Tectoribates Berlese 1910
Creators: name: Behan-Pelletier, Valerie M.
name: Walter, David E.
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Sarcoptiformes
Oribatellidae
Tectoribates

description: Tectoribates Berlese 1910
Type species: Sphaerozetes (Tectoribates) proximus Berlese, 1910, p. 264
Synonym: Anoribatella Kunst, 1962, Type species: Anachipteria ornata Schuster, 1958, p. 90; Bernini (1973) p. 541
Included extant species:
Tectoribates proximus (Berlese, 1910), known from the Palaearctic and Neotropics; Tectoribates deserticola (Balogh & Mahunka, 1965), known from Mongolia; Tectoribates mongolicus Bayartogtokh, 1997, known from Mongolia; Tectoribates ornatus (Schuster, 1958) known from the Palaearctic and Neotropics.
Diagnosis. Adult. Species comprising this genus are unique among poronotic Brachypylina (Grandjean 1953b) in having the following combination of character states. Integument with micropuncta throughout. Rostrum with medial keel, or ridge extending from medial margin posteriorly to junction of lamella and prodorsum; rostrum with or without medial incision. Lamellae long, broad, following contour of prodorsum, with large cusps. Lamellar cusps effacing on prodorsum medially posterior to area of attachment of lamellae to prodorsum. Translamella absent. Bothridial wall distally expanded, with scales. Notogaster with posterior notogastral tectum, with immovable pteromorphs lacking anteroventral dens. Octotaxic system as 4 pairs of porose areas or saccules. Notogaster with 10 pairs of setae. Notogaster usually with, occasionally without, subsurface hexagonal pattern anteriorly. Lenticulus absent. Genal tooth present. Tutorium broad, lamelliform, cusp triangular. Discidium strongly curved lamina interlocking with proximal edge of trochanter IV. Epimere I with ’necklace’ of small tubercles anteriorly, extending between setae 1c. Epimeral seta 1c thickest seta. Genital plates with 6 setae. Postanal porose area present. Axillary saccule present. Palp tarsal eupathidium acm fused to solenidion. Legs heterotridactylous. Genua I and II with large ventral tooth. Seta s on tarsus I not eupathidial. Tarsus II with solenidion ω1 most proximal setiform structure; solenidia shorter than setae on tarsus II. One or two minute anterodorsal knobs or spines present on tibia I, close to solenidia φ 1 and φ 2.
Immatures: Deutonymph, Tritonymph. Apheredermous, plicate, without hysterosomal macrosclerites or excentrosclerites, cerotegument as tightly packed platelets, 1–4 in diameter, covering all of body and leg segments. Prodorsal porose regions present. Gastronotal setation unideficient; nymphs with 15 pairs of setae (f1, absent). Gastronotal setae of c, d, and l series monomorphic, phylliform; setae of p series phylliform as for other gastronotal setae, or setose. Lamellar, interlamellar setae and setae d of at least femora I and II phylliform. Opisthonotal gland present. Apodemato-acetabular tracheal system or porose homologues absent. Paraprocts atrichous in deutonymph. Cupule development normal. Bothridium cup-shaped. Humeral organ absent. Seta d present on tibiae I to IV and genua I to III.
Description. Adult. Integument. Cerotegument present laterally on podosoma, finely and densely granulate. Integument pitted with micropuncta throughout, puncta or foveae in area between genital and anal plate.
