Tegoribates Ewing, 1917

Behan-Pelletier, Valerie M., 2017, Tegoribatidae of North America, with proposal of Protectoribates gen. nov., and new species (Acari, Oribatida, Tegoribatidae), Zootaxa 4337 (2) : 164-166

Tegoribates Ewing, 1917 Type species: Tegoribates subniger Ewing, 1917

Synonym: Lepidoribates Sellnick, 1920 . Type species: Zetes latirostris C. L. Koch, 1844

Included extant species:

Tegoribates subniger Ewing, 1917 ; known from Indiana, USA.

Tegoribates americanus Hammer, 1958 ; known from the western Nearctic , Russian Far East, Argentina and Vietnam. Tegoribates bryophilus Woolley, 1965 ; known from Colorado, USA.

Tegoribates latirostris ( Koch, 1844) (Zetes) (= Oribata alzanii Coggi, 1900 ); known from the Palaearctic. Tegoribates montana Engelbrecht, 1986 ; known from South Africa

Tegoribates natalensis Engelbrecht, 1986 ; known from South Africa

Tegoribates nuda Engelbrecht, 1986 ; known from South Africa

Revised diagnosis: Adults: With character states of Tegoribatidae ( Grandjean (1953, 1954), Woolley (1965) Fredes & Martínez (2016), and see below). Prodorsum with lamellae fused medially. Genal tooth absent; open taenidium present in usual position of genal incision, extending to acetabulum I. Humerosejugal organs Am, Ah present as porose area; Al absent. Dorsophragmata fused medially, elongated. Pedotectum I large, extending to base of bothridium. Bothridium cup-shaped, positioned laterally, closely adjacent to lamella, with anterior pointed scale. Notogaster with continuous posterior tectum; pteromorphs with hinge; lenticulus present or absent. Notogastral setation 10 pairs; setae apobasic. Octotaxic system developed as porose areas or saccules or tubules. Genital setation 6 pairs. Postanal porose area present. Subcapitular mentum with complete tectum. Axillary saccule of subcapitulum present. On palptarsus eupathidium acm running parallel to solenidion (Acm S of Grandjean 1954), but bases slightly separated. Femur I long, with medial, distinct bend. Tibia IV with solenidion. Tibia II and tarsus II without anterodorsal carina. Monodactylous or heterotridactylous.

Immatures: Plicate, eupheredermous, line of dehiscense complete, without hysterosomal macrosclerites or excentrosclerites, at least partially tuberculate; cerotegument as tightly packed platelets, 1–2 in diameter, covering all of body and leg segments. Prodorsal porose regions present. Gastronotal setation unideficient; larva with 12 pairs, nymphs with 15 pairs of setae (f1 absent). Gastronotal setae dimorphic with those of c, d and p series similar, setose; some or all setae of l and h series brush-like. 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 microtuberculate throughout; U-shaped shallow groove extending from coxisternal region to posterior of anal plates ( Figs. 10 , 21B ).

Prodorsum. Rostrum with smooth margin, without medial incision; weak medial keel extending posteriorly to underneath lamella ( Fig. 21C, D ). Rostral setae heavily barbed laterally, directed anteromedially ( Fig. 11 ). Lamella long, pair fused, covering all of prodorsum in dorsal aspect ( Fig. 9 ), with faint longitudinal line medially (visible with light microscopy), with almost parallel areas accommodating nerve canal for seta le ( Figs. 8F , 22A ). Lamella with short, V or U-shaped indentation anteriorly; concave posterolaterally, accommodating bothridium ( Figs. 8E , 13B , 21D ). Seta le arising dorsally on lamella ( Figs. 9 , 17 , 20 ). Interlamellar setae subequal in thickness to lamellar setae. Exobothridial seta present, or absent; alveolus usually present. Bothridial wall expanded anterodorsally with pointed scale, otherwise cup-shaped, without lateral indentation ( Figs. 13B , 22A ). Porose area Ad present. Dorsophragmata fused ( Figs. 9 , 17 , 20 ).

Notogaster. Longer than wide; with hinged pteromorphs having smooth margins without dens anteroventrally ( Figs. 19B , 21D , 22B ). Anterior margin of notogaster straight, transverse, without ridges in region lateral to bothridium ( Fig. 9 ). Anterior of notogaster without hexagonal pattern in transmitted light. Octotaxic system expressed as 4 pairs of either porose areas, saccules or tubules ( Figs. 8D , 9 , 17 , 20 ); without sexual dimorphism. With 10 pairs of short setae.

