Epidamaeus olitor (Jacot, 1937)

Norton, Roy A. & Ermilov, Sergey G., 2021, Redescriptions of North American Epidamaeus (Acari, Oribatida, Damaeidae) species proposed by N. Banks, H. E. Ewing, A. P. Jacot, and J. W. Wilson, Zootaxa 5021 (1), pp. 1-65 : 44-49

Epidamaeus olitor (Jacot, 1937)

( Figs 22–24 )

Belba olitor Jacot, 1937a (p. 355)

Epidamaeus olitor (Jacot, 1937) ; Marshall et al. (1987, p. 142)

Damaeus (Epidamaeus) olitor (Jacot, 1937) ; Subías (2004, p. 79)

Diagnosis

Epidamaeus species with total length of adult 398–448. Cerotegument mostly with thick layer of filamentous excrescences; exuvial scalps usually present on notogaster. Prodorsum without propodolateral apophysis; Tubercle Ba present, Bp absent. Bothridial seta smooth, long, flagellate, with thin, highly flexible distal third; seta in similar in form but about 2/3 as long. Notogaster with spina adnata usually of medium size, relatively straight, variously tapered; setae of c -, l - and h -series acicular, slightly arched, radially directed, usually smooth. Parastigmatic enantiophysis dimorphic, with Sa relatively large, horn-like, Sp much shorter, conical; ventrosejugal enantiophysis with only tubercle Va; enantiophyses E2, M absent; discidium absent. Seta ad 3 well lateral to anal plate. Leg IV 1.1–1.2 times body length; femur IV shorter than trochanter IV (~1: 1.2).

Adult

Dimensions. Total length and maximum width, including seven cotypes (n = 4 females, 6 males) 385–441 × 249– 265; males usually smaller (398–415) than females (415–441).

Integument ( Fig. 23 ). Body color yellowish to medium brown. Cerotegument with mostly filamentous excrescences, forming thick, loose mat on legs (except distal part of tarsi) and in sejugal region; with long, loose filaments on exposed parts of notogaster and sejugal region; shorter, loose filaments on venter. Filaments or shorter excrescences usually covering most leg setae and solenidia, as well as prodorsal setae and notogastral setae p 1 – p 3; most other body setae usually with little or no cerotegument. Procuticle with general porosity but surface mostly smooth; microtubercles present locally: distinct on stalks of basal leg segments, moderately to weakly developed on anal plates, enantiophyses and other body tubercles. Usually with full stack of juvenile exuvial scalps, lacking adherent fecal pellets, eggshells, or other large debris ( Fig. 23A ).

Prodorsum ( Figs 22A, B , 23B, C ). Body wall anterior to acetabula I, II oblique, nearly flat in dorsal view; propodolateral apophysis absent; without strong contour anterior to bothridium. Postbothridial enantiophysis represented by well-developed, triangular tubercle Ba, usually with low ridge or strong contour in usual position of Bp; Da and laterosejugal enantiophysis absent. Sigillar patches of cheliceral and subcapitular muscles conspicuous in transmitted light (not illustrated). Setae le and ro similar in length (69–77) and thickness; finely attenuate, weakly barbed, curved anteromedially but with flexible tips. Seta in (118–156) long, subflagellate ( Fig. 23C ), fine, flexible tip often broken ( Fig. 23B ); with small barbs in proximal half; angled posterolaterad. Seta ex (49–53) thin, attenuate, weakly barbed, usually curved dorsad; vestige exv absent. Bothridium with external part funnel-shaped, with welldefined thickened vertical bands; mutual distance of pair twice that of tubercles Ba. Bothridial seta (159–228) usually smooth, flagellate, directed dorsolaterad, usually almost straight ( Fig. 23B ) except for fine, flexible tip; tip usually hidden in thick cerotegument but often broken.

Notogaster ( Figs 22A–C ; 23A, D–H ). Nearly circular in outline, about 1.1 times longer than broad; uniformly curved, hemispherical with maximum height in middle. Spina adnata of medium length (usually 25–30 but up to 40), usually barely reaching level of prodorsal tubercle Ba; usually narrowly triangular, rarely thicker, curved ( Fig. 23E ); pair relatively widespread, mutual distance ~ 0.4 times maximum notogastral width. Setae of c -, l - and h -series directed radially, inserted in shallow curve, with mutual distance of lyrifissure im ~ 1.7 times that of lm in dorsal view; pigmented (light grey to brown), acicular, slightly bowed ( Fig. 23H ), usually smooth or with inconspicuous, fine surface roughening (rarely with barbs proximally); usual length range (outliers in parentheses): c 1 61–69 (83), c 2 63–76 (83), la 5 4–67 (78), lm 51–66 (74), lp 49–66 (74), h 3 56–74, h 2 (54–74), h 1 47–56 (61). Setae of p -row slightly dimorphic: p 1 projecting posterolaterad, subflagellate (82–90), barbed proximally; p 2, p 3 curved laterad, attenuate, shorter (53–61) and slightly thinner, almost smooth. Seta c 3 rarely, aberrantly developed at base of spina adnata ( Fig. 23G ; see R21).

Coxisternum and lateral podosoma ( Figs 22B, D , 23I ). Tectum of podocephalic fossa normally developed, without lateral tooth-like projection. Without medial coxisternal pit on epimere I. Enantiophyses E2, M absent; tubercle Va large, triangular; Vp absent, often a strong, ridge-like contour in its place. Tubercles of parastigmatic enantiophysis dimorphic: Sa horn-like, slightly bowed; Sp short, conical, directed toward Sa. Epimeral setae attenuate, weakly barbed, setation: 3–1–3–4; approximate lengths 1a, 1c, 2a, 3a (20); 1b, 3b, 4a, 4b (28–32); 3c, 4c, 4d (41–45). Seta 3c slightly removed from Sp and acetabulum III. Discidium absent.

