–20 pairs of feathered ventral setae, heterogeneous in length.

Adult male. Medial dorsal shield with 30–31 pairs of setae, posterior setae longer; genital opening between coxae IV; opisthogastric region with axillar cuticle transparent. Leg II with seta av modified as spurs in femur, genu and tibia; tarsus II with two enlarged, spine-like setae. Both sexes, leg I with rod-like distal projection.

Deutonymph. Idiosoma fusiform, dorsal shield does not cover vertex, with conspicuous ornamentation and approximately 40 pairs of setae; dorsolateral region of soft cuticle striate and light, with a row of approximately 24 pairs of short, brush-like setae; approximately 24 pairs of marginal setae on a poorly sclerotized band; all dorsal setae on soft cuticle on small tuberculate platelets. Presternal transverse sclerite present; sternal shield entire with three pairs of conspicuous sternal gland openings; peritrematal, metapodal and ventrianal shields ornate; ventrianal shield with 8–10 pairs of setae, 7–8 additional pairs on soft opisthogastric cuticle. Gnathosoma with setae h2 thin, shorter than distance between bases of h1 and h2 and shorter than h1; h3 almost as long as h1 with h4 shortest and thickest setae; base of tritosternum with two triangular projections at lateral corners with dentate lateral margin.

Description of the Protonymph. Idiosoma ovoid in shape, 619–620 long, 425 wide at middle widest level (n=3).

Idiosomatic dorsum ( Fig. 3a ). Podonotal shield 289 long, 236 wide at widest level, posterior region acuminate with rounded posterior end, strongly ornamented with numerous large groups of luminous pits grouped in rosettes; shield with five pairs of setae short (3–5 long) and pectinate (j3–j6, z5, J1), and three pairs of glands (gd5, gdm2, gdm3*). One pair of mesonotal shields 75 long, 68–70 wide; shields ornamented, with one pair of poroids (idm1) and punctiform gd6; pygidial shield ornate with pits arranged in round areas, nude, with anterior margin lobed, narrow (27–28 long at midpoint, 44–46 at lateral region) and long (147–149). Dorsal soft cuticle striate with round tubercles forming a polygonal network, with 24 pairs of short, feathered setae inserted on round small platelets, most of them with one or two pores: setae j1 longest (36–38), on acuminate anterior margin; other dorsal setae homogeneous in length (14–20): podonotal setae j2, j3, z2, z4, z5, s4–s6, r2, r3, r5; opisthonotal setae J2–J5 shortest, Z1–Z5, S 2–S5, R1; platelets of dorsal setae j2, j3, s4, s5 with gland openings (gd1, gdm1*, gdl1*, gdl2*,); seven more pairs of dorsal glands (gdm4 *, gd4, gd7, gd8, gd9, gdl3*, gdl4*), and eight pairs of discernible poroids, two pairs podonotal (id2, id4) and six pairs opisthonotal (idm3, idl1–idl5).

Idiosomatic venter ( Fig. 3b ). Narrow, lobed transversal presternal sclerite present (58 wide). Sternal shield 139 long, 78 wide at level of setae st2; anterior margin rounded, posterior margin narrow and rounded; shield covered with small circular pits; shield with sternal setae st1–st3 smooth and thin, similar in length (13–15), poroid iv1 at lateral margin of shield behind st1 and a pair of glandular organs (gst2 *) at level of st2; setae st5 absent, iv5 present between coxae IV. Ornate sclerotized exopodal strips around coxae II and III and well-developed parapodal ornate sclerite around coxae IV.

Free peritrematal shields similarly ornate, 125 long, extending from medial region of coxae II to posterior region of coxae III, with posterior rounded margin; shield with one gland (gp2); one pair of glands (gp0) between coxae I and II, gp3 at level of coxae III, and poroids ip2 and ip3 on soft cuticle; peritremes 111 long slightly curved, not extending posteriorly to stigmata. Small metapodal ornate shields, 86 long, 27–28 wide, behind coxae IV.

Wide anal shield rectangular in shape with rounded lateral margins; shield 83 long, 150 wide; shield with same ornamentation as dorsal shield; one pair of short pubescent paranal setae (8–10), one pubescent adanal seta, and glands gv3 at lateral margins; cribum approximately 11 long, 147 wide. Opisthogastric soft cuticle with four pairs of pectinate setae, JV1 (13–14), JV2, JV5, ZV2 (14–17), three pairs of gland openings (gv2, gv4*, gv5*), and five pairs of poroids (ivo1–ivo4, ivp).

