Tegoribates walteri, Behan-Pelletier, 2017

Behan-Pelletier, Valerie M., 2017, Tegoribatidae of North America, with proposal of Protectoribates gen. nov., and new species (Acari, Oribatida, Tegoribatidae), Zootaxa 4337 (2) : 182-187

Tegoribates walteri sp. nov.

( Figs. 20 , 21 , 22A–D , 23 )

Material examined: Holotype: adult male, USA, California, Sonoma Co., Salt Point State Park , 38°567N 123°333W, Sea Cliff Trail , 6.iii.2009 (VBP and M. Behan) from litter under lupins; deposited in the CNC, type number 24350 . Paratypes: 2 females, 10 males with same data as holotype. Paratypes deposited in the CNC, USNM, and RNC.

Diagnosis. Total length 350–400. Lamella 104 long, medially with V-shaped indentation, about 3 long. Lamellar seta arising anteriorly on fused lamella, 10–17 long. Interlamellar setae 7–11. Bothridial seta fusiform, 77–90 long. Pedotectum I pointed distally. Muscle sigillae strongly developed on notogaster (clearly visible with incident illumination). Octotaxic system as 4 pairs porose areas, Aa about 11 in diameter. Notogastral setae smooth, 6–8, setae subequal in length; lm posteromedial of Aa and lp dorsocentrally positioned, medial of A1. Tutorium 72– 80 long, of which cusp 17–21. Custodium pointed distally, 3–5 long. Tridactylous.

Description. Adults. Dimensions: Total length: females (n = 2) 370, 400; males (n = 10) 359 (range 350–374). Notogastral width: females (n = 1) 240; males (n = 10) 230 (range 221–240).

Integument: Smooth; longitudinal shallow grooves ventrally extending from level of custodium to posterior of anal plate ( Fig. 21B ). Pteromorph, pedotectum I, gnathosoma , epimeres microtuberculate ( Figs. 21 C–E ).

Prodorsum: Seta ro about 25 long, strongly barbed along length, acuminate, curved anteromedially; mutual distance about 50 ( Fig. 21C ). Lamella about 104 long, medially with V-shaped indentation; about 3 long. Lamellar seta arising anteriorly on fused lamella, 10–17 long; mutual distance 26–28 ( Figs. 20 , 21C ). Seta in 7–11 long, thin, smooth, acuminate; mutual distance 53–56 ( Figs. 20 , 22A ). Bothridial seta fusiform, 77–90 long. Seta ex not evident, alveolus present. Dorsophragmata fused, elongated, length about 22 ( Fig. 22A ).

Lateral region of podosoma: Taenidium extending from rostrum to acetabulum I ( Fig. 21E ). Pedotectum I pointed distally. Tutorium narrow tectum, about 74 long, with tooth distally, about 3 long, covering insertion of seta ro. Custodium tapered to point distally 3–5 long ( Fig. 22C ).

Notogaster: Slightly longer than wide: 1.2:1; anterior margin straight. Lenticulus absent. Muscle sigillae clearly evident on anterior of notogaster with incident or transmitted illumination ( Fig. 22D ). Octotaxic system expressed as porose areas, Aa about 11 in diameter, A1–A3 about 9 at widest; porose area A3 variable, may be absent bilaterally (1 specimen) or unilaterally (1 specimen) ( Fig. 20 ). Notogastral setae smooth, 6–8 long, setae subequal in length; lm posteromedial of Aa and lp dorsocentrally positioned, medial of A1; mutual distance of h1-h1 about 90, of p1-p1 about 59.

Ventral Region: Epimeral setae mostly about 7–18 long, thin, smooth, acuminate, with 1c slightly barbed. Aggenital, anal and adanal setae smooth; genital setae about 14, others about 9. Genital setae six pairs, g1-g3 about 14 long, posterior 3 pairs about 9 long. Lyrifissure iad at anterolateral edge of anal plate. Postanal porose area about 33 long and 4 wide.

Gnathosoma: Small axillary saccule present at base of palp, 4 x 2. Length of seta m>a>h.

