Gaeolaelaps andensis, 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 : 62-67

Gaeolaelaps andensis sp. nov.

( Figures 20–37 )

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 . Paratypes, ten females and three males same data as holotype (in ZSM & TSUMZ) .

Diagnosis (adult female). Dorsal shield reticulate throughout, parallel-sided from r3 to level of S2, progressively tapering until S5, until rounded posteriorly; with 38 pairs of smooth setae, 21 pairs of podonotal setae (z3 absent) and 17 pairs of opisthonotal setae, including two pairs of Zx setae, unpaired setae Jx absent. All setae relatively very short, length of setae decreasing from anterior to posterior. Shield with five pairs of discernible gland pores (gd1, 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), posterior margin almost straight but anterior margin slightly concave, remnants of gland pores gv1 apparent near posterior shield margin, ratio of shield length/width ≃ 0.88. Genital shield, with length/width ratio ≃ 2.4, with 7–8 cells posterior to inverted-V ridge. Anal shield with length/width ratio ≃ 1. Opisthosomal integument with eight pairs of smooth setae, peritremes relatively long, extending to level of s1 and slightly beyond acetabulum I. Fixed digit of chelicera with eight teeth, including an offset subapical tooth (gabelzhan). Tarsus IV with one (pd2) elongated setae, dorsal setae on femur IV slightly thickened and inserted on small tubercles.

Description. Female (n=11)

Dorsal idiosoma ( Figs 18 & 24 ). Dorsal shield 418–438 long, 209–220 wide, shield distinctly reticulate ( Figs 18 & 24 ). Shield parallel-sided from r3 to level of S2, progressively tapering until S5, until rounded posteriorly and with 38 pairs of smooth setae: 21 pairs of podonotal setae (16–21), z3 absent, 17 pairs of opisthonotal setae (11–17), including two pairs Zx setae. Lengths of setae decreasing from anterior to posterior and from central to lateral, j1 (14–16), z1 (9–12) and J5 (11–13) shortest, and Z5 (19–22) longest, see Figures 20 & 26 . Shield with about 21 pairs of discernible pore-like structures, including 16 poroids (id1, id2, id4–id6, idm -idm6, is1, idx, idl1, idl3, idl4) and five gland openings (gd1, gd5–6, gd8–9), others indistinct, see Figures 20 & 26 .

Ventral idiosoma ( Figs 21 , 27 & 28 ). Tritosternum with paired pilose laciniae (75–82), fused basally (3–5), columnar base 27–31 × 12–15 wide; presternal area lightly sclerotised, punctate, with a few transverse curved lines, sternal shield length 108–111, maximum width 125–128, narrowest between coxae II (78–81), with reticulate ornamentation throughout, except central and posterior parts smooth (or faintly reticulated) ( Figs 21 , 27 & 28 ), posterior margin almost straight but anterior margin slightly concave, remnants of gland pores gv1 apparent near posterior shield margin; bearing three pairs of smooth setae (st1–3) (24–27), never reaching base of next setae, one pair of lyrifissures (slit-like) adjacent to setae st1, and a pair of poroids (suboval) between st2 and st3. Metasternal setae st4 (21–23) 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 tongue-shaped, slightly expanded posteriorly, past setae st5, length 139–147, maximum width 54–60, posterior margin rounded, surface reticulated with irregular, mostly longitudinal lines in anterior region, posteriorly with 7–8 cells enclosed behind an inverted V-shaped ridge; bearing a pair of simple setae st5 (19–22) ( Figs 21 , 27 & 28 ). Shield flanked by two pairs of minute, elongate paragenital platelets; paragenital poroids iv5 located on soft cuticle lateral to shield near seta st5. Anal shield subtriangular, rounded anteriorly, length 62–68, width 64–68, anterior half lineate-reticulate, para-anal setae and post-anal seta subequal in length (17–20), cribrum consisting of a terminal tuft with 3–5 irregular rows of spicules and a pair of anterior arms reaching level of posterior margin of anus ( Fig. 21 ); anal gland pores (gv3) on anterolateral margin of anal shield. Soft opisthogastric cuticle with pair of oval metapodal plates (21–23 long × 4–6 wide), an additional small round metapodal platelet more medially and eight pairs of smooth setae (Jv1–Jv5, Zv1–Zv 2, Zv4) (19–27) and five pairs of poroids (four ivo & ivp). Exopodal platelets between coxae II–III subtriangular, elongate, narrow, those behind coxae III–IV and parapodal platelets contiguous, surrounding coxa IV, strip-like, extending narrowly behind coxae IV ( Fig. 21 ). Peritrematal shield well developed, bearing one gland pores (gd3) and one poroid (id3) at level near coxae II–III, poststigmatic extension of shield 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 relatively long, extending to level of s1 and slightly beyond acetabulum I.