Gnathosoma . Tritosternum with a wide base (25 long, 33–34 wide), anterior border with a pair of anterior triangular projections with lateral margin dentate; hypostomal laciniae with four setulose branches approximately 35 in length. Gnathotectum as in adult instar. Deutosternum with two transverse rows of denticles; hypostomal setae h1 as long as h3, h2, shorter than distance h1–h2, and palpcoxal seta h4 thicker and shorter than h3. Corniculi horn-like, with acute tip, well-separated from base to apex; long, blunt-tipped salivary styli. Chelicera 136 long, movable digit 25 in length, with one tooth; fixed digit similar to that of the female, with conspicuous dorsoapical globular sensilla. Palpi 102–106 in length, with normal setation as described for Uropodina .

Legs. Leg lengths (excluding pretarsi): I (333), II (325), III (281), IV (345). Leg I, tarsus about 2.4 times longer than tibia. Complement of setae on leg segments for coxae I-II-III-IV (2-2-2-1); trochanter I-II-III-IV (4-4-4-3); femora I-II-III-IV (9-8-5-5); for genua I-II-III-IV: (1-2/1, 2/1-1) (1-2/0, 2/0-1) (1-2/0, 2/0-1) (1-2/1, 2/1-1); for tibiae: (1-1/1, 2/1-1) (1-1/1, 2/1-1) (1-1/1, 2/1-1) (1-2/1, 2/1-1). Coxae I–IV with margins strongly serrate. Tarsi II–IV with hyaline, lobulated ventroapical process and paradactyli with medial lobe of pulvilli acuminate; setae ad-1, pd1 longer than pretarsus to base of claws; dorso-apical gland present.

Description of the Deutonymph. Idiosoma fusiform in shape, 753 long, 467 at middle widest level.

Idiosomatic dorsum ( Fig. 5 ). Vertical region pentagonal in shape, with setae j1, j2, z1, several supplementary setae x, and large glandular opening (gd1); longest setae j1 22–25 long, and z1 14 long inserted on ventral side of vertex. Central dorsal shield 700 long, 378 wide, not covering vertical region, with irregular lateral margin and completely covered with numerous large groups of luminous pits grouped in rosettes, except in medial region between central setae (from setae j4 to J1) where isolated pits are rounded. Dorsal shield bears approximately 38 pairs of short homogeneous setae (11–13 long), with tips spiculate ( Fig. 6 ); podonotal region of shield with variable number of uneven seta jx and at least four pairs of x; opisthonotal region with complete dotation of series J, Z, S, R6 and at least one pair of x. Dorsal shield with at least 11 pairs of discernible glands and four pairs of discernible lyrifissures (id2, id6, idm1, idm3, idl5).

Soft cuticle around central dorsal shield with approximately 23 pairs of short setae, at least seven to eight pairs of them on platelets bearing glandular openings: podonotal setae r1–r6 and plicate setae rx in a podonotal row, opisthonotal setae R1–R6 and at least eight pairs of x in two irregular rows; at least five pairs of discernible, isolate lyrifissures ( Fig. 5 ) and three pairs of punctiform glands; about 30 more pairs of marginal setae on poorly sclerotized marginal band; mostly lateral and marginal setae 8–12 long. Glands and lyrifissures absent on marginal bands.

Idiosomal venter ( Fig. 8 ). Transversal presternal sclerite present, with lobed anterior margin and finely punctate, 8–9 long at medial point and 62 wide. Sternal shield 203 long, 86 wide at level of setae st2; anterior margin rounded and posterior rounded and slightly concave; shield completely covered with small circular pits; shield with sternal setae st1–st3 thin and smooth, similar in length (11–13 long), poroid iv1 at lateral margin of shield behind st1 and a punctiform pair of organs at posterior region of shield; setae st4 off shield, similar to other sternal setae; three conspicuous glandular organs in soft cuticle lateral to shield (gst1*–gst3*); poroids iv5 and setae st5 13 long at level of coxae IV, slightly shorter than sternal setae. Endopodal strips of well-sclerotized ornamented cuticle around coxae II and III, fused to well-developed parapodal sclerites around coxa IV; ornate exopodal sclerites around II and III.

Free peritrematal shields similarly ornate, 306 long, extending to posterior region of coxae III, with posterior lobed margin to vertical region; shield with two glands (gp1, gp2) and poroid ip2 highly distinctive; peritremes 217 long with slightly curved distal region and straight posterior region, with a short extension posterior to stigmata ( Fig. 10 ); exopodal region, behind posterior margin of peritrematal shield, with two pairs of platelets bearing glandular openings (gp3, gp4*). Large ornate metapodal shields, 194 long 128 wide at level of coxae IV, shields with one pair of large platelets with two glandular openings (gv5 *) ( Fig. 11 ), sometimes one pair of opisthogastric setae, and one pair of lyrifissures (ivo2); lateral margin of metapodal shields with a well-sclerotized frame.

