Eutarsopolipus burwelli, Seeman, 2019

Seeman, Owen D., 2019, Two new species of Australian Eutarsopolipus (Acariformes: Podapolipidae) from Nurus medius (Coleoptera: Carabidae), Zootaxa 4647 (1), pp. 134-153 : 135-141

Eutarsopolipus burwelli sp. nov.

Diagnosis. All life stages: respiratory system absent; tarsus II without solenidion; femur I with three setae; genu I with two small, spine-like setae (l′, l′′ present), genua II–III with one seta (l′ present); claws present on legs I–III. Adult female: gnathosomal length 66–70, width 62–67, cheliceral stylets long, 75–95; idiosomal setae d 10–14, f 8–13, h 5–6; femur I seta l′ 2–4; genu I setae 2–3; tarsi II–III with seta pv′ absent. Larviform adult male: dorsal setae v1, sc1, sc2, c1, c2, d, f developed; leg setation same as female. Larval female: plates C and D separate; seta h2 short, 11–13.

Type material. 18 females, 5 males, 15 larvae, all ex Nurus medius , as follows. Australia: Queensland. Holotype female, Eungella NP, Mt William, Site 1, 1234 masl, 21.016°S 148.598°E, 14 Nov. 2013 , SC 25844, C. Burwell ( QMS 110124). Paratypes : 6 females, 3 larvae, same data as holotype ( QMS 110125 -33) ; 1 female, 1 male, Crediton SF, 28°18′28″S 148°32′33″E, 1 Dec–31 Dec 1993 , IN9787, ANZSES, HR# T110024 ( QMS 110134 -35) ; 7 females, 9 larvae, Eungella NP, Dalrymple Heights , 21° 8′12″S 148°29′30″E, IN7864, 6 Jan. 1973 , J. Hammond, HR# T82062 ( QMS 110136 -45; 1 female ZMH-A0002396, 1 larva ZMH-A0002398; 1 female ANIC 52-003930 , 1 larva ANIC 52-003931 ) ; 2 females, 1 male, Eungella NP, Upper Cattle Creek , 21°1′41″S 148°36′11″E, 17 Nov. 1992 , IN6186, G. Monteith, G. Thomson, H. Janetzki, HR# T82055 ( QMS 110146 -48) ; 1 female, 1 larva, Mount William , 21° 1′ 5″S 148°35′57″E, 21 Dec. 1992 – 10 Jan. 1993 , IN5952, ANZSES, HR# T82066 ( QMS 110149 -50) ; 3 males, 1 larva, Mt Macartney , 20°49′57″S 148°33′7″E, 19 Nov. 1992 – 15 Apr. 1993 , IN5936, HR# T82039 ( QMS 110151 -52; 1 male ANIC 52-003932 ; 1 male ZMH-A0002397) .

Type deposition. Holotype and most paratypes deposited in QM. One female, one male, one larva deposited in ANIC, one female, one male, one larva deposited in ZMH.

Description. Female ( Figs 1–3 , n = 18). Gnathosoma . Length 70 (66–70), width 67 (62–67). Palp length 16 (15–16). Cheliceral stylets 90 (75–95), pharynx width 21 (15–21), dorsal gnathosomal setae (ch) 36 (30–37), ventral setae (su) 18 (15–18), distance between ventral setae (su–su) 21 (18–23).

Idiosoma . Moderately physogastric, ovate. Length 325 (310–450), width 290 (270–370). Respiratory system absent. Prodorsal plate length 88 (83–99), with setae v1 13 (9–13), v2 vestigial, sc1 14 (12–15), sc2 95 (95–120); v2 anteromesad sc1. Distance between setae v1–v1 57 (52–58), sc1–sc1 108 (105–110), v1 –sc1 33 (28–34), v2–v2 68 (65–69), sc2–sc2 155 (125–155), sc1–sc2 42 (35–44). Plate C length 67 (63–70), setae c1 15 (15–17), setae c2 15 (11–16), distance between setae c1–c1 105 (88–110), c1–c2 88 (78–93); often with pair of pore-like structures laterad setae c1. Plate D length 64 (57–64), setae d 13 (10–14), d–d 165 (160–180), cupuli ia anteriad to anterolaterad setae d. Plate EF length 65 (60–65), setae f 13 (8–13), f–f 145 (130–145); cupuli im anteriad to anterolaterad setae f. Plate H length 30 (17–30), width 94 (94–115), setae h 5 (5–6). Venter: coxal setae short, usually simple (anomalous star-like form in holotype specimen), 1a 3 (2–3), 2a 5 (4–6), 3a 7 (6–7), 3b 6 (6–8). Alveoli 1b, 2b apparent. Distance between setae 1a–1a 40 (40–48), 2a–2a 58 (58–66).