Lateral Region of Podosoma. Genal incision and genal tooth absent; open taenidium present in usual position of genal incision, extending to acetabulum I ( Figs. 8B , 13A , 21E ). Tutorium narrow, lamelliform, cusp triangular, lying parallel to dorsal contour of prodorsum in lateral aspect, extending anterior of insertion of rostral seta ( Figs. 11 , 13A ). Pedotectum I flattened or rounded dorsally, pointed distally, without ventral depression ( Fig. 11 ). Pedotectum II present, without tubercle close to body wall. Custodium present as very short extension to circumpedal carina ( Figs. 8F , 11 , 19E , 22C ). Discidium strongly curved lamina ( Fig. 8F ). Porose area Al absent. Humerosejugal porose organs Am and Ah present, expressed as porose areas ( Figs. 8E , 11 ).

Ventral. Epimere I without necklace of small tubercles anteriorly. Epimeral setal formula 3-1-3-3. Genital plates with 6 setae, 3 setae on anterior margin; 1 pair aggenital setae; 3 pairs adanal setae and 2 pairs anal setae ( Fig. 10 ). Lyrifissure iad at anterolateral edge of anal plate ( Fig. 11 ). Postanal porose area present ( Fig. 13E ). Band of darker integument absent between genital and anal plates. Preanal organ large cup-shaped ( Fig. 8C ).

Gnathosoma . Axillary saccule present at base of palp. Chelicera chelate-dentate ( Fig. 13C ). Mentum with tectum covering camerostome when elevated ( Figs. 10 , 21C, E ). Palp setal formula 0-2-1-3-9(1); eupathidium acm subequal to solenidion, forming double horn with solenidion along length, bases slightly separate ( Fig. 8G ).

Legs. Monodactylous or heterotridactylous. Leg setal formulas I–IV, solenidia in parentheses: I: 1-5-3(1)-4(2)- 20(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 without tooth ventrally ( Figs 12A, B ). Porose areas on femora I to IV and trochanters III and IV. Femur I with obtuse bend medially ventral to seta d ( Fig. 12A , Fig. 22E ). Tibia II without anterodorsal dentate carina. Seta s on tarsus I eupathidial, positioned distal of setae (a). Solenidia on tarsus II shorter than setae on segment; ω1 not most proximal setiform structure on segment;. Genua I and II with distinctive and spinous seta l” ( Figs. 12B , 19F , insert, 21C). Femur III with seta l’ present; seta v' of genua I and II present. On tibiae I and II seta l” slightly more spinous than l’. Anterodorsal knobs or spines absent from tibia I.

Remarks. 1. Sellnick (1920) proposed Lepidoribates to accommodate Zetes latirostris Koch. Jacot (1929) considered it a junior synonym of Tegoribates and this was recognized by Sellnick (1955) and subsequent authors.

2. Other than a brief comment on larva and nymphs of T. americanus ( Behan-Pelletier 2001) , immatures of Tegoribates have been known only for T. latirostris (larva and nymph; Tuxen 1943, Grandjean 1954, Norton and Ermilov 2014). Tuxen (1943 Figs 12 , 13 ) described a “spinous knob” on the dorsal of the hysterosoma of the larva; this is the hysterosomal region bearing setae dp, as found in other species of Tegoribates , described below.

3. Grandjean (1954) diagnosed Tegoribates as lacking a genal notch. This is the case in all described species. However, a taenidium is present in the same region in all members of this genus, running from close to the border of the rostrum posteriorly to acetabulum I. Following the terminology of Grandjean (1968; see also Travé 1986), this appears to be a “respiratory taenidium”, which he defined as a furrow, almost closed or not, banded or smooth, hollowed into the integument, and communicating with the stigma of trachea I or with those of tracheae I, sejugal and III. The taenidium of Tegoribates extends to acetabulum I, and possibly communicates with trachea I. A taenidium, with a similar morphology, is found in the same region in the licneremaeoid genus Phylleremus, which is a unique expression in the superfamily ( Behan-Pelletier & Walter 2007). A ‘taenidial gutter’ is also found on the prodorsum of the oppioid Hypogeoppia belgicae Wauthy & Ducarme, 2006 . Travé (1986) noted how easy it is to overlook this structure. When viewed with incident illumination of flattened, slide-mounted specimens the taenidium appears as in Figs. 8B , 13A , and 19A ; on heavily sclerotized whole-mounts, it has the appearance indicated in Figs 21 D, E . This is the lateral structure outlined by Engelbrecht (1986) on the prodorsum of Tegoribates natalensis (his Fig. 65). Hypozetes also lacks a genal notch, and while the rostral ridge has a narrow tectum there is no evidence of a taenidium ( Behan-Pelletier 2001, her Fig. 3 ).

