Gaeolaelaps acanthopedus, Joharchi & Friedrich, 2021

Joharchi, Omid & Friedrich, Stefan, 2021, Two new species of Gaeolaelaps Evans & Till (Acari: Laelapidae) from the Andes Mountains, Peru, Zootaxa 4995 (1), pp. 56-70 : 57-62

Gaeolaelaps acanthopedus sp. nov.

( Figures 3–19 )

Type material: Holotype, female, Monte Potrero , W of Molino, Departamento de Huánuco, Peru, South America, 09°54’30’’S 76°03’48’’W, 15–17 April 2016, alt. 2850–3100 m, leg. local collectors, from soil-litter (in MUSM) . Paratypes, seven females same data as holotype (in ZSM and TSUMZ) .

Diagnosis (adult female). Dorsal shield with reticulation, more distinct in opisthonotal and lateral regions, with 39 pairs of smooth setae, 22 pairs of podonotal setae and 17 pairs of opisthonotal setae, including two pairs of Zx setae and two unpaired setae Jx between J2 and J3, length of setae decreasing from anterior to posterior, j1 longest and Z5 shorter than j1, shield with six pairs of discernible gland pores (gd1–2, gd5–6, gd8–9). Presternal area lightly sclerotised, punctate, with a few transverse curved lines, sternal shield with reticulate ornamentation throughout, except central and posterior parts smooth (or faintly reticulated), anterior margin almost straight but posterior margin slightly concave, remnants of gland pores gv1 apparent near posterior shield margin, ratio of shield length/width ≃ 0.79. Genital shield flask-shaped, elongated and widened posteriorly behind setae st5, surface reticulated with irregular, mostly longitudinal lines in anterior region, posteriorly comprising 7–8 elongated oblique irregular cells enclosed behind an inverted V-shaped ridge, anterior margin of shield convex, overlapping posterior area of sternal shield, extending at level of poroids iv2, with length/width ratio ≃ 2.2. Anal shield pear-shaped, slightly wider than long, with length/width ratio ≃ 0.96, anal opening positioned somewhat centrally on the shield; cribrum extending anterolaterally slightly beyond postanal seta. Peritremes long, extending anteriorly to mid-level of coxae I. Soft opisthogastric cuticle with 10 pairs of setae. Internal malae fringed, with two pairs of projections. Supralabral process with a very long apicoventral projection. Fixed digit of chelicera with eight teeth, including an offset subapical tooth (gabelzahn). Most leg setae on tarsi II–IV spine-like (strongly thickened and apically tapered), ventral setae on tibiae II–IV, genua II–IV and setae ad, pl on trochanter IV spur-like (strongly thickened and apically blunt).

Description. Female (n=8)

Dorsal idiosoma ( Figs 3 & 9 ). Dorsal shield suboval, large, 674–702 long, 390–396 wide, covering most of dorsal idiosoma; reticulate throughout, more distinct in opisthonotal and lateral regions ( Figs 3 & 9 ). Shield bearing 39 pairs of smooth setae, 22 pairs of podonotal setae (34–51) and 17 pairs of opisthonotal setae (25–36), including two pairs of Zx setae and two unpaired setae Jx between J2 and J3, lengths of setae decreasing from anterior to posterior and from central to lateral, j1 (37–39) longest and z1 (17–21) shortest, J5 also short (24–26) and Z5 (30–32) shorter than j1. Shield with about 22 pairs of discernible pore-like structures, including 16 poroids (id1, id2, id4–id6, idm - idm6, is1, idx, idl1, idl3, idl4) and six gland openings (gd1–2, gd5–6, gd8–9), others indistinct, see Figures 3 & 9 .

