Eutarsopolipus ampullaceous, Seeman & Katlav, 2024

Seeman, Owen D. & Katlav, Alihan, 2024, Podapolipid mites (Acari: Heterostigmata): key to genera, biogeographical history and description of four new Australian species of Eutarsopolipus, Zootaxa 5448 (3), pp. 301-347 : 315-324

Eutarsopolipus ampullaceous sp. nov.

( Figs 2–10 )

Diagnosis. All life stages: solenidion present on tarsus II, well developed. Female and larva: legs I–III femora 3-0-0; genua 1-1-1 (lacking l″ on genu I). Female: Plate H absent. Male: opisthonotal setae minute; leg setation reduced: femora 2-0-0 (lacking v″ on femur I); genua lacking setae; seta tc′ absent on tarsi II–III. Larva: seta h2 slightly thickened, stiff, length 16–23.

Type material. All ex Lecanomerus niger (Darlington). Holotype female ( QMS 117000 ). Lambs Head ( East End ), 17°01′46″S, 145°39′20″E, 29 Nov 1993, G. Monteith, H. Janetzki & D. Cook, HR# T22039 . Paratypes. 10 females, 1 male, 11 larvae, as follows: 1 female ( QMS 117001 ), 2 larvae ( QMS 117010-11 ), same data as holotype . 1 female ( QMS 117008 ), 1 male ( QMS 117009 ), Bellenden Ker, Summit TV Station , 17°15′53″S, 145°51′29″E, 30 Nov–2 Dec 1998, G. Monteith, P. Bouchard, D. Cook, HR# T69236 . 1 female ( QMS 117002 ), 1 larva ( QMS 117012 ), Lambs Head , 10 km W Edmonton, 17°01′ 23″S, 145°38′33″E, 8–9 Jan 1990, G. & S. Monteith, HR# T22022 . 3 females ( QMS 117006-7 , ANIC), 4 larvae ( QMS 117015-16 , ANIC), Mt Fisher, 7km SW Millaa Millaa, Kjellberg Rd , 17°32′34″S, 145°33′31″E, 27 Apr–29 Apr 1982, G. Monteith, D. Yeates & D. Cook, HR# T21973 . 4 females ( QMS 117003-5 , ZMH), 1 larva ( QMS 117014 ), same data as #T21973 except HR# T21975 ; 2 larvae ( QMS 117013 , ZMH), Massey Range , 7 km NW Centre Bellenden Ker, 17° 13′ 51″S 145° 48′ 13″E, 11–12 Oct 1991, G. Monteith, H. Janetzki & D. Cook, HR# T22036 . 1 larva ( QMS 117017 ), Millaa Millaa Falls , 17°29′53″S, 145°36′32″E, 12 Aug 1968, B. Cantrell, HR# T21949 . All in QM except 1 female and 1 larva in each of ANIC and ZMH.

Other material examined. 1 female ( QMS 117018 ), Bellenden Ker, Summit TV Station , 17°15′53″S, 145°51′29″E, 30 Nov–2 Dec 1998, G. Monteith, P. Bouchard, D. Cook, HR# T69236 . 1 female ( QMS 117019 ), Bellenden Ker, Cable Tower 3 (1000 m), 17°16′22″S, 145°52′16″ E, Earthwatch, QM, HR# T21965 .

Description. FEMALE ( Figs 2–4 ; n = 11). Gnathosoma . Length 70 (70–76), width 55 (51–61). Palp with minute dorsal femoral seta. Cheliceral stylets 72 (66–78), dorsal gnathosomal setae (ch) 44 (44–55), ventral setae (su) 33 (23–33).

Idiosoma ( Figs 2–3 ). Length 450 (320–700), width 340 (280–420), larger specimens moderately physogastric, body bulging conspicuously at plate C. Dorsum: prodorsal plate (PrS) with setae v1 27 (23–26), v2 alveolar remnant, sc1 32 (28–37), sc2 85 (65–85). Distance between setae v1–v1 47 (44–53), sc1–sc1 93 (71–93), v1–sc1 29 (24–36), v2–v2 79 (54–75), sc2–sc2 120 (110–130), sc1–sc2 24 (25–39); one specimen with asymmetrical expression of v2 and sc 1 in reversed position. Plate C setae c1 12 (11–15), setae c2 19 (15–22), distance between setae c1–c1 69 (69–71). Plate D setae d 13 (13–18), d–d 140 (115–145), cupuli ia anteromesad d. Plate EF setae f 16 (16–19), f–f 130 (100–135), cupuli im anteromesad f. Plate H absent. Plates usually smooth, one specimen (#8, ex T21975) with weak imbricate ornamentation. Venter ( Fig. 3A–B ): membranous cuticle extensive, coxisterna 1–2 weakly defined; apodemes 1, 2 and appr well defined, apodemes 2 almost reaching appr, sejugal apodeme absent, apodemes 3–4 weakly defined; coxal setae ( Fig. 3B ) slender, 1a 4 (4–5), 2a 5 (4–6), 3a 5 (4–6), 3b 5 (5–8). Alveoli of 1b, 2b present.