Gnathosoma ( Figs 22–25 & 29–31 ). Epistome subtriangular and irregularly denticulate ( Figs 24 & 30 ). Hypostomal groove with six transverse rows of denticles, each row with 13–18 small denticles, with smooth anterior and posterior transverse lines, groove very slightly wider anteriorly. Hypostome with four pairs of smooth setae, h1 (25–27)> h3 (24–26)> pc (20–23)> h2 (17–19) ( Fig. 22 ). Corniculi robust and horn-like, extending slightly beyond palptrochanter. Supralabral process with three-tined apicoventral projection ( Fig. 23 ). Internal malae with one pair of fimbriate median projections, flanked by lobes with fimbriate anterior margin; labrum with pilose surface ( Fig. 22 ). Chaetotaxy of palps ( Fig. 29 ): trochanter 2, femur 5, genu 6, tibia 14, tarsus 15, all setae smooth; palpfemur with seta d3 thickened and al thickened; palpgenu with al1 stout, al2 thickened and apically club-shaped; palp tarsal apotele two-tined ( Fig. 29 ). Fixed digit of chelicera with an offset distal tooth (gabelzhan), 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 25 & 31 ).

Legs ( Figs 32–35 ). Legs II (295–305) and III (252–257) short, I (399–406) and IV (375–379) longer. Chaetotaxy normal for free-living Laelapidae : Leg I ( Fig. 32 ): coxa 0 0/1, 0/1 0, trochanter 1 0/1, 1/2 1 (pd1 slightly thickened), femur 2 3/1, 2/3 2 (all dorsal setae slightly thickened and pd1, pd2 inserted on small tubercles), genu 2 3/2, 3/1 2, tibia 2 3/2, 3/1 2. Leg II ( Fig. 33 ): coxa 0 0/1, 0/1 0, trochanter 1 0/2, 0/1 1 (al slightly thickened), femur 2 3/1, 2/2 1 (all dorsal setae slightly thickened and ad1, pd1 inserted on small tubercles, pd2 longer), genu 2 3/1, 2/1 2, tibia 2 2/1, 2/1 2 (all ventral setae slightly thickened). Leg III ( Fig. 34 ): coxa 0 0/1, 0/1 0, trochanter 1 1/1, 0/1 1 (ad slightly thickened and longer), femur 1 2/1, 1/0 1 (all dorsal setae slightly thickened), genu 2 2/1, 2/1 1, tibia: 2 1/1, 2/1 1 (av and al1 slightly thickened). Leg IV ( Fig. 35 ): coxa 0 0/1, 0/0 0, trochanter 1 0/2, 0/1 1, femur 1 2/1, 1/0 1 (all dorsal setae slightly thickened and inserted on small tubercles), genu 2 2/1, 3/0 1, tibia 2 1/1, 3/1 2 (pv thickened). Tarsi II IV with 18 setae (3 3/2, 3/2 3 + mv, md); with some thickened ventral and lateral setae, see Figures 33–35 . Tarsus IV with one noticeably long setae (pd2) (53–58), but ad2, al3, pd3 and mv barely longer than some tarsus IV setae. All pretarsi with well-developed paired claws, rounded pulvilli and normal ambulacral stalk.

Insemination structures. Not seen, apparently unsclerotised.

Description. Male (n=3) ( Figures 36 & 37 )

Dorsal idiosoma. Dorsal shield 316–323 long, 182–188 wide; ornamentation and chaetotaxy as in female.

Ventral idiosoma ( Fig. 36 ). Sternal, genital, endopodal, ventral and anal shields fused into holoventral shield, 261–268 long from anterior to posterior margins of shield, (68–73) wide at level of st2, (67–70) at st3 level and (139–147) at broadest point (behind parapodals), anterolateral edges of shield fused to endopodals between coxae I–II; shield reticulate throughout, except central part smooth (or faintly reticulated) (between st2 and st3), with five pairs of smooth sternal setae (st1–5), and three pairs of smooth ventral setae (Jv1, Zv1, Zv2) (15–18), plus three smooth circum-anal setae, post-anal seta (14–17) slightly shorter than para-anals (18–20), with five pairs of poroids and a pair of gland pore (gv3) on lateral margins of shield at anterior level of anal opening, iv1 slit-like; gland pore gv2 behind coxa IV not discerned; cribrum with 3–4 irregular rows of spicules, a pair of anterior arms reaching level of posterior margin of anus; metapodal platelets completely fused to shield ( Fig. 36 ). Soft opisthogastric cuticle with two pairs of simple setae, and three pairs of poroids. Peritremes and peritrematal shields similar to those in female.

Gnathosoma . Epistome and subcapitulum similar to female. Fixed digit of chelicera with five teeth of various sizes and slender pilus dentilis. Movable digit of chelicera unidentate, spermadactyl short and straight, with round tip, and free portion of spermatodactyl about half as long as movable digit ( Fig. 37 ); fringed hyaline arthrodial process at base of movable digit. Palps similar to those of female.