4. The octotaxic system in Tegoribates is developed in various forms. Grandjean (1953, 1954) noted that the octotaxic system is represented by 4 pairs of small “trachea”, called ‘tubules’ by Norton et al. (1997; their Fig. 5l ) and herein. This is the expression of the octotaxic system in T. latirostris and T. subniger (see below), and these tubules are closely associated with setae. I follow Norton et al. (1997) and use the notation Ta, T1-T3 for these structures, corresponding to the notation for porose areas (Aa, A1–A3) and saccules (Sa, S1–S3). Norton et al. (1997) also noted the presence of tubules in Plakoribates . Fine tubules also are found in the ceratozetoid genera Lamellobates, Paralamellobates and Sacculozetes , but these are not closely associated with setae. Woolley (1965) expanded the diagnosis of Tegoribates to include T. bryophilu s with the octotaxic system of saccules, an expression also found in T. americanus . The expression of the octotaxic system is further expanded in T. walteri sp. nov. (described below) to include porose areas. The close association of the octotaxic system with setae is most evident in T. latirostris and T. subniger . Other genera of poronotic Brachypylina have the octotaxic system as either porose areas or saccules, according to species (e.g., Ceratozetidae : Trichoribates , Achipteriidae : Anachipteria , Tegoribatidae : Tectoribates ); only Tegoribates includes species with either porose areas, saccules or tubules.

5. A distinct apomorphy of all known species of Tegoribates is femur I distinctly bent to an obtuse angle near the level of seta d. Femur I is also relatively longer than in other genera of Tegoribatidae where legs have been studied; e.g., compare Figs 12A , 22E with Fig. 4A herein, and Fig. 7A ( Behan-Pelletier & Walter 2013), Fig. 21 ( Ermilov & Anichkin 2013), Fig. 3A ( Ermilov & Minor 2015) and Fig. 2A ( Fredes & Martínez 2016). This elongated and bent femur I could possibly be a modification to accommodate the depth of the prosoma of Tegoribates , and the associated length of pedotectum I ( Fig. 22E ).

6. The preanal organ of Tegoribates ( Fig. 8C ) is most similar to that of Podacarus auberti Grandjean (1955) (Podacaridae) with a large, wide cup, the anterior face of which serves for attachment of muscles for the genital aperture, and protuberance ob. It differs in that the struts for P. auberti are parallel; those of Tegoribates are directed laterally at an obtuse angle. The preanal organ has not been studied in much detail in poronotic Brachypylina other than by Grandjean (especially Grandjean 1969). This character seems to be highly variable in Tegoribatidae , with that of Protectoribates ( Figs. 22F, G ) different from any described to date. In contrast, that of Tectoribates ( Fig. 22I ) is similar to that of described Ceratozetoidea (e.g., Euzetes ; Grandjean 1969). The preanal organ of Hypozetes is similar to that of Tectoribates , except that the cup is very wide and the struts are thick, strongly sclerotized and parallel ( Fig. 22H ),

7. Ermilov and Minor (2015) disagreed with the transfer of Tegoribates montana Engelbrecht, 1986 and T. nuda Engelbrecht, 1986 (both from South Africa) to Neophysobates by Subías (2004, 2017) and these species are retained in Tegoribates herein. Similarly, Fredes and Martínez (2016) questioned the change in classification of Tegoribates natalensis Engelbrecht, 1986 to Paraphysobates by Subías (2004), and this species is also retained in Tegoribates herein.

8. A tutorium is present, but difficult to see, in Tegoribates species as it is overlain by the lamella dorsally and the pedotectum laterally. This possibly explains the absence of this character from previous descriptions of species.

Figures

FIGURE 4. Protectoribates occidentalis sp. nov., adult female, A, leg I, B, leg II, C, leg IV, all antiaxial aspect. Legs I and II, trochanter not illustrated. Scale bar = 20 µm.

FIGURE 5 A – E. Protectoribates occidentalis sp. nov., scanning electron microscope images of adult female from California; A. habitus dorsal; B, habitus ventral, with arrow to custodium; C, frontal aspect; D, dorsolateral of prodorsum, with arrow to spindle end of bothridial seta (bo), second arrow to genal incision and third arrow to carina on tibia II; E, ventrolateral of prodorsum, with arrow to ridge on genal tooth. Scale bars: A, B = 25 µm, C – E = 15 µm.

FIGURE 7. Protectoribates occidentalis sp. nov., differential interference contrast microscope images, A – E adults; A, bothridium and bothridial seta (5 layers), with arrow to nerve canal of seta le on lamella; insert of bothridium showing scales; B, custodium and discidium (3 layers), with arrow to broad, rounded anterior edge of custodium; C, porose organ Ah, lateral view, with arrow to surrounding cerotegument (3 layers); D, dissected specimen with Ah in direct view (2 layers); E, genu, tibia and tarsus II, with white arrow to dentate carina on tibia (2 layers) and narrow black arrow to seta pv ”; F, protonymph (2 layers), dorsal view. Scale bar: A = 25 µm; B = 10 µm; D = 7.5 µm; F = 50 µm.