Wide ventrianal shield pentagonal in shape, 275 long, 233 at widest anterior region, 83 at narrowest posterior region, anterior to anal opening; shield with rounded anterior border and excavated posterior section, anterior to anal region, irregularly eroded; shield with same ornamentation as dorsal shield. Shield with 8–10 pairs of thin and smooth setae, 6–8 long (setae JV2, JV3, JV4, ZV1, ZV2 and 3–5 Vx) and one pair of poroids ivo1; opisthogastric soft tegument with seven pairs of thin setae, including pair JV5. Two pairs of smooth adanal setae on small platelets, anterior pair 12 long and posterior pair 17 long; anterior anal platelet with one pair of pore-like structures (gva*) and posterior with cribrum ( Fig. 12 ). Opisthogastric soft cuticle with two pairs of glandular organs, gland openings gv2 on ornate ovoid platelets with two openings ( Fig. 11 ) and glands gv4 * between ventrianal and metapodal shields.

Gnathosoma . Tritosternum with a wide base (39 wide, 33–34 long), anterior border with a pair of anterior triangular lateral projection with lateral margin dentate; laciniae with base 34 long with four setulose branches approximately 35 long ( Fig. 9 ). Gnathotectum with long, medial prong-bearing lateral spines. Deutosternum with three transverse rows of few denticles (6, 5, 7 teeth, respectively; hypostomal setae h1 (50–56 long) slightly longer than h3 (34–38), h2 24 long, shorter than distance to base of h1, and palpcoxal seta h4 clearly thicker and shortest (19–24) ( Fig. 14 ); hypostomal laciniae short and pubescent. Corniculi normally horn-like, wide at base, with acute tip, 75–80 long, well-separated from base to apex ( Fig. 14 ); long, blunt-tipped salivary styli ( Fig. 14 ); paralabrum long, with long barbs at internal margin ( Fig. 15 ). Chelicera 158–167 long, movable digit 25–28 long, with one tooth; fixed digit similar to that of female, with dorsal apical tubercle bearing a globular sensillum ( Fig. 7 ). Palpi 122–128 long, with normal setation as described for genus; palptrochanter with two short spines at anterior lateral margin, with v1 acute and 61 long and v2 short (7–11); palpfemur seta al spiniform.

Legs. ( Figs 20–24 ). Leg lengths (excluding pretarsi): I (424), II (453), III (412), IV (461). Leg I pretarsus absent, tarsus 128 long, about 3 times longer than tibia (55–57). Complement of setae on leg segments for femora I-II-III–IV (9-8-6-7); for genua: (1-2/1, 2/1-1) (1-2/1, 2/1-1) (1-2/0, 2/1-1) (1-2/1, 2/0-1); for tibiae: (1-1/1, 2/1-1) (1-1/1, 2/1-1) (1-1/1, 2/1-1) (1-1/1, 2/1-1). Tibia I with al-1 slightly modified as a thick, spine-like seta ( Fig. 20 ); genu IV without pl-1. Legs I–IV, dorsal setae of genua and tibia with lateral pectinate lamellae ( Fig. 24 ); ventral setae smooth and lateral setae smooth or poorly pectinate. Coxae I with glandular field with numerous gland openings ( Fig. 18 ); coxae II–IV with a few or no gland pores; coxal setae smooth. Tarsi II–IV ( Fig. 48 ) with hyaline ventroapical pretarsal process, with lobate pulvilli, and setae ad-1, pd-1 (33-33-47) longer than pretarsus including claws; dorso apical gland present; tarsal dorsal setae pectinate, lateral and ventral setae somewhat spine-like and of similar length; setae av-1, pv-1 slightly thicker and longer; telotarsal dorsal lyrifissure close to basal peripodomeric tarsal fissure ( Fig. 48 ). Ventrolateral anterior and posterior margin of leg segment strongly serrated.

Description of adult female

Idiosomatic dorsum. ( Fig. 25 ). Idiosoma rounded with prominent vertex, 839–1064 long, 622–794 wide. Except for dorsal and anal shields and sterni-genital region, surrounding dorsal and ventral integument flexible although darkly pigmented and densely punctate with large shallow pits in peritrematal and metapodal regions.

Vertex lobed with lateral and ventral round tubercles. Vertical pair j1 55–68 long, thick and densely pubescent; dorsally three pairs of shorter setae and one pair of large glands (gd1).