Legs. Setal counts legs I–III, femur-tarsus: 3-2-6(+ φ)-9(+ ω), 0-1-4-7, 0-1-4-7. Leg I: femur I, d minute, l′ 4 (2–4), v′′ 17 (13–17); genu I, l′ 3 (2–3), l′′ 3 (2–3); tibia I, d 82 (70–82), l′ 6 (5–8), l′′ 11 (8–11), k 6 (4–6), v′ 8 (5–8), v′′ 10 (10–14), φ 10 (10); tarsus I, tc′ 17 (14–17), tc′′ 16 (15–17), pl′ 9 (8–11), pl′′ 16 (16–20), pv′ 3 (3), pv′′ 3 (4), s 7 (6–7), ω 3 (3), p′ 2 (2), u′′ 1 (1–2). Leg II: genu II, l′ 4 (3–4); tibia II, d 60 (50–60), l′ 8 (7–8), v′ 14 (12–15), v′′ 25 (23–29); tarsus II, tc′ 6 (5–6), tc′′ 65 (55–65), pl′ 3 (3), pv′′ 3 (3–4), u′ 8 (7–8), u′′ 1 (1–2), p′ 1 (1). Leg III: genu III, l′ 3 (3–4); tibia III, d 47 (45–50), l′ 7 (7–10), v′ 15 (10–15), v′′ 21 (17–26); tarsus III, tc′ 6 (5–6), tc′′ 60 (50–60), pl′ 3 (3–4), pv′′ 3 (3–4), u′ 8 (7–8), u′′ 1 (1), p′ 1 (1). Genu I, l′-l″ blunt, peg-like; tarsus I s spine–like. Tarsi II–III u′ spine-like, bifid, tc′, pv′, pv″ spine-like. Claws on legs I–III (1-2-2) well developed.

Larviform adult male ( Fig. 4 ; n = 5; square brackets indicate two male specimens with different measurements)

Gnathosoma . Length 30–33 [37–38], width 29–32 [34–35]. Palp length 10–14. Cheliceral stylets 22–26, pharynx width 6–9, ch 8–11 [13], su 6–9, su–su 13–14.

Idiosoma . Length 150–175, width 120–145. Prodorsal plate length 52–57 [59–63], width 86–97 [110–115], with setae v1 5–7, v2 vestigial, sc1 4–6, sc2 65–80; v2 anteromesad sc1. Distance between setae v1–v 1 22–26 [27–29], sc1–sc1 45–49 [52–57], v1 –sc 1 15–19 [20–21], v2–v 2 26–29 [30–34], sc2–sc2 53–63 [67], sc1–sc 2 20–22 [25–28]. Plate CD length 45–50 [58–65], width 105–115 [140–145], setae c1 4–7, c2 5–9, d 4–7; distance between setae c1–c1 38–45 [51–56], c1–c 2 28–33 [38–40], d–d 33–36 [44]; cupuli ia anterolaterad setae d. Plate EF bowed, posterior margin concave, length 24–28, width 40–43 [55–56], setae f 2–4, distance f–f 23–27 [35–37]; cupuli im anterolaterad setae f. Genital capsule length 18–26, width 27–28 [33–37], setae h minute. Venter: coxal setae 1a 2–3, 2a 3–4, 3a 3–5, 3b 4–5, alveoli 1b, 2b apparent. Distance between setae 1a–1a 21–24, 2a–2a 23–25 [28–36].