FIGURE 8 A – H. Tegoribates subniger Ewing, differential interference contrast microscope images of adult. A, holotype specimen, Type No. 2009427, housed in USNM; B, lateral of prodorsum with arrow to taenidium; C, preanal organ indicated by arrow; D, region of tubule T 1, h 3 and gla, with small arrows to tubule and large arrow to its opening (3 layers); E, lamella (5 layers), with arrow to nerve canal for seta le, lateral of podosoma displaced so Ah visible, black arrow to fused dorsophragmata; F, ventral region showing discidium (dis) and circumpedal carina (cc), with arrow to minute custodium (3 layers); G, pedipalp (5 layers), with arrow to solenidion ω. Scale bars: A = 100 µm; C, D, F = 25 µm; E = 40 µm; G = 30 µm.

FIGURE 9. Tegoribates americanus Hammer, adult female, dorsal aspect, legs not illustrated, with arrow to fused dorsophragmata. Scale bar = 50 µm.

FIGURE 12 A – C. Tegoribates americanus Hammer, adult female, legs, all antiaxial aspect (trochanter not shown in A, B): A, leg I, with arrow to bend in femur; B, leg II (femur to tibia), C, leg III. Scale bar = 20 µm.

FIGURE 13. Tegoribates americanus Hammer, differential interference contrast microscope images of adult. A, lateral of prodorsum (6 layers) with arrows to taenidium; B, bothridial seta and bothridium, with arrow to anterior scale; C, chelicera, pedipalp and rutellum showing size relationship, supracoxal seta e, and with arrow to axillary saccule (5 layers); D, tarsus II, showing shape of seta pv ”; E, postanal porose area. Scale bars: A, B = 50 µm; C = 25 µm.

FIGURE 19. Tegoribates bryophilus Woolley, differential interference contrast microscope images of adult type material. A. anterior of prodorsum (note, specimen broken), with arrow to taenidium; B, pteromorph; C, saccule Sa and seta lm; D, posterior of prodorsum with arrow to fused dorsophragmata (3 layers); E, lateral of coxisternal region showing circumpedal carina and discidium; F, lenticulus; G, seta l ” of genu II. Scale bars: A, B, E = 50 µm; C, = 10 µm; D = 35 µm.

FIGURE 20. Tegoribates walteri sp. nov., adult male, dorsal aspect, legs not illustrated. Scale bar = 100 µm.

FIGURE 21. Tegoribates walteri sp. nov., scanning electron microscope images of adult female from California, A. habitus dorsal, with arrow to spine-like seta l ” of genu II; B, habitus ventral, with arrow to ventral depression; C, frontal aspect, with arrows to spine-like setae l ” of genua I and II; D, anterolateral of prodorsum and part of notogaster, with arrow to spine-like seta l ” of genu II; E, ventrofrontal aspect, with arrow to taenidium. Scale bars: A, B = 50 µm; C-E = 25 µm.

FIGURE 22. Differential interference contrast microscope images of adults; A – D, Tegoribates walteri sp. nov., A, part of prodorsum (4 layers) showing lamella, bothridium, bothridial seta, interlamellar seta, with arrow to fused dorsophragmata; B, hinged pteromorph (3 layers); C, coxisternal region showing custodium (arrow) and pedotectum II (3 layers); D, porose area Aa and surrounding muscle sigillae (5 layers). E, Tegoribates subniger Ewing, lateral of podosoma, showing elongated, bent femur I (indicated by arrow); F, G, Protectoribates occidentalis sp. nov., detail of preanal organ; H, Hypozetes laysanensis Aoki, detail of preanal organ; I, Tectoribates borealis Behan-Pelletier & Walter, detail of preanal organ. Scale bars: A, B, E = 25 µm; C, D = 20 µm.

FIGURES 10 – 11. Tegoribates americanus Hammer, adult female, legs removed; 10, ventral aspect; 11, lateral aspect of prodorsum and podosoma, gnathosoma removed, with arrow to taenidium. Scale bar = 50 µm.

FIGURES 17 – 18. Tegoribates bryophilus Woolley, adult female (non-type specimen), 17, dorsal aspect, 18, ventral aspect; legs not illustrated. Scale bar = 50 µm.

FIGURES 2 – 3. Protectoribates occidentalis sp. nov., adult female, legs not illustrated; 2, ventral aspect; 3, lateral aspect, only alveolus of seta ex illustrated, gnathosoma not illustrated. Scale bar = 50 µm.