Dorsal shield finely punctate, 556–570 long, 381–410 at widest level, with irregular borders and posteriorly truncate with two lateral depressions at lateral posterior edges; most of caudal region darkly pigmented with thicker elastic cuticle bearing a pair of long setae noted as J5 on platelets. Shield has approximately 26 pairs of short pubescent setae (8–12) (j3–j6, z2–z6, s1–s6, J1–J4, Z1–Z3, and asymmetrically two uneven setae jx, and four pairs of “x” (copies of setae z6, s4–s6?)); each seta on dorsal shield with one or two gland pores at base; only one pair of lyrifissures discernible (idm3).

Surrounding soft cuticle bearing approximately 58 pairs of setae heterogeneous in length, short 11–12, medium 27–44 and 61–73 longest; short setae with pectinate tips, medium and longest setae stoutest distally, with wide head spiculate ( Fig. 26 ). This complement of setae includes setae s3, r1–r6, Z4, Z5, S1–S5, R1–R6, and 37 pairs of complementary setae x. Setae s3, Z5, Z4, S4 flanking shield laterally; other dorsal setae in three irregular rows: first row with 17 pairs of setae (r1–r6, S1–S5, R6, and five pairs x), three pairs being longer; second row with 14 pairs of medium to long setae (five pairs of longest dorsal setae); third row is most marginal consisting of approximately 19 pairs of short to medium length (22–34), and 10 pairs in most dorsal position. All dorsal setae on soft cuticle on rounded tuberculate platelets bearing one or two glandular pores ( Fig. 24 ).

Soft dorsal cuticle with punctiform glands in line with setae S (gd6, gd7, gd8) and prominent gd9 glands lateral to Z5; four pairs of lateral prominent opisthonotal glands (gdl3, gdl6); at least five pairs of elongate lyrifissures discernible, including idl5 adjacent to gd9.

Idiosomatic venter ( Fig. 28 ). Except for anterior sterni-genital region, endopodals, and anal region, surrounding ventral integument is thin and flexible although densely punctate and pigmented in parapodal, exopodal II–III, III–IV, peritrematal and metapodal regions.

Anterior margin of sternal region slightly concave and ragged. Genital shield pear-like in shape, 222–225 long (including distal process), 145–153 wide at level of st4, nude, with punctate cuticle, anterior border with a triangu- lar acuminate process; anterior and laterals regions of shield fitted above integument of sternal shield surrounding genital opening. Sternal cuticle surrounding genital shield thin and flexible ( Fig. 30 ). Smooth sternal setae (st2–st5) borne around genital shield, of similar length (25–28); genital setae st5 shorter (13–14), behind posterior margin of genital frame, on darker platelets bearing 3–4 small glandular openings and iv5 at their sides; asymmetrically one, two or three pairs of glandular organs similar in shape to that of deutonymph (gst1, gst2, gst3), occasionally surrounded by punctiform pores; when glandular gst3 absent, minute glandular pores occupy their position in sternal region ( Fig. 26 ); iv 1 in front of st1.

Parapodal and peritrematal regions with punctate cuticle and shallow luminous pits as in deutonymph. Exopodal regions II–III form a lateral rib leaving peritrematal region on a concave surface. Peritremes long (236), Sshaped curved, extending from anterior border of coxae III to base of gnathosoma , with a short pre-stigmal paraxial projection. Poroidotaxy and adenotaxy of peritrematal region as in deutonymph, with glands or glandular groups gp1, gp2, gp3, gp4 and discernible ip2 ( Figs. 28, 29 ).

Anal shield sclerotized, conical and densely punctate, 83 long, 97 wide. Anal opening large, with hyaline valves and two pairs of minute, pectinate adanal setae (8–9). Opisthogastric region with 15–17 pairs of pectinate setae, short to medium length (16–34), eight or nine pairs on soft light cuticle and seven or eight on darkly pigmented metapodal region. Opisthogastric setae on basal sclerites which bear one to several glandular pores. Ventral region with six pairs of sclerites bearing one to several glandular openings; five pairs are in inguinal region, at position of glands gv2 (glandular group gv2); two pairs in pigmented ventral region, one in metapodal region (gv5) and one in ventral region (gv4); pair gv3 laterad anal shield; only three pairs of lyrifissures are discernible, including ivp.