Anogenital region ( Fig. 22C, D ). Anal plate lacking longitudinal line or carina parallel to medial margin, such that usual narrow band not demarcated. Genital (anterior pair 24–28; others 20), aggenital (20–24), anal (36–45) and adanal (36–45) setae attenuate, weakly barbed. Adanal seta ad 3 well removed from anal aperture, with ad 1 – ad 3 forming oblique row directed toward acetabulum IV. Lyrifissure iad oriented diagonally, slightly removed from anal aperture; ian present, but minute, anterior to seta an 2.

Gnathosoma . Subcapitulum longer than wide (100–105 × 69–77). Subcapitular setae (a, 20; m, h, 28–32) attenuate, weakly barbed. Adoral setae (10) attenuate, thin, weakly barbed. Palps (82–86) with normal setation: 0– 2–1–3–9(+ω). Solenidion bacilliform, appressed to tarsal surface. Postpalpal seta (6) spiniform, smooth. Chelicera (92–102) typical of family; attenuate seta cha (28) barbed throughout, chb (20) barbed unilaterally in middle part.

Legs ( Fig. 23A , 24 ). Relative lengths (I to IV) 1.0: 0.8: 1.0: 1.2; leg IV 1.1–1.2 times body length. Femur IV shorter than trochanter IV (~1:1.2); approximate length of leg segments shown in Table 1. Proximal stalk of femur IV shorter than distal bulb (~1:1.2–1.6). Claw of each leg smooth, basal tooth absent. Formulas of leg setation and solenidia: I (1–7–4–4–20) [1–2–2], II (1–6–4–4–17) [1–1–2], III (2–4–3–3–17) [1–1–0], IV (1–4–3–3–14) [0–1–0]. Notably: all tarsi with proximal accessory pair (v) present, v 2 ʹ and v 2 ʺ absent; v 2 ʺ present on femur I, absent from II; seta vʺ absent from femur III. Setae d and l similar to other setae (thin, attenuate); seta d of genua I–III ~1.5–2.5 times longer than respective coupled solenidia. Solenidion φ 1 on tibia I and φ on tibia IV both flagellate (‘tactile’); other solenidia thin, blunt, isodiametric or slightly tapered (‘ceratiform’), curved to various degrees. Famulus of tarsus I acicular to acuminate, erect. Shapes and relative sizes of other setae shown in Fig. 20 .

upper right insert = same of different cotype); C—partial prodorsum of crushed slide-mounted specimen from New Hampshire

(anterior to left) showing dislodged but intact seta in (arrow on tip; * = dislodged notogastral seta); D—right tubercle Ba and spina adnata from cotype; E—unusual left spina adnata from New York specimen; F—typical left spina adnata from New York specimen; G—right spina adnata from New York specimen with seta c 3 aberrantly expressed; H—notogastral seta c 2 of cotype; I—left ventrosejugal region of cotype, ventral view. Scale bars 10 μm (D–I), 20 μm (B, C), 100 μm (A).

Juveniles

Unknown, except for exuvial scalps on adult notogaster ( Fig. 23A ). Scalps always appear compressed and damaged. Attachment cornicle k observable in only one specimen (instar not determinable): in form of spiral, similar to that of Metabelba papillipes (Nicolet, 1855) or Porobelba spinosa (Sellnick 1920) ( Ermilov 2012; his Figs 2.9 , 3.8 ).

Figures

FIGURE 2. Epidamaeus puritanicus (Banks, 1906), light photographs of adult: A—habitus, right lateral view; B—different individual, showing egg shells attached to exuvial scalps; C—sejugal region and proximal proterosoma, right lateral (slightly ventral) view (insert = alveolus of seta ex and vestige exv); D—partial proterosoma, dorsal view (legs represented by only trochanters); E—similar view, but posterolateral corner of two different individuals (arrow to weak propodolateral apophysis; F—bothridial and dorsosejugal region, lateral view (slightly ventral, anterior to right). Scale bars 20 μm (C–F), 100 μm (A, B).

FIGURE 3. Epidamaeus puritanicus (Banks, 1906), light photographs of adult (A–F) and tritonymph (G): A—notogaster,

FIGURE 20. Epidamaeus florida (Wilson, 1936), adult: A—right leg I, without trochanter, abaxial view; B—femur, genu and tibia of right leg II, abaxial view; C—femur, genu and tibia of right leg III right leg III, near dorsal view; D—left leg IV, without trochanter, abaxial view. Scale bar 50 μm.

FIGURE 22. Epidamaeus olitor (Jacot 1937), adult: A—dorsal view (legs not shown except trochanters I; strong curvature of seta bs is artifact of mounting, cf. Fig. 23 B); B—anterior half of body, right lateral view (gnathosoma and legs not shown); C—posterior part of body, right lateral view; D—ventral view (legs represented only by trochanters). Scale bar 100 μm.

FIGURE 23. Epidamaeus olitor (Jacot 1937), light photographs of adult: A—lateral habitus of specimen from New York; B—posterior prodorsum and anterior notogaster of cotype, dorsolateral view (seta in broken; left insert = enlarged tip of seta bs;

FIGURE 24. Epidamaeus olitor (Jacot 1937), adult: A—right leg I, except trochanter, abaxial view; B—femur, genu and tibia of right leg II, dorsoabaxial view; C—femur, genu and tibia of left leg III, abaxial view; D—left leg IV, except trochanter, abaxial view. Scale bar 50 μm.