Legs. Setal counts legs I–III same as female; setal form similar. Leg I: femur I, d minute, l′ 2, v′′ 5–6; genu I, l′, l′′ 1–2; tibia I, d 40–45, l′ 2 [3–4], l′′ 3–4, v′ 2–3, v′′ 7–9, φ 7 [9–10], k 2–3; tarsus I, tc′ 12–14, tc′′ 13–14, pl′ 5–7, pl′′ 13–14, pv′ 1–2, pv′′ 1–2, s 4, p′ 1, u′′ 1, ω 2. Leg II: genu II, l′ 2–3; tibia II, d 25–27, l′ 5–8, v′ 10–14, v′′ 15–17; tarsus II, tc′ 3–5, tc′′ 24–26, pl′ 2–3, pv′′ 1–3, u′ 4–5, u′′ 1. Leg III: genu III, l′ 2; tibia III, d 18–20, l′ 5–6, v′ 8–11, v′′ 14–15; tarsus III, tc′ 3–4, tc′′ 25–27, pl′ 2–3, pv′′ 2–3, u′ 4–6, u′′ 1.

Larval female ( Fig. 5 ; n = 15). Gnathosoma . Length 55–61, width 52–56. Palp length 15–16. Cheliceral stylets 65–80, pharynx width 12–15, ch 30–38, su 8–12, su–su 15–20.

Idiosoma . Length 225–280, width 170–245. Prodorsal plate length 76–87, width 135–160, with setae v1 8– 11, v2 vestigial, sc 1 7–10, sc2 130–140; v2 anterolaterad sc1. Distance between setae v1–v1 35 –40, sc1–sc1 72– 78, v1 –sc 1 23–27, v2–v2 44 –47, sc2–sc2 86–98, sc1–sc2 35–45. Plate C length 57–58, setae c 1 12–17, setae c 2 8–12; often with pair of pore-like structures laterad setae c1. Plate D length 48–50, width 105–120, setae d 8–11, distance between setae c1–c1 56–68, c1–c2 47–57, d–d 67–77; cupuli ia anterolateral setae d, distance ia–d 2–4. Plate EF length 40–47, width 85–100, setae f 9–11, distance f–f 54–61; cupuli im anteriad setae f, distance im–f 4–5. Plate H length 29–36, width 21–23, seta h1 long, ca. 180, seta h2 short, 11–13. Venter: coxal setae all short, 1a 3–4, 2a 4–5, 3a 4–6, 3b 6–7. Distance between setae 1a–1a 28–31, 2a–2a 35–39.

Legs. Setal counts legs I–III same as adult female; setal form similar. Leg I: femur I, d minute, l′ 2–3, v′′ 10–12; genu I, l′ 2, l′′ 2–3; tibia I, d 75–85, l′ 11–13, l′′ 12–15, v′ 4–5, v′′ 12–15, φ 10–12, k 4–5; tarsus I, tc′ 15–17, tc′′ 15–18, pl′ 7–8, pl′′ 19–24, pv′ 1–2, pv′′ 1–2, s 5–6, p′ minute, u′′ 1–2, ω 2–3. Leg II: genu II, l′ 1–3; tibia II, d 40–45, l′ 8–9, v′ 14–15, v′′ 19–21; tarsus II, tc′ 3–5, tc′′ 25–36, pl′ 2–4, pv″ 2–3, u′ 5–6, u′′ 1. Leg III: genu III, l′ 2–3; tibia III, d 45–50, l′ 7–8, v′ 15–17, v′′ 16–20; tarsus III, tc′ 3–5, tc′′ 25–35, pl′ 2–4, pv′′ 1–2, u′ 5–6, u′′ minute–1.

Etymology. It is with pleasure that I name this species for my colleague Dr Chris Burwell, the collector of several host beetles for Australian mites, including this species.

Differential diagnosis. Eutarsopolipus burwelli is a member of the ochoai species group ( Husband 1995; Constantine and Seeman 2005). Within this group, this species is very similar to E. rutherfordae in having females with a reduced plate H, females and males lacking setae pv′ and tiny, spine-like genual setae l′ and l″. Females and larvae of each species are easily distinguished, but males and larvae are almost identical. Females are most easily separated by the size of the gnathosoma (66–70 × 62–67 in E. burwelli versus 53 × 53 in E. rutherfordae ), cheliceral stylets (75–95 in E. burwelli versus 60 in E. rutherfordae ), size of setae d and f (8–14 in E. burwelli versus 22–25 in E. rutherfordae ), and the size of tibia I seta l′ (5–8 in E. burwelli versus 13 in E. rutherfordae ). The larger gnathosoma of E. burwelli also presents in the larva (55–61 × 52–56 in E. burwelli versus 47 × 47 in E. rutherfordae ), as do the longer cheliceral stylets (65–80 in E. burwelli versus 48 in E. rutherfordae ).