Gnathosoma . Gnathotectum with one long medial prong bearing long lateral spines, with two basal serrate tectum at both sides. Cheliceral shaft slightly curved, 194–197 long, excluding basal segment; movable cheliceral digit 35 long, with one tooth; fixed digit conspicuous with a dorso apical tubercle bearing a globular sensilla and a dentate lamella attached to ventral region ( Fig. 27 ); dorsal setae smooth; pilus dentilis absent; margin of arthrodial envelope smooth. Deutosternum with two narrow transverse rows of denticles (2 teeth each). Hypostomal setae h1 55–60 long, h2 thinner, 31–33 long, as long as distance to base of h1, h3 75–80 long, and palpcoxal setae h4 21–28 long, clearly the shortest and thickest setae and with speculate tips ( Fig. 16 ). Corniculi elongated, digitiform, with blunt tips, well-separated from base to apex and relatively thinner than that of deutonymphal instar; long truncate-tipped, salivary styli and paralabrum as in deutonymph. Palps as described for deutonymph (142–155), palp trochanter with ventral spine and anterolateral serrate tectum; v1 61 long. Sternapophysis pentagonal in shape ( Fig. 17 ), with a wide base (44 widest level, 11 at anterior margin, 39 long), anterior border with a pair of dentate, triangular projections; base of laciniae 18 long with two setulose branches.

Legs. Leg chaetotaxy as described for deutonymphal instar. Leg lengths (excluding pretarsi): I (538-xx), II (564), III (420), IV (556). Ventrolateral anterior border of leg segment strongly serrate. Leg I tarsus ( Fig. 40 ) 166 long, about 3 times longer than tibia (53), with narrow, acuminate, rod-like process ( Fig. 41 ) and reduced chaetotaxy (4-23/5-4); tarsus IV 181 long. Tarsi II–IV with hyaline ventroapical process ( Figs 42–44 ), setae a d-1, pd-1 (34–42) longer than pretarsus to base of claws (28–34), and setae v-1, l-1, md, mv smooth with filamentous tips ( Fig. 42 ), other setae conical with lateral dentate tectum; a dorso apical gland opening; posterolateral basitarsal lyrifissure and gland pore present. Pulvilli of tarsi II–IV with acuminate central lobe and four lanceolate lobes ( Figs 33 , 38, 39 ). Coxae I with both ventral setae with serrate tips; coxae II–III with pv conical and serrate and coxae IV with ventral setae smooth. Legs II ( Fig. 43 ), both ventral setae on femora with serrate lamella; genua and tibiae II with ventral setae pv smooth and longer than serrate seta av-1; dorsal setae on femora-tibiae conical with lateral serrate lamellae, thicker than in male.

Description of adult male

Idiosomatic dorsum ( Fig. 31 ). Idiosomal shape similar to that of female, with prominent vertex, 759–780 long, 556–571 wide (n=3). Except for dorsal and anal shields and sterni-genital region, surrounding dorsal and ventral integument is flexible, although darkly pigmented and densely punctate in several regions.

Vertex lobed with lateral and round ventral tubercles, with setae j1, z1, four pairs x, and conspicuous gd1 gland.

Dorsal shield finely punctate, 620–632 long, 378–384 at widest level, and posteriorly 222 wide, with irregular borders; shield captures setae J5, Z4, Z5, which are slightly thicker and longer than other dorsal shield setae (18–20 long). Shield has approximately 32 pairs of short pubescent setae (8–11) (j2–j6, z2–z6, s1–s6, J1–J5, Z1–Z5, S3, S4, one seta jx, and five pairs “x”; each seta on dorsal shield with one or two gland pores at base; only one pair of glands (gd4?) and lyrifissures (idm3) discernible.

Surrounding soft cuticle with approximately 53–58 pairs of setae, heterogeneous in length (short, medium and long setae), medium and long setae stout with widened pilose heads; all setae with spiculate tips. This complement of setae includes setae s3, r1–r6, S5, S1–S5, R1–R6, and 37 pairs of complementary setae x. Setae laterally flanking shield in three irregular rows: first row with 17 pairs of setae, two pairs long, and two pairs of medium size; second row with 18 pairs of setae, six short pairs and 12 pairs long, longest caudal pairs 56 long; marginal-ventral third row with about 18–23 pairs of short setae. All dorsal setae on soft cuticle are on rounded tuberculate platelets bearing one or two glandular pores ( Fig. 31 ).

Soft dorsal cuticle with four discernible punctiform glands gd2, gd6, gd7, gd8; at least six pairs of elongate lyrifissures discernible.

Idiosomatic venter ( Fig. 34 ). Except for sterni-genital, endopodals, and anal regions, surrounding ventral integument is thin and flexible although densely punctate and pigmented in parapodal, exopodal II–III, III–IV, peritrematal and metapodal regions.

Anterior margin of sternal region slightly concave and ragged. Sterni-genital region with punctate cuticle, five pairs of sternal setae 13–17 long, thin and smooth sternal setae st1–st 3 in front of genital opening, st4 flanking opening and st5 posterior on a round glandular platelet; shield bears three pairs of conspicuous glandular openings (gst1–gst3), several punctiform glands, iv 1 in front of st1 and iv5 lateral to st5. Genital opening at level of coxae IV, 64 long, 58 wide, with two valves, anterior valve with one pair of eugenital (eu) setae and posterior valve with anterior margin dentate.