Legs. Chaetotaxy as in female.

Etymology. The specific name is derived from the name of the region (Andes Mountains) in which the type locality occurs.

Remarks. In most species of Gaeolaelaps the dorsal shield has 39 pairs of simple setae, including two pairs of Zx setae, the peritremes usually reach anteriorly to the level of coxae I (somewhere between level of setae s1 to z1). Setae z3 are occasionally absent, and sometimes the peritremes are slightly shorter, ending near to the level of s1 (as in G. andensis ) or even shorter, reaching to near the middle of coxae II or anterior level of coxa III (see Vatankhah et al., 2016). The most distinctive characters of G. andensis are dorsal shield bearing 38 pairs of very short setae (setae z3 absent) and peritremes extending to level of s1. The combination of these two characters is unusual in the genus and is shared with G. brevipellis ( Karg, 1979) which was described from Argentina. However, the new species can be easily distinguished from G. brevipellis by the following attributes: dorsal shield with 38 pairs of setae, including 21 pairs of podonotal setae, z3 absent (vs. dorsal shield with 37 pairs of setae, including 20 pairs of podonotal setae, both z3 and s4 absent in G. brevipellis ); (2) podonotal region setae longer than those of opisthonotal region of the dorsal shield (vs. dorsal shield setae subequal in length and much shorter in G. brevipellis ); (3) the distance between J3–J4 is nearly quadruple the length of J3 (vs. the distance between J3–J4 is nearly twice the length of J 3 in G. brevipellis ); (4) femur II in male lacks spine/spur-like setae (vs. femur II with somewhat spur-like and apically truncate seta in G. brevipellis ). Sheals (1962) described Hypoaspis patagoniensis and Hypoaspis reticulatus from Patogonia, Argentina, on the basis of one female specimen of each species collected from moss and lichen on rocks. Both species may be similar to G. andensis in having 38 pairs simple setae on dorsal shield but G. andensis can be easily distinguished from both described species by having much shorter dorsal setae. On the other hand, the correct generic placement of both described species by Sheals (1962) is unknown due to brief original descriptions which lacking the most important details, especially those concerning the shape of epistome and leg chaetotaxy. Overall, some other Gaeolaelaps species described from South America such as Gaeolaelaps analis ( Karg, 1982) , G. latopuga ( Karg, 2006) , G. tridentifera ( Karg, 1978) , G. praetarsalis ( Karg, 1978) may be similar to G. andensis in general appearance, but Gaeolaelaps andensis can be easily distinguished from these species and all other South American species of Gaeolaelaps (see Moreira, 2014; Marticorena et al., 2020) by the following combination of characters: (1) dorsal shield with 38 pairs of very short setae, including 21 pairs of podonotal setae, z3 absent, length of setae decreasing from anterior to posterior; (2) peritremes relatively long, extending to level of s1 and slightly beyond acetabulum I; (3) fixed digit of chelicera with eight teeth, including an offset subapical tooth (gabelzhan); (4) the distance between J3–J4 is nearly quadruple the length of J3; (5) the distance between J4–J5 is nearly twice the length of J4; (5) tarsus IV with only one noticeably long setae (pd2) and dorsal setae on femur IV slightly thickened and inserted on small tubercles. Recently Gwiazdowicz et al. (2020b) have recorded four species of Gaeolaelaps mites to the fauna of the United States for the first time and described two new species of this genus for science: G. klompeni and G. americanus based on morphological characters of adult females. Both species are similar to G. andensis in general appearance but in both species dorsal shield bearing 39 pairs of simple setae (22 pairs of podonotal setae and 17 pairs of opisthonotal setae). In the podonotal area, the number of setae in z -series is complete (z1–6) (vs. dorsal shield bearing 38 pairs of setae and z3 absent in G. andensis ), while in both respective figures (figure 1A, page 524 for G. klompeni and figure 4A, page 527 for G. americanus ), five pairs of z setae have been illustrated and setae z2 are incorrectly shown as missing in both species. Setae z2 were unintentionally omitted in illustrations of both species [personal communication with Alireza Nemati (February/2/ 2021)].

Figures

FIGURES 20–25. Gaeolaelaps andensis sp. nov., female. 20, dorsal idiosoma; 21, ventral idiosoma; 22, subcapitulum; 23, supralabral process; 24, epistome; 25, chelicera.

FIGURES 26–31. DIC micrographs of Gaeolaelaps andensis sp. nov., female. 26, idiosoma in dorsal view; 27, idiosoma in ventral view; 28, sternal & genital shields; 29, distal portion of palp, with a focus on apotele; 30, epistome; 31, chelicera.

FIGURES 32–35. Gaeolaelaps andensis sp. nov., female. 32, leg I (trochanter-tibia); 33, leg II; 34, leg III; 35, leg IV.

FIGURES 36–37. Gaeolaelaps andensis sp. nov., male. 36, holoventral shield; 37, chelicera.

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