Prodorsum. Rostrum with dentate to almost smooth margin, with or without medial incision; medial keel extending from medial margin posteriorly to junction of lamella and prodorsum (Fig. 2C). Rostral setae long, heavily barbed laterally, directed anteromedially. Lamellae long, broad, following contour of prodorsum, with large, cusps; cusps parallel and closely adjacent medially, or diverging anteriorly; cusps with lateral dens, with or without medial dens, shorter or longer than lateral dens (Figs. 1, 2A, 4, 11 A, D, 12); lamellar cusps effacing on prodorsum medially, posterior to area of attachment of lamellae to prodorsum (Figs. 2A, C, 11A, D). Translamella absent. Longitudinal thickening present medially on lamella with nerve canal of seta le extending through thickness (Fig. 11D). Interlamellar setae subequal in thickness to lamellar setae. Exobothridial seta thin, finely barbed. Bothridial wall distally expanded, with scales, without lateral indentation (Figs. 1, 2A). Porose area Ad not evident. Dorsophragmata fused basally or separate.
Notogaster. Longer than wide, with immovable pteromorphs having smooth margins without dens anteroventrally (Fig. 2B). Anterior margin of notogaster undulating, without ridges in region lateral to bothridium. Anterior of notogaster with or without distinct hexagonal pattern in transmitted light (Figs. 1, 4, 11A, C, F, 12). Octotaxic system expressed as 4 pairs of porose areas or saccules (Figs. 1, 4, 11F, insert, 12); without sexual dimorphism. With 10 pairs of short setae; distance h1-h1 shorter than distance p1-p1; 5 pairs of lyrifissures present.
Lateral Region of Podosoma. Genal tooth short, blunt triangular, with longitudinal ridge ventrolaterally (Figs. 2E, arrow, 8D, 9D). Tutorium broad, lamelliform, cusp triangular, lying parallel to dorsal contour of prodorsum in lateral aspect, extending anterior of insertion of rostral seta (Figs. 2E, 9D). Ventrally directed rostral ridge ventral to rostral seta present or absent. Pedotectum I convex dorsally, without ventral depression (Fig. 11E, arrow). Pedotectum II present, without tubercle close to body wall. Custodium present, with short to long, free distal point (Figs. 2B, arrow, 5). Discidium strongly curved lamina interlocking with proximal edge of trochanter IV (Figs. 2B, 9A). Porose area Al present, proximal in position, difficult to see, because overlain by base of lamella and tutorium. Humerosejugal porose organs Am and Ah each expressed as porose area.
Ventral. Epimere I with single ‘necklace’ of small tubercles anteriorly, extending between setae 1c (Figs. 6, 8D arrow). Epimeral setal formula 3-1-3-3 or 3-1-2-3; seta 4c short and thin, seta 1c thickest seta (Figs. 2B, 6). Genital plates with 6 setae; 1 pair aggenital setae; 3 pairs adanal setae and 2 pairs anal setae (Fig. 6). Lyrifissure iad anterolateral to anal plate. Postanal porose area present (not evident on Fig. 6 because of curvature of ventral plate).
Gnathosoma. Axillary saccule present at base of palp (Fig. 11B, arrow). Chelicera chelate-dentate. Mentum with short tecta laterally, anterolateral of setae h, without recurved ridge distally (Fig. 2D, arrow). Palp setal formula 0–2–1–3–9(1); eupathidium acm shorter than solenidion, forming double horn with solenidion along length (Fig. 7E).
Legs. Heterotridactylous (Figs. 7A–D). Leg setal formulas I–IV, solenidia in parentheses (based on species described herein and T. proximus (Bernini 1973): I: 1-5-3(1)-4(2)-19(2); II: 1-5-3(1)-4(1)-15(2); III: 2-3-1(1)-3(1)- 15; IV: 1-2-2-3(1)-12. Genua I and II with large distally directed tooth ventrally (Figs. 7A, B, left arrow). Porose areas on femora I to IV and trochanters III and IV. Seta s on tarsus I not eupathidial, positioned distal of setae (a). Tarsus II with proximal solenidion ω1 most proximal setiform structure on segment; solenidia on tarsus II shorter than setae on segment (Figs. 7B right arrow, 2C). Femur III with seta l’ present; seta v' of genua I and II present. On genua and tibiae I and II setae l” thicker, more heavily barbed than l’. One or two minute anterodorsal knobs or spines present on tibia I close to solenidia φ 1 and φ 2 (Fig. 9C, arrow).