Parapodal and peritrematal regions with punctate cuticle and shallow luminous pits as in female. Exopodal regions II–III as in female. Peritremes long (245), S-shaped curved, extending from anterior border of coxae III to base of gnathosoma , without prestigmal paraxial projection. Poroidotaxy and adenotaxy of peritrematal region as in female, with complex glands gp2, gp3 and discernible ip2.

Anal shield lightly sclerotized, cone-shaped and densely punctate, 69 long, 125 wide; two pairs of minute, pectinate adanal setae (6–7), a pair of glandular pores ga ( Fig. 39 ); pair gv3 laterad anal shield. Opisthogastric region with 16 pairs of pectinate setae short to medium length (11–34), on basal sclerites with one glandular pore; gv2 and gv2x on sclerites with two openings; gv 4 in metapodal region; three pairs of lyrifissures are discernible, including ivp.

Gnathosoma . Gnathotectum as in female. Chelicerae 194 long excluding basal segment; movable cheliceral digit 33–35 long, with one tooth; fixed digit with conspicuous hyaline terminal process, one distal tooth, a cavity for attaching movable digit, and lamellar dentate molar region ( Figs 36, 37 ); globular dorsal sensilla indiscernible; dorsal setae smooth; pilus dentilis absent; margin of arthrodial envelope smooth. Hypostomal setae smooth, h1, h3 77–78 long, h2 21 long, as long as distance to base of h1 and thinner, and palpcoxal seta h4 24–25 long, thickest seta, with spiculate tips. Corniculi elongated, 92 long, digitiform, with blunt tips, well separated from base to apex ( Fig. 15 ) and relatively thinner than in deutonymphal instar; long and thin, truncate-tipped salivary styli, 116 long; paralabrum as in deutonymph, its tips exceed over short and pilose internal malae. Deutosternum with two rows of denticles, five and two, respectively. Palps as described for deutonymph, 181 long, palp trochanter with ventral spines and anterolateral serrate tectum ( Fig. 16 ), v1 flagellate, 91 long, v2 16 long. Presternal region, from anterior margin of sternal shield to base of subcapitulum with punctate soft cuticle; sternapophysis reduced to laciniae fused at base and free and setose branches distally ( Fig. 38 ).

Legs. Leg chaetotaxy as described for deutonymphal and female instars, with stronger segment. Leg lengths (excluding pretarsi): I (514), II (586), III (483), IV (569). Leg I tarsus (164) about 3 times longer than tibia (53); tarsus IV longest (192). Ventrolateral anterior border of leg segments strongly serrate. Leg II, femur, genu and tibia with seta av-1 modified as a spur with lyriform tip; av-1 on femur thumb-like, on femur and genu short and smaller; axillar seta pv-1 long and smooth ( Fig. 44 ); tarsus II with prominent ventral tips, with setae a d-1, pd-1 (45) longer than pretarsus to base of claws, ventral setae v-2 aligned with av-1 setae, spine-like with lyriform surface ( Fig. 32 ). Tarsus I, III, IV and pretarsus ( Fig. 45 ) III–IV as in female.

Studied material. The following material was collected at different depths and on different dates in caves at Cueva de la Fáraja, Canillas de Aceituno, in the Natural Park of the Sierra Tejeda, Almijara y Alhama, province of Málaga (southern Spain), coordinates X.402.392. Y. 4.082.650, 440 m.a.s.l, leg. Pablo Barranco: 1 protonymph, 1 deutonymph, at - 65 m depth (Tª 8 ºC, humidity 60%), 6/IX/2009; 1 deutonymph, at - 44 m, 2 deutonymphs at - 90m, 28/IX/ 2009; 1 deutonymph at - 65m (Tª 8ºC, 60% humidity,) 7 females, 3 males, 1 protonymph, 13 deutonymphs at - 52m, 16/V/2010.

Distribution and habitats. Uroseius sorrentinus was previously reported in a cave in central-southern Italy ( Cicolani & Manilla 1980). Other genera of the family, such as Polyaspinus Berlese, 1916 and Trachytes Michael, 1894 , are well represented in the Paleartic region, and have also been reported in caves, living on bat guano ( Pellegrini & Lopes Ferreira, 2013).