Legs ( Fig. 4 ). Setal counts legs I–III, femur-tarsus: 3-1-6(+ φ)-8(+ ω), 0-1-4-6(+ ω), 0-1-4-6. Leg I. Femur, d 1 (m–1), l′ minute (m–1), v″ 21 (17–18); genu, l′ minute (m); tibia, d 75 (55–64), l′ 2 (m– 2, 7 in specimen #5, 7 asymmetrically in specimen #4), l″ 2 (m‒2), v′ 9 (7–12, 4 in specimen #5), v″ 9 (8–13), k 6 (5–8), ϕ 7 (6–8) baculiform; tarsus, tc′ 16 (17–18), tc″ 16 (15–19), pl′ 15 (12–15), pl″ 23 (18–23), pv′ 2 (2–3), pv″ 3 (3), ω 6 (6–7) baculiform, s 6 (6–7), u′′ minute (m–1), p′ absent. Leg II. Genu, l′ 2 (2–3); tibia, d 52 (45–58), l′ 5 (5–7), v′ 17 (16– 18), v″ 36 (30–34); tarsus, tc′ 11 (9), tc ″ 5 (4–5), pl ″ 27 (23–28), pvʹ minute (m), pv″ 8 (7–8), ω 5 (5–6) digitiform, u′ 7 (7–9), u′′ minute. Leg III. Genu, l′ 1 (m–1); tibia, d 15 (11–13, 43 in specimen #3), l′ 3 (4–7), v′ 15 (8–15), v″ 30 (24–28); tarsus, tc′ 11 (10–12), tc ″ 5 (4–5), pl ″ 19 (19–25), u′ 7 (6–8), pvʹ minute (m), pv″ 8 (7–10), u′′ minute. Setae u′′ on tarsi II–III extremely small, often not visible.

Legs modified setae: tarsus I setae (pv), u″, tarsi II–III setae pv′ small, blunt, thorn-like; tarsus I seta s and tarsi II–III setae tcʺ and u′ thickened, large, spine-like (tips not bifid).

MALE ( Figs 5–7 ; n = 1). Gnathosoma . Length 40, width 39. Palp with minute dorsal tibial seta. Cheliceral stylets 30, ch 3, su 6.

Idiosoma ( Figs 5–6 ). Length 210, width 150. Dorsum: prodorsal plate with setae v1 1, v2 alveolar remnant, sc1 1, sc2 41. Distance between setae v1–v1 23, sc1–sc1 45, v1–sc1 15–20 (asymmetry in position), v2–v2 34, sc2–sc2 67, sc1–sc2 24–29 (asymmetry in position). Plate CD setae c1, c2, d vestigial, distance between setae c1–c1 46, c1–c2 29, d–d 41; cupuli ia anteriad or anterolaterad setae d. Plate EF with setae f vestigial, distance f–f 20; cupuli im anterolaterad setae f. Genital capsule length 35, width 41, setae h vestigial. Venter ( Fig. 6 ): apodemes 1, 2 and appr well defined, apodemes 2 reaching appr, sejugal apodeme absent, apodemes 3–4 well defined. Coxal setae ( Fig. 6B ) slender, 1a 2, 2a 3, 3a minute, 3b 5.