Legs: Setation as for Tegoribates americanus ( Figs. 12A–C , Table 3). Seta l” of genu II strongly spine-like ( Figs. 21A, C ). Tridactylous.

Immatures. Dimensions: Mean length (based on slide mounted specimens): protonymph (n=1) 260; deutonymph (n = 1) 360. Length of prodorsal and hysterosomal setae given in Table 1.

Larva ( Fig. 23A ). Only scalp available. Length scalp 159 (n =1). Setae c, da, dm, dp small, smooth, tapered; mutual distance da-da, dm-dm, dp-dp 12, 16 and 10, respectively.

Protonymph ( Fig. 23B ). Integument: Sclerotized with light brown coloration. All of body, other than centrodorsal region of hysterosoma covered by layer of cerotegument as globules, about 1 in diameter.

Prodorsum: Porose region on aspis not evident. Seta ro finely barbed along length, tapered. Seta le, in and ex smooth, isodiametric; mutual distance of setae ro-ro, le-le and in-in about 19, 20 and 34, respectively. Bothridial seta setiform.

Gastronotic Region: Integument without sclerotization; centrodorsal region normally covered by larval scalp, smooth; integument slightly plicate laterally. Gastronotal setae of c, d, p series and la, lm, h2, h1 short, smooth, isodiametric; lp and h3 long, setiform, embedded in thick covering of cerotegument. Mutual distance of setae dada, dm-dm and dp-dp about 12, 21 and 9, respectively.

Ventral Region: Medial margin of epimeral plates weakly defined. Epimere I with narrow mentotectum overlapping medially. Epimeral, genital, aggenital, anal and adanal setae smooth, isodiametric, about 9 long. Porose integument surrounding opening of opisthonotal gland not evident.

Gnathosoma: Axillary saccule present. Palpal eupathidium acm attached to solenidion along distal threequarters of solenidial length.

Legs: Genua and tibiae I-IV with seta d subequal in length to companion solenidion; solenidion on genua I-III and tibiae II, III with slightly bulbous tip.

Deutonymph ( Figs. 23 C, D ). As for protonymph, except for overall size. Dorsal of hysterosoma with few plicae. Length of combined larval and protonymphal scalps about 220. Mutual distance of ro-ro, le-le and in-in about 20, 17, and 42, respectively. Gastronotal setae c, d, l, p, and h1 short, isodiametric; setae h3 and h2 brush-like, broad, long; mutual distance of setae da-da, dm-dm and dp-dp about 12, 25 and 10, respectively.

Epimeral setae (protonymph and deutonymph): 3-1-2-1, 3-1-2-2. Genital, aggenital, anal and adanal setae (protonymph and deutonymph): 1-3, 1-1, 0-0, 0-2, respectively.

Leg setae and solenidia as for protonymph and deutonymph of Tegoribates americanus in Table 3.

Etymology. The specific epithet honours my colleague and friend Dr. David Evans Walter, who has contributed so significantly to acarology in North America and globally.

Remarks. Adults of Tegoribates walteri sp. nov., are clearly distinguished from those of other North American species of Tegoribates by having the octotaxic system in the form of porose areas; porose areas are also found in T. montana and T. natalensis , known from South Africa ( Engelbrecht 1986). The 2 South African species are monodactylous, whereas T. walteri sp. nov. is tridactylous.

Immatures of T. walteri sp. nov. and T. americanus are similar in the shape and length of setae c and d, but l and h series setae differ in shape and length ( Table 1). Comparisons with immatures of T. latirostris are limited, as only the illustrations of Tuxen (1943) are available. The larva he illustrated appears similar to that of T. americanus with long, thick setae h3 and h2.

Gut contents of immature and adult Tegoribates walteri sp. nov. include fungal hyphae and spores.

Figures

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 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.

FIGURE 23. Tegoribates walteri sp. nov., differential interference contrast microscope images of immatures; A, larval scalp (3 layers); B, protonymph (3 layers), dorsal aspect, larval scalp removed; C, larval and protonymphal scalp, with arrow to tubercle in region of setae dp; D, deutonymph, dorsal aspect, with scalps removed. Scale bars: A – C = 20 µm; D = 40 µm.