Caves provide a suitable habitat for small arthropods because of their darkness, high humidity, narrow temperature range, and frequent flooding which ensures high humidity. These environments, together with the fragmented structure of the habitat and reduced interspecific competition, could explain why the proportion of predators and phoretic mites is higher in caves ( Ducarme et al. 2004). While there are numerous mite species collected from caves ( Palacios-Vargas et al. 1998; Lundqvist et al., 1999; Culver et al., 2000), few supposed troglodite species have been reported ( Leruth 1939; Lebrun 1967) and U. sorrentinus does not seem to present attributes that support its troglodyte condition.

Remarks. Uroseius sorrenstinus belongs to the group of species characterized by adult females having the following attributes: idiosoma with a prominent vertex; medial dorsal shield not covering vertex but completely covering central posterior podonotal region; dorsal setae on shield similar in length and shape except for some longer posterior setae; other dorsal setae off shield heterogeneous in length and shape, some long, stout, with a widened distal region; genital shield with spine-like or acuminate anterior process.

Species sharing all these characters are U. foetidus Moraza & Pérez, 2019 and U. hunzikeri ( Schweizer, 1922) . In U. foetidus the female genital shield is narrow with a bifid spine-like process and medial dorsal shield with two pairs of long, thick setae with a pubescent head; its deutonymph has a dorsal shield covering the vertex with a network of polygonal punctate cells and lateral bands of pits; dorsal setae with a blunt tip and ventrianal shield with three pairs of setae. Females of U. hunzikeri ( Schweizer, 1922) have a genital shield bearing an acuminate process, a medial dorsal shield with more than two pairs of enlarged serrate or penicillate setae, and six pairs of opisthogastric setae. Its deutonymph has: an ellipsoidal-shaped ventrianal shield, with small and excavate posterior section; dorsal shield ornamented with rounded irregular cells; most dorsal setae brush-like bifid, excepting a few setae on the posterior and front region of the shield, which are cylindrical-conical and short.

Glands, lyrifissures and glandular fields. The larva and protonymph of Uroseius have the same complement of setae as the same instars of orthotaxic Gamasina mites ( Figs. 4a, b ). The described larva of Eutrachytes ( Fig. 1a, b ) has the same glandular pattern as in the Gamasina mites although its complement of dorsal lyrifissures is more reduced. However, since in the protonymph of Uroseius other opisthosomal lyrifissures “idm” and “idl” are observed ( Fig. 3 ), I assume that the poroids which appear at the larval instar in Gamasina delay their ontogeny to the protonymphal instar in Uropodina , or they simply were not detected in the described larva. Adults of orthoadenic Gamasina mites have a maximum number of eight pairs of dorsal glands (gd1, gd2, gd4–gd9) plus three pairs in the peritrematal region (gp1–gp3) and three ventral pairs (gv1, gv2, gv3). The known protonymph of Uroseius adds to this complement at least 12 more pairs of glands or gland openings: dorsal gdm1 *– gdm4 *, gdl1*–gdl5*, peritrematal gp0* and ventral gv4* and gv5*. These extra glands may be copies (plications) of gd1, gd2, gd4, gd5, gd6, gd4, gp1, gd7–gd9, gv3 and gv2, respectively.

In the deutonymphal instar of Uroseius there appears to be a neoadenic condition due to the phenomenon of the copying or plication of the existing protonymphal glands or gland openings together with neotrichy of the dorsal and ventral setae. Deutonymphs and adults may have glandular fields in the areas where the original protonymphal and larval glands were once found. This is very apparent in the peritrematal shield with glands gp3 and in the opisthogastric region where gst1 and gv2 duplicate into two or more glandular organs with one or more glandular openings.

A similar neoadenic condition has been described in several families of Gamasina mites. In Epicriidae , several glands of the protonymphal dotation duplicate ( Moraza 2005a, b), e.g. ventral gland gv2 is a dual gland with two glandular openings in some Epicrius (see Moraza 2005a, page 10, Figure 32 ), and in Zerconidae and Veigaia , gv2 may have a varying number of openings in the same platelets, creating one axillar glandular field.

In nymphs and adult Uroseius and other uropodid mites, gland openings look to be associated with dorsal setae, sharing the same platelet or situated near the alveolar seta.

Lyrifissures. The larva of dermanyssine Gamasina have a complement of 13 pairs of dorsal lyrifissures: four podonotal (id2, id4, id5, id6), eight opisthonotal (idx, ids, idm2, idm5, idl1–idl4,), one peritrematal (ip2), and four ventral (iv1, iv2, ivo1, ivp) ( Figs 2a, b ). The larva of Eutrachytes has dorsal lyrifissures id4, id6, idx, idl1, il2, ip2, iv1, ivp, and ivo ( Figs 1a, b ).