Legs ( Fig. 7 ). Setal counts legs I–III, femur-tarsus: 2-0-6(+φ)-8(+ω), 0-0-4-5(+ω), 0-0-4-5. Compared to female: lacking seta v″ on femur I, all genual setae, and tc′ on tarsi II–III. Leg I. Femur, d minute, l′ minute; tibia, d 35, l′ minute, l″ minute, v ′ 3, v ″ 12, k 6, φ 8 baculiform; tarsus, tc′ 12, tc″ 13, pl′ 7, pl″ 12, pv ′ 2, pv″ 2, ω 6 digitiform, s 5, u ′′ minute. Leg II. Tibia, d 21, l′ minute, v′ 10, v″ 15; tarsus, tc ″ 5, pl ″ 11, pvʹ 2, pv″ 3, ω 4 digitiform, u ′ 6. Leg III. Tibia, d minute, l′ 2, v′ 12, v″ 14; tarsus, tc ″ 5, pl ″ 13, pvʹ minute, pv″ minute, u ′ 5. Tibia I with tiny supernumerary seta expressed asymmetrically (denoted x on figure).

Modified setae: same as female except—tibia I seta l′ and v′ small, pointed, spine-like; tibiae II–III seta l′ small, blunt, peg-like; seta pv″ not spine-like.

LARVAL FEMALE ( Figs 8–10 ; n = 11). Gnathosoma . Length 50–55, width 39–48. Palp with minute dorsal tibial seta. Cheliceral stylets 55–65, ch 27–28, su 10–11.

Idiosoma ( Figs 8–9 ). Length 215–400, width 155–250; larger specimens swollen around plate C. Prodorsal plate with setae v1 18–24, v2 alveolar remnant, sc1 8–16, sc2 70–95. Distance between setae v1–v1 33–36, sc1–sc1 74–79, v1–sc1 26–33, v2–v2 57–60, sc2–sc2 82–91, sc1–sc2 32–37. Plates C and D fused medially (sometimes broken apart at C–D). Plate C setae c1 8–12, setae c2 11–15, distance between setae c1–c1 34–41. Plate D setae d 7–9, d–d 52–69, cupuli ia anteromesad d. Plate EF setae f 7–9, f–f 53–60, cupuli im anteriad f. Plate H poorly expressed, caudal cone 22–28 wide, 12–18 long, bearing setae h1> 70 (ca. 120 in some specimens), h2 16–23, stiff. Venter ( Fig. 9 ): membranous cuticle extensive, coxisterna 1–2 weakly defined; apodemes similar to female but all weakly defined. Coxal setae ( Fig. 9B ) slender, 1a 4–5, 2a 4–5, 3a 2–4, 3b 5–6. Alveoli of 1b, 2b not visible.

Legs ( Fig. 10 ). Setal counts legs I–III, femur-tarsus: 3-1-6(+ φ)-8(+ ω), 0-1-4-5(+ ω), 0-1-4-5 (setae pv′ absent on tarsi II–III). Leg I. Femur, d minute, l′ 2–3, v″ 10–15; genu, l′ 2–3; tibia, d 47–53, l′ 7–11, l″ 4–5, v′ 5–6, v″ 9–13, k 6–8, φ 6–8 baculiform; tarsus, tc′ 11–13, tc″ 13–14, pl′ 8–11, pl″ 14–15, pv′ 2, pv″ 3, ω 5–6 digitiform, s 5–6, u′′ minute, p′ absent. Leg II. Genu, l′ 2; tibia, d 26–33, l′ 6–7, v′ 9–13, v″ 18–22; tarsus, tc′ 7–9, tc ″ 4–5, pl ″ 14–16, pv″ 6–7, ω 4–5 digitiform, u′ 5–6, u′′ absent. Leg III. Genu, l′ 2; tibia, d 14–16, l′ 5–7, v′ 10–13, v″ 18–24; tarsus, tc′ 7–10, tc ″ 5–6, pl ″ 19–26, u′ 6–7, pv″ 5–6, u′′ absent. Legs I–III with two claws.

Modified setae: tarsus I seta s and tarsi II–III setae tc′ and u′ thickened, large, spine-like (tips not bifid); compared to female, several modified setae are slender instead.