Remarks. 1. The hexagonal pattern present anteriorly on the adult notogaster in most (but not all) species of Tectoribates is a cuticular structure not visible on the surface, i.e., not visible with SEM (Figs. 8A, B). It has the same position as the lenticulus or “clear-spot” of many taxa, however, there is no difference in pigmentation of the cuticle associated with the hexagonal pattern. Whether this is a light sensory structure, as with the lenticulus of Oribatella Banks, 1895, (Alberti & Fernandez 1990) is unknown.
2. In Tectoribates the lamellar cusps do not fuse, rather they efface (merge) on the prodorsum posterior to the region of attachment of the lamella to the prodorsum. In many poronotic Brachypylina, lamellar cusp fusion is at the region of attachment of the lamella to the prodorsum, e.g., the mycobatid Selvazetes Behan-Pelletier 1998. Alternatively, fusion of lamellar cusps can be anterior to the area of attachment of the lamella to the prodorsum, and a ‘pocket’ is formed, e.g., the oribatellid Ophidiotrichus and many species of Oribatella (Behan-Pelletier & Walter 2012). In Tectoribates, the area of attachment of the lamella to the prodorsum is outlined by thicker integument on Figs. 11 A, D; but dorsomedially the lamellar cusps efface on the prodorsum posterior to this region. This gives the appearance of a narrow cleft extending posteriorly from the region of lamellar attachment to the prodorsum medially.
3. Coxisternal setation. Bernini (1973) gave an epimeral setation of 3-1-3-3 for both Tectoribates proximus and T. ornatus, though seta 3c does not appear in his illustration of the venter of T. proximus. Similarly, Bayartogtokh (1997) did not show seta 3c in his illustration of the venter of T. mongolicus and Balogh and Mahunka (1965) did not describe or illustrate the epimeral setation of T. deserticola. The three North American species of Tectoribates, described below, have an epimeral setation of 3-1-2-3. It is clearly seta 3c that is absent, as seen by comparing the region lateral of the custodium in Fig. 9A with that in Oribatella species (e.g. Figs. 29A–D in Behan-Pelletier and Walter 2012). The ease of misinterpretation of setation on epimeres III and IV in Brachypylina was discussed in detail by Sidorchuk & Norton (2010; their Miscellaneous morphological remarks, 4).
4. We attributed immatures to Tectoribates alcecampestris and T. borealis (see below) for several reasons. First, they co-ocurred in samples with adult Tectoribates and were of appropriate size. Other brachypyline adults of similar size that were present in these samples included species of Autogneta Hull, 1916, Banksinoma Oudemans, 1930, and Tectocepheus Berlese, 1896, but immatures of these genera are already known and are distinctly different from our suspected Tectoribates nymphs: representative works include Grandjean (1960) (Autogneta), Ermilov (2010) (Banksinoma) and Pfingstl and Krisper (2011) (Tectocepheus). In addition, the immatures described below share two important traits with Tectoribates adults that are not found in adults or immatures of these other genera: they have an axillary saccule at the base of the palp, and the palp solenidion is fused along the distal half of its length with euapthidium acm. However, proximal solenidion ω1 on tritonymphal tarsus II is in line with seta ft’ rather than being the most proximal setiform structure on segment.
5. Bernini (1973) did not consider Tectoribates africanus Balogh, 1959, a member of the genus, on the basis of the morphology of the rostrum and the lamellar cusps. He did not record seeing specimens, nor suggest another placement for this species. Balogh and Balogh (2002) placed this species in the oribatellid genus Plakoribates Popp, 1960, however, Subías (2004, 2013) retained this species in Tectoribates. We do not consider it a member of Tectoribates, because of the cup-shape morphology of the bothridium, but cannot suggest another placement for the species.