Ventral idiosoma ( Figs 4 , 10 & 11 ). Tritosternum with paired pilose laciniae (98–110), fused basally (10–15), columnar base 41–43 × 18–20 wide; presternal area lightly punctate, with transverse curved lines; sternal shield length 163–167, maximum width 204–211, narrowest between coxae II (125–128), with reticulate ornamentation throughout, except central and posterior parts smooth (or faintly reticulated), anterior margin almost straight, posterior margin slightly concave; bearing three pairs of smooth setae (st1 54–57, st2 54–57, st3 49–51), st2 reaching to base of st3, and two pairs of slit-like poroids (lyrifissures), a pair of lyrifissures (iv1) adjacent to setae st1, and another pair of lyrifissures (iv2) between st2 and st3; remnants of gland pores gv1 apparent near posterior shield margin. Metasternal setae st4 (37–40) and metasternal poroids located on soft integument; metasternal platelets absent. Endopodal plates between coxae I–II (bearing gland pores gvb) and II–III completely fused to sternal shield, endopodal plates III/IV elongate, narrow and curved. Genital shield flask-shaped, elongate and widened posteriorly behind setae st5, length 322–330, maximum width 143–149, anterior margin of shield convex, overlapping posterior area of sternal shield, extending at level of poroids iv2, posterior margin rounded, surface reticulated with irregular, mostly longitudinal lines in anterior region, posteriorly comprising 7–8 elongated oblique irregular cells enclosed behind an inverted V-shaped ridge ( Figs 4 & 11 ). Paragenital poroids iv5 located on soft cuticle lateral to shield near seta st5. Anal shield pear-shaped, rounded anteriorly, length 84–93, width 93–96, anterior half lineate-reticulate, para-anal setae (27–30) longer than post-anal seta (22–25), cribrum with 3–4 irregular rows of spicules and a pair of anterior arms extending slightly beyond postanal seta ( Figs 4 & 11 ); anal gland pores (gv3) on anterolateral margin of anal shield. Primary (most lateral) metapodal platelets suboval (27–30 long × 13–10 wide), secondary and tertiary (18–22 long × 5–8 wide) more median, smaller, oriented obliquely. Soft opisthogastric cuticle with ten pairs of smooth setae (Jv1–Jv5, Zv1–Zv4 & R) [Jv1–Jv3 & Zv1–Zv2 (29–35), Jv4–Jv5 & Zv4–Zv5 (23–26)], and four pairs of poroids (three ivo & ivp). Exopodal platelets between coxae II–III subtriangular, elongate, narrow and curved, those behind coxae III–IV and parapodal platelets fused, surrounding coxa IV, gland pores gv2 on parapodal platelets ( Fig. 4 ). Peritrematal shield well developed, bearing one gland pores (gd3) and one poroid (id3) at level near coxae II–III, poststigmatic extension of shield more or less wide, with two pairs of poroids (id7 & ip) and one pair of gland pores (gp); anterior region of peritrematal shield fused to anterior margin of dorsal shield behind setae z1. Peritremes long, extending to mid-level of coxae I.

Gnathosoma ( Figs 5–8 , 12, 13 & 15 ). Epistome subtriangular and irregularly denticulate ( Figs 7 & 13 ). Hypostomal groove with six transverse rows of denticles, each row with 7–15 small denticles, with smooth anterior and posterior transverse lines, groove very slightly wider anteriorly. Hypostome with four pairs of smooth setae, h3 (55–53)> h1 (50–53)> pc (37–39)> h2 (32–34) ( Fig. 5 ). Corniculi robust and horn-like, extending slightly beyond palp trochanter. Supralabral process with a very long apicoventral projection ( Fig. 6 ). Internal malae with one pair of fimbriate median projections, flanked by lobes with fimbriate anterior margin; labrum with pilose surface ( Fig. 5 ). Chaetotaxy of palps ( Fig. 14 ): trochanter 2, femur 5, genu 6, tibia 14, tarsus 15, all setae smooth; palp femur with seta d3 thickened and al thickened; palp genu with al1 stout, al2 thickened and apically club-shaped; palp tarsal claw two-tined ( Fig. 12 ). Fixed digit of chelicera with an offset distal tooth (gabelzahn), followed by seven variously sized teeth, a setaceous pilus dentilis, dorsal cheliceral setae prostrate, arthrodial membrane with a rounded flap and normal filaments; cheliceral dorsal and lateral lyrifissures distinct; movable digit with two relatively large teeth ( Figs 8 & 15 ).