Differential diagnosis. Eutarsopolipus ampullaceous sp. nov. is unique in Eutarsopolipus by the combination of having a solenidion on tarsus II, lacking seta l″ on genu I; females with an elongate gnathosoma (length 50–55, width 39–48) and without plate H; and larvae with strong setae h2. The loss of genual seta l″ was used to define the brettae species group, subsumed into the ochoai group by Seeman (2019a). This loss is present in E. brettae , E. divisus , E. lambkinae , E. obrieni , E. olszanowskii and E. ampullaceous sp. nov. The loss of ambulacral claws in E. divisus and E. olszanowskii immediately distinguish them from E. ampullaceous , and the presence of plate H distinguishes E. lambkinae from E. ampullaceous . Thus, the most similar species are E. brettae and E. obrieni found on different continents in the Neotropical region and from different host subfamilies. Eutarsopolipus ampullaceous differs from E. brettae by having females with a smaller, more elongate gnathosoma (70–76 × 51–61 versus 62–69 × 60–67 in E. brettae ) along with shorter cheliceral stylets (55–65 versus 85 in E. brettae ), and larvae with strong and longer setae h2 (16–23) versus thin and shorter setae in E. brettae (5–7). Eutarsopolipus ampullaceous differs from E. obrieni by retaining setae l′ on femur I (absent in E. obrieni ), retaining coxal setae 3a (absent in E. obrieni ), and having larvae with longer setae h2 (16–23 versus 5) and an almost fully separated or fully separated shield CD (almost fully fused C–D in E. obrieni ).

Etymology. The specific name ampullaceous (L., big-bellied) refers to the bulging plate C of adult females.

Remarks. Many specimens had large amounts of crystalline waste matter that obscured features of the opisthosoma. Later, more specimens were collected and these were cleared in 10% KOH until the crystalline matter dissolved; they were then soaked in ethanol and mounted in Hoyer’s medium.

Two non-type female specimens (ex T69236 , T21965 ) have their idiosomal plates with distinct imbricate ornamentation and may represent another species. These specimens have some longer opisthosomal setae (c1 20–22 versus 11–15; d 19–21 versus 13–18) and, on tibia III, seta d is long (ca. 35). However, one specimen (female #8, ex T21975 ) also expressed some weak imbrication, and another specimen (female #3, ex T69236 ) had a long seta d on tibia III (length 43). Therefore, these two females may be unusual variants, and are tentatively regarded under the same species. The single male specimen was found with the female with a long seta d (female #3) and a non-type female with imbricate patterning ( QMS 117018 ) (i.e. the same host individual, T69236 ). Thus, should the imbricate form later prove to be a separate species, then the male could belong to either species .

The loss of leg setae in males is commonly reported in the ochoai species group (e.g., Katlav et al. 2020; Seeman 2021). This is usually restricted to the femora and genua, yet the loss of seta tc′ on tarsi II–III is unique to E. ampullaceous . A further anomaly is the addition of seta pv′ on tarsi II–III in the male, which usually appears in the adult female only, although the recently described males of the leytei group species E. biuncatus and E. janus also possess this seta ( Seeman 2021). Also noteworthy is the variation in fusion of plates C–D in larvae. In smaller and presumably younger larvae these plates were fused medially, but the plates tended to be separate in larger, swollen and presumably older specimens.

Figures

FIGURE 2. Eutarsopolipus ampullaceous sp. nov. Female, dorsum. Membranous idiosomal cuticle is shaded grey.

FIGURE 3. Female Eutarsopolipus. (A) E. ampullaceous sp. nov. venter, showing apodemes and (B) coxal setae; (C) E. tripodus, coxal setae; (D) E. vepreculus, coxal setae; (E) E. walteri, coxal setae. Membranous idiosomal cuticle is shaded grey.

FIGURE 4. Eutarsopolipus ampullaceous sp. nov. Female, legs I–III (A–C). Tarsi II–III with minute seta u″ present but obscured.

FIGURE 5. Eutarsopolipus ampullaceous sp. nov. Male, dorsum. Membranous idiosomal cuticle is shaded grey.

FIGURE 6. Male Eutarsopolipus. (A) E. ampullaceous sp. nov. venter, showing apodemes and (B) coxal setae; (C) E. tripodus, coxal setae; (D) E. vepreculus, coxal setae; (E) E. walteri, coxal setae. Membranous idiosomal cuticle is shaded grey.

FIGURE 7. Eutarsopolipus ampullaceous sp. nov. Male, legs I–III (A–C). Femur I with asymmetrical supernumerary seta (x); tarsi II–III with minute seta u″ present on tarsi II–III.

FIGURE 8. Eutarsopolipus ampullaceous sp. nov. Larva, dorsum.

FIGURE 9. Larval Eutarsopolipus.(A) E. ampullaceous sp. nov. venter, showing apodemes and (B) coxal setae; (C) E.tripodus, coxal setae; (D) E. vepreculus, coxal setae; (E) E. walteri, coxal setae. Membranous idiosomal cuticle is shaded grey.

FIGURE 10. Eutarsopolipus ampullaceous sp. nov. Larva, legs I–III (A–C).