6. The genus Pseudotectoribates Subías, 1977, with Anachipteria subsimilis Mihelčič, 1956 (= P. bellus Subías, 1977). as type species, is similar in appearance to Tectoribates, a fact remarked on by Schuster (1958) and Bernini (1973). The genus was defined by Subías (1977) as having lamellae independent along their length, a bothridial seta (sensillus) that is truncated distally, a notogaster with 4 pairs of porose areas and 13 pairs of setae. The three included species are heterotridactylous, as are Tectoribates spp. The illustration of P. subsimilis shows the distinctive hexagonal pattern that is found anteriorly on the notogaster of many species of Tectoribates (Subías 1977, Fig. 200). Pérez-Iñigo (1993) and Subías (2004, 2013) considered this genus a member of Oribatellidae. We have examined specimens of the type species Pseudotectoribates subsimilis from Spain (Madrid, Valdelaguna, collector, L. S. Subías) and specimens of Pseudotectoribates sp. from Montpellier, France (collector, W. Knülle) and they differ from the diagnosis of Tectoribates only in having 13 pairs of notogastral setae. The lamellar cusps are independent and efface on the surface of the prodorsum, as in Tectoribates, and the necklace of tubercles extending between epimeral setae 1c is present ventrally.
7. Sidorchuk and Norton (2010) established a neotype and provided a photograph for the Eocene Baltic amber species Tectoribates parvus Sellnick, 1931. As they noted this species was transferred from Tectoribates to Unduloribates Balogh, 1943, by Krivolutsky et al. (1990) and listed among Oribatellidae by these authors, based only on the original description. They noted the resemblance to Unduloribates in general appearance, but that the length of 264 Μm, is “less than half the length of the smallest reported extant Unduloribates specimen”. Because of the poor condition of the specimen they could not classify this species and its placement awaits further study.
Descriptions
Tectoribates alcescampestris sp. nov. (Figs. 1, 2A–E, 3, 11 A, B)
Material examined. Holotype: adult female, Canada, Alberta, Lamont Co., Moose Pasture, 11 km S Lamont, aspen litter under snow (53.654167, -112.762778), 22 January 2012 (D.E. Walter), deposited in the CNC, type number 24148. Paratypes 4 females, 2 males with same data as holotype; same location, all (53.656667, - 112.759444), (D.E. Walter), 1 female ex littoral moss on margin of slough, 1 June 2008; 1 adult ex Pleurotus ostreatus on aspen log, 16 July 2011; 2 females ex lichen, moss and polypore fungus from aspen log, 11 March 2012, 3 males, 1 female, 1 deutonymph, 1 tritonymph from lichen, moss and polypore on wood; Alberta: ABMI site 1635 NW, (49.41763, -113.99814), 5 km south-west Pincher Creek ex grass, sedge sod, 12.vi.2008; 4 males, 2 females ABMI site 1412, NE, SE (51.39874, -112.25328) ex prairie sod, 31 May 2012; 2 females, ABMI site 1192 NE (52.66613, -110.69303), ex litter in upland aspen mixed woodland, 19 June 2008. Paratypes deposited in the PMAE.IZ, CNC, USNM, and RNC.
Other material examined. Additional individuals from the type locality were studied under the scanning electron microscope.
Diagnosis. Adult. Total length 275–305. Micropuncta between genital and anal plates subequal in size, though more spaced than micropuncta on rest of body. Rostral margin smooth, with medial V or U-shaped indentation. Notogaster anteriorly without distinct hexagonal pattern. Notogaster with porose areas, 5-8 in diameter. Notogastral setae smooth, 15–27, with seta c longest; lm posterior or medial to Aa and lp anterior to medial of A1; mutual distance of h1–h1 about 28, of p1–p1 about 44. Lamella about 79 long, of which cusp 37–41; 11–14 wide at level of insertion of seta le. Lamellar cusps parallel medially or diverging anteriorly. Lamellar cleft extending posteriorly about 5–9 from area of attachment of lamella to prodorsum; distance between lamellae in this region (width of cleft) about 4. Lamellar cusp with short pointed lateral dens, 8–12 long, medial dens absent. Lamellar seta arising anteriorly on cusp, about 40 long. Bothridial seta club-shaped, 59–64. Seta ex about 23. Tutorium 69– 72 long, of which cusp about 32. Custodium 10–12 long. Epimeral seta 1c about 30.