Remarks. Two males had several measurements somewhat larger than the other specimens. Although these seem different, size variation in male podapolipid mites is a known phenomenon and extreme variation was recorded for Eutarsopolipus pungens Husband and Dastych, 1998 . This variation makes diagnostics based on males difficult. Similar variation in larvae and females has not been reported.

Constantine and Seeman (2014) described three new species of Eutarsopolipus that they placed in the ochoai species group. This decision was based on the original definition of the ochoai species group ( Husband 1995) and the key to species groups in Husband and Husband (2009). Since Husband (1995), the ochoai species group has obtained nine members as defined by Constantine and Seeman (2014), but its definition has become less robust and overlaps with the brettae species group, as proposed by Husband (2002).

Species in the ochoai group may lack a respiratory system ( E. earnshawi , E. lambkinae , E. rutherfordae ; E. scariteus Husband, 2001 ; E. weatherbyi Husband and Psalmonds, 2004 ), show only the rudiments of stigmata ( E. ochoai Husband, 1995 ), or have a well-developed respiratory system ( E. dastychi Husband & Khaustov 2004 ; E. leytei Husband & Corpuz-Raros, 1995 ). Species of the brettae species group, which comprises only E. brettae Husband, 2002 and E. obrieni Husband and Husband, 2015 , both lack a respiratory system. All these species retain claws on legs I–III, three setae on femur I, and at least one seta on genua I–III.

The presence/absence of a respiratory system is an important character in Eutarsopolipus . Several species groups are defined by this feature, as shown in the key of Husband and Husband (2009), which has an error in its first couplet (the first couplet needs to be reversed). Therefore, it is unhelpful if this character is not used consistently to define species groups. For instance, E. scariteus —a member of the ochoai species group—will key to the brettae species group in Husband and Husband (2009). Furthermore, the rudimentary stigmata of E. ochoa need to be reassessed as they occur in an atypical position at the anterior margin of the prodorsal shield (and posteromesad the gnathosoma ), so these may be another structure, as the stigmata are usually posterolaterad the gnathosoma in Eutarsopolipus .

A reformation of species groups based on phylogenetic analysis is needed, but in the interim it would seem best to define the ochoai species group in the manner originally intended, so that it includes only species with the respiratory system absent, retaining setae on all genua, and possessing claws on all legs. This definition includes the two species from the brettae species group ( E. brettae , E. obrieni ) but excludes E. dastychi and E. leytei . The latter two species could be accommodated in the leytei species group, defined by the retention of a respiratory system, presence of claws on all legs, three femur I setae and presence of setae on all genua. Within the ochoai and leytei species groups, some reductions are apparent. Some species lack setae l″ on genu I ( E. brettae , E. lambkinae , E. obrieni ) and males of some species have hypotrichous leg setation ( E. brettae , E. dastychi , E. lambkinae , E. ochoai , E. scariteus ). While the former character is homoplasious, the latter is found only in members of the ochoai and leytei species groups, and in the unusual species Eutarsopolipus stammeri Regenfuss, 1968 , which has its own species group.

Figures

FIGURE 1. Eutarsopolipus burwelli sp. nov., adult female, dorsum.

FIGURE 2. Eutarsopolipus burwelli sp. nov., adult female: (A) venter; (B) setae 1a, holotype specimen (anomalous form), detail; (C) setae 1a, paratype specimen (typical form), detail.

FIGURE 3. Eutarsopolipus burwelli sp. nov., adult female: (A) leg I, dorsal view; (B) leg II, dorsal view; (C) leg III, dorsal view; (D) tarsus III, ventral view.

FIGURE 4. Eutarsopolipus burwelli sp. nov., larviform adult male, dorsum.

FIGURE 5. Eutarsopolipus burwelli sp. nov., larval female, dorsum.