The protonymph of Gamasina adds to the protonymphal complement id1, idm1, idm3, idm4, idl5, idRp, ip3, ist, ivo2-ivo4 ( Fig. 3a, b ). Poroid id1 has been observed in deutonymphs of U. acuminatus , and idm1, idm 4 in deutonymphs of U. sorrentinus and U. foetidus , respectively; idRp may be one of the dorso-lateral lyrifissures. Trachytid mites may lack iv2 and ist, together with deutonymphal ip1 and iv3 present in Gamasina.

Legs. As in Gamasina, tarsus I–IV and femur I–IV in Uroseius have lyrifissures associated with the peripodomeric fissure, and the femur, genu and tibia of legs I–IV have a dorsodistal poroid. The dorso apical pore-like structure (glandular pore in Moraza & Pérez, 2019) in tarsi II–IV of Uroseius has been also found in tarsi II–IV of Epicriidae ( Moraza, 2005a) and has been observed in some Cercomegistina mites. The dorsal basitarsal pore has not been observed in other mites.

Regarding the apical process at the tip of tarsus I, it is clearly hyaline in U. acuminatus and U. foetidus , and is somewhat acuminate in U. sorrentinus . This structure may have a sensorial function and, because of its topographic position, may be a modified apical seta.

Figures

FIGURE 3. Uroseius sorrentinus Lombardini, protonymph. 3. Idiosoma, dorsal view; 4. Idiosoma, ventral view.

FIGURE 4. Protonymph of Spadiseius calyptrogynae, modified from Lindquist & Moraza, 2008: 4a. Idiosoma, dorsal view; 4b. Idiosoma, ventral view.

FIGURES 5–7. Uroseius sorrentinus (Lombardini), deutonymph. 3. Idiosoma dorsal view; 4. Detail of denoted dorsal setae; 7. Chelicera, fixed digit, ventral view, movable digit pointed.

FIGURES 8–13. Uroseius sorrentinus (Lombardini), deutonymph. 8. Idiosoma, ventral view; 9. Tritosternum; 10. Detail of peritrematal extension; 11–12. Detail of denoted ventral glands; 13. Detail of anal region.

FIGURES 14–19. Uroseius sorrentinus (Lombardini).14. Deutonymph, subcapitulum; 15. Deutonymph, detail of paralabrum and gnathotectum; 16. Female, detail of subcapitulum; 17. Female, tritosternum; 18. Male, subcapitulum; 19. Male, detail of palp-trochanter. (gnt: gnathotectum; prl: paralabrum; s.st.: salivary stile).

FIGURES 20–24. Uroseius sorrentinus (Lombardini), deutonymph, right legs I–IV, excluding pretarsus. 20. Leg I, dorsal view; 21. Leg II, dorsal view; 22. Leg III, dorsal view; 23. Leg IV, dorsal view; 24. Detail of dorsal setae.

FIGURES 40–48. Uroseius sorrentinus (Lombardini). 40. Female, tarsus I, posterolateral view; 41. Detail of distoapical process and sensorial setae of tarsus I; 42–44. Female, detail of pretarsus; 45. Male, detail of pretarsus; 46. Female, left leg II, femora-tibia, anterolateral view; 47. Male, right leg II, trochanter-tibia, anterolateral view; 48. Deutonymph, tarsus II, right leg, dorsal view. (ap: apical process; gl: gland pore).

FIGURES 25–27. Uroseius sorrentinus (Lombardini), adult female. 25. Idiosoma, dorsal view; 26. Detail of notate dorsal setae; 27. Chelicera, paraxial detail of cheliceral digits.

FIGURES 28–30. Uroseius sorrentinus (Lombardini), adult female. 28. Idiosoma, ventral view; 29. Detail of peritrematal region; 30. Genital shield.

FIGURES 31–33. Uroseius sorrentinus (Lombardini). 31. Male, idiosoma dorsal; 32. Male, tarsus II, anterolateral view; 33. Female, tarsus II, posterolateral view. Grey setae are ventral and lateral setae.

FIGURES 34–39. Uroseius sorrentinus (Lombardini), adult male. 34. Idiosoma ventral; 35. Male, detail of fixed digit, ventral view; 36. Detail of cheliceral digit; 37. Detail of genital opening; 38. Sternapophysis; 39. Anal shield.

FIGURES 1–2. Idiosoma larva. 1. Eutrachytes (E.) flagellatus, modified from Moraza et al., 2016: 1a. Idiosoma, dorsal view; 1b. Idiosoma, ventral view. 2. Spadiseius calyptrogynae, modified from Lindquist & Moraza, 2008: 2a. Idiosoma, dorsal view; 2b. Idiosoma, ventral view.