Description. Adults. Dimensions: Total length: females (n = 2) 303 (300, 305); males (n = 4) 289 (range 275– 300). Notogastral width: females (n = 2) 200 (200, 200); males (n = 4) 198 (range 190–200).
Integument: Prodorsum, notogaster, pedotecta, anal plates, genital plates, venter and mentum micropunctate; puncta between genital and anal plates subequal in size, more widely spaced than micropuncta elsewhere on body (Fig. 2B). Lamellae, pedotectum, mentum, coxisternal region with fine irregular striae (Fig. 2); tutorial cusp with distinct striae (Fig. 2E).
Prodorsum: Rostrum with distinct, strongly convex medial crest, rostral margin smooth, with medial U to Vshaped indentation (Figs. 2C, E). Rostrum with deep, cerotegument-filled groove, ventral to seta ro (Figs. 2D, E). Cerotegument thickly developed in area defined by this groove and genal tooth. Lamella about 79 long, of which cusp 37–41; 11–14 wide at level of insertion of seta le. Lamellar cusps parallel medially or diverging anteriorly. Lamellar cleft extending posteriorly about 5–9 from area of attachment of lamella to prodorsum; distance between lamellae in this region (width of cleft) about 4. Lamellar cusp with short, pointed lateral dens, 8–12 long, medial dens absent. Seta ro 48–54 long, strongly barbed along length, acuminate, curved anteromedially. Lamellar seta arising anteriorly on cusp, about 40 long, heavily barbed, acuminate distally. Seta in about 72 long, barbed (subequally to le), acuminate; mutual distance about 33 (Fig. 1). Bothridial seta club-shaped, 59–64 long, with barbed, rounded head directed slightly anteromedially (Figs 1, 2E). Seta ex thin, weakly barbed, about 23. Dorsophragmata separate at base.
Lateral region of podosoma: Tutorium 69–72 long, of which cusp about 32. Custodium 10–12 long (Fig. 2B). Porose area Al about 8 in diameter (difficult to see because of proximal position).
Notogaster: Slightly longer than wide: 1.1:1. Anteriorly without hexagonal pattern. Octotaxic system expressed as porose areas, 5–8 in diameter. Setae smooth, 15–27, with seta c longest; lm usually medial to Aa, sometimes posterior to (Fig. 1); lp usually anterior or medial to and closely adjacent A1; mutual distance of h1–h1 about 28, of p1–p1 about 44.
Ventral Region: Epimeral setae mostly about 7–30 long, barbed, acuminate, with 1c more heavily barbed, and thicker than other epimeral setae, about 30; 1a, 2a, 3a, 4a, 4c about 7, 1 b 11–16 3 b, 4b 14–18, 3 c absent. Genital, aggenital, anal and adanal setae smooth; genital setae about 10, others about 6. Genital setae 3+3. Lyrifissure iad anterolateral of anal plate. Postanal porose area about 9 x 5.
Gnathosoma: Small axillary saccule present at base of palp, 6 x 2 (Fig. 11B). Cheliceral length 60–70. Mentum with small tectum, anterolateral of seta h; without recurved ridge distally (Fig. 2D, arrow). Length of seta m>a>h.
Legs: Setae l” of genua and tibiae I and II more barbed than other setae on these segments, l” genu II spinose; l” genu and tibia I about 14 and 17, l” genu and tibia II about 14 and 20, respectively.
Description. Immatures Dimensions: Total length: deutonymph (n = 1) 288; tritonymph (n = 1) 312.