Legs ( Figs 16–19 ). Legs II (517–528) and III (494–503) short, I (640–664) and IV (741–768) longer. Chaetotaxy normal for free-living Laelapidae : Leg I ( Fig. 16 ): coxa 0 0/1, 0/1 0, trochanter 1 0/1, 1/2 1 (pv1 slightly thickened), femur 2 2/1, 3/3 2 (ad1 & pd1 pd3 thickened and inserted on small tubercles), genu 2 3/2, 3/1 2, tibia 2 3/2, 3/1 2. Leg II ( Fig. 17 ): coxa 0 0/1, 0/1 0, trochanter 1 0/2, 0/1 1 (al slightly thickened), femur 2 3/1, 2/2 1 (av & pd2 thickened and inserted on small tubercles), genu 2 3/1, 2/1 2 (av thickened and inserted on small tubercles), tibia 2 2/1, 2/1 2 (all ventral setae spur-like). Leg III ( Fig. 18 ): coxa 0 0/1, 0/1 0, trochanter 1 1/1, 0/1 1 (ad slightly thickened), femur 1 2/1, 1/0 1, genu 2 2/1, 2/1 1 (all ventral setae spur-like, ad1 & pd1 inserted on small tubercles), tibia: 2 1/1, 2/1 1 (all ventral setae spur-like, pd2 inserted on small tubercles). Leg IV ( Fig. 19 ): coxa 0 0/1, 0/0 0, trochanter 1 1/1, 0/1 1 (ad & pl spur-like), femur 1 2/1, 1/0 1 (ad1, ad2 and pd thickened & ad1, ad2 on small tubercles), genu 2 2/1, 3/0 1 (av spur-like), tibia 2 1/1, 3/1 2 (av, pv & pl1 spur-like). Tarsi II–IV with 18 setae (3 3/2, 3/2 3 + mv, md); most setae spine-like, see Figures 17 19 . All pretarsi with well-developed paired claws, rounded pulvilli and normal ambulacral stalk.

Insemination structures ( Fig. 14 ). Laelapid-type sperm access system, tubulus long, wider at the solenostome level of coxa III and entering sacculus via a pair of circular openings. Sacculus irregular, the proximal ends of the tubulus slightly swollen at junction with ramus.

Etymology. The name acanthopedus (Latin Acantho, spur + ped, foot) refers to the spur/spine-like appearance of some leg setae.

Remarks. The new species resembles G. loksai ( Karg, 2000) , G. cerata ( Karg, 1982) and G. circularis Hyatt, 1964 described from Ecuador and Venezuela (South America), respectively, in having similarly shaped and reticulated genital shield, the similar length of dorsal shield setae and body size. In both G. loksai and G. cerata the peritremes short, reaching to the mid-level of coxae II, while in G. acanthopedus the peritremes are long, extending to the mid-level of coxae I. Gaeolaelaps acanthopedus most resembles G. circularis (redescribed by Marticorena et al., 2020), due to its similarly shaped and reticulated genital shield and spine like setae on different segments of legs (especially those on tarsi II–IV). Gaeolaelaps acanthopedus differs from G. circularis by having 39 pairs of dorsal setae and much larger body size (674–702 long, 390–396 wide), while in G. circularis the dorsal shield has 33 pairs of setae and smaller body size (see Marticorena et al., 2020). Gaeolaelaps acanthopedus can easily be distinguished from all other South American species of Gaeolaelaps (see Moreira, 2014; Marticorena et al., 2020) by the following combination of characters: (1) most leg setae on tarsi II–IV spine-like (strongly thickened and apically tapered), ventral setae on tibiae II–IV, genua II–IV and setae ad, pl on trochanter IV spur-like (strongly thickened and apically blunt); (2) genital shield flask-shaped, elongated (anterior margin of shield extending at level of poroids iv2; (3) j1 longest dorsal setae and Z5 shorter than j1 (vs. Z5 longest dorsal setae in both G. cerata and G. loksai ); and (4) peritremes long, extending anteriorly to mid-level of coxae I (vs. in both G. cerata and G. loksai peritremes short, reaches to middle of coxa II); (5) tarsus IV without elongated setae; (6) fixed digit of chelicera with eight teeth; (7) palp tarsal apotele two-tined; (8) sternal shield poroid (iv2), slit-like (lyrifissures); and (9) supralabral process with a very long apicoventral projection.

Figures

FIGURES 3–8. Gaeolaelaps acanthopedus sp. nov., female. 3, dorsal idiosoma; 4, ventral idiosoma; 5, subcapitulum; 6, supralabral process; 7, epistome; 8, chelicera.

FIGURES 9–15. DIC micrographs of Gaeolaelaps acanthopedus sp. nov., female. 9, idiosoma in dorsal view; 10, idiosoma in ventral view; 11, sternal, genital & anal shields; 12, palp, with a focus on apotele; 13, epistome; 14, insemination structures; 15, chelicera.

FIGURES 16–19. Gaeolaelaps acanthopedus sp. nov., female. 16, leg I (trochanter-tibia); 17, leg II; 18, leg III; 19, leg IV.