Tritonymph. Integument: Sclerotized with light brown coloration. Cerotegument of tightly packed platelets, about 1 in width covering all of body and leg segments.
Prodorsum: Aspis with transverse porose area posterior to setae in and bothridia. Lateral porose areas present anterior of bothridia (porose areas not illustrated in Fig. 3 because of difficulty in removing cerotegument). Seta ro finely barbed along length, tapered, about 27 long. Seta le barbed, phylliform, about 20 long, 10 at maximum width. Seta in barbed, phylliform, about 26 long. Mutual distance of setae ro-ro, le-le and in-in about 18, 22 and 52, respectively. Seta ex about 7 long, thick, heavily barbed, penicillate. Bothridial seta 60–66 long, barbed, clavate, head subequal in length to stalk, more tapered than that of adult.
Gastronotic Region: Integument without sclerotization; orientation of plicae more transverse anteriorly, more longitudinal posteriorly (Fig. 3). Setae of c, d, l, and h series about 17–26 long, with seta c3 shortest seta (Fig. 3). Setae of p series (visible only in ventral aspect); p1 narrow, barbed, phylliform, about 14, p2 heavily barbed, tapered, about 14, p3 barbed, tapered, about 14. Mutual distance of setae da-da, dm-dm and dp-dp about 51, 33 and 23, respectively.
Ventral Region: Medial margin of epimeral plates weakly defined. Epimere I with narrow mentotectum developed laterally. Epimeral, genital, aggenital, anal and adanal setae smooth, acuminate, about 10 long. Porose integument surrounding opening of opisthonotal gland not evident (possibly because area covered by cerotegument).
Gnathosoma: Axillary saccule present. Palpal eupathidium acm attached to solenidion along distal threequarters of solenidial length (as for adult).
Legs: Proral setae of tarsus I appear eupathidial. Subunguinal seta of tarsus I of normal form and inserted proximal to antelateral pair as in adult. Porose areas present on femora I to IV. Distal setae on tarsi I–IV blunt. Setae d of femora I and II barbed, phylliform; seta d of femur III narrow, phylliform; seta d of femur IV barbed, tapered. Solenidion and coupled seta d on tibia I on anterodorsal tubercle. Solenidion φ on tibia II and III subequal in length to seta d; solenidion φ on tibia III 4 /5 length seta d. Solenidia δ on genua I, II and III 4 /5 length seta d.
Deutonymph. As for tritonymph, except overall size and length of setae proportionally smaller.
Development. Development of epimeral setae (deutonymph to adult): 3-1-2-2, 3-1-2-3, 3-1-2-3. Genital, aggenital, anal and adanal setae (deutonymph to adult): 3-5-6, 1-1-1, 0-2-2, 2-3-3, respectively.
Development of leg setae and solenidia given in Table 1.
Etymology. The specific epithet, alcescampestris, is the Latin for the type locality – Moose Pasture.
Remarks. This species is unique among known Tectoribates in lacking the hexagonal pattern on the anterior of the notogaster in the region commonly occupied by a lenticulus in brachypyline taxa. Whether this absence is a plesiomorphy or a secondary loss is unknown.
Tectoribates alcescampestris has been collected primarily in aspen parkland in forest litter and fungal sporocarps and in other open sites covered by grasses and sedges. Gravid females carry up to 2 large eggs. Gut contents are primarily lightly pigmented fungal hyphae and spores. The association of immatures with adults was addressed under the Discussion following the generic diagnosis (See above, Remark 4).
description: Published as part of Behan-Pelletier, Valerie M. & Walter, David E., 2013, Phylogenetic relationships of Tectoribates: nymphal characters of new North American species place the genus in Tegoribatidae (Acari, Oribatida), pp. 459-489 in Zootaxa 3741 (4) on pages 461-469, DOI: 10.11646/zootaxa.3741.4.2, http://zenodo.org/record/247812