Austrophthiracarus cronadun, Liu & Zhang, 2013

LIU, DONG & ZHANG, ZHI-QIANG, 2013, Two new species of Austrophthiracarus (Acari: Oribatida: Phthiracaridae) from New Zealand, Zootaxa 3682 (2), pp. 385-391 : 386-388

Austrophthiracarus cronadun sp. nov.

( Figs. 1–9 )

Material examined: Holotype: adult ( NZAC, in alcohol, 73/9), New Zealand: Capleston Bio. Res. Br., B.F.U.P., from litter, 12 Jan., 1973, leg. J. C. Watt 1 . Paratype: one adult ( NIGA, in alcohol, 73/9), same data as holotype .

Etymology. The new species is named after Cronadun—the small town closest to the type locality; it is used here as a noun in apposition.

Description. Measurements: Holotype: Prodorsum: length 270, width 228, height 102, setae: ss 35, ro 30, le 20, ex 25; notogaster: length 610, width 430, height 390; setae: c 1 175, ps 1 170, ps 2 150, ps 3 150, ps 4 50; ventral region: ad 1 130, ad 2 127, an 1 90, an 2 90; genitoaggenital plate 125×160, anoadanal plate 117×225. Paratype: Prodorsum: length 300, width 230, height 100; notogaster: length 593, width 425, height 380.

Integument. Colour yellowish. Surface of body punctate.

Prodorsum ( Figs. 1 ̅2). Median carina and lateral carinae absent; sigillar fields distinct, dorsal region longer than lateral regions; posterior furrows absent; sensilli (ss) short with narrow pedicel and broad head, covered with minute spines and truncate distally; interlamellar setae (in) vestigial; rostral setae (ro) spiniform, thin, short, rough and semi-erect; lamellar (le) and exobothridial setae (ex) short and fine; comparative lengths of setae: ss> ro> ex>le; mutual distance of setae: in ̅ in> ro ̅ ro.

Notogaster ( Fig. 1 ). 19 pairs of setae present, moderately long (c 1 / c 1 – d 1 =0.95), robust, covered with small spines in distal half, setae c 1 longest, setae ps 4 thinner and shortest; setae c 1–3 slightly far away from anterior border, setae c 2 more so than c 1 and c 3; four additional setae present (h 1 ’, ps 1 ’, ps 2 ’, ps 3 ’) with distribution as depicted in Fig. 1 ; vestigial setae f 1 not observed; two pairs of lyrifissures ia and im present.

Gnathosoma ( Figs. 5–7 ). Subcapitulum normal ( Fig. 5 ); setae h, m, and a simple and smooth; setae h shorter than distance between them; adoral seta or 1 apparently flat with barbs; or 2–3 simple and smooth; palp ( Fig. 6 ) four segmented, femur and genu fused; palpal setation: 0-2-2-7(1); supracoxal seta simple and smooth; chelicera ( Fig. 7 ) with two smooth setae (cha, chb).

Ano-genital region ( Figs. 1, 3–4 ). Nine pairs of genital setae (g) present, arranged in two rows with formula: 9(4+5): 0, their distribution as depicted in Fig. 3 ; one pair of aggenital setae (ag) present; anoadanal plates each with six setae, setae ad 1 and ad 2 rough, longer and thicker than other setae and anal setae (an), setae ad 1 longest, setae ad 3 and ad 3 ’ minute, similar in length to genital setae.

Legs ( Figs. 8–9 ). Setal counts for leg segments (excluding tarsi): I: 1-4-2(2)-5(1); II: 1-3-2(1)-3(1), III: 2-2- 1(1)-2(1), IV: 2-1-1-2(1); setae d on femora I inserted at level of setae v’’; setae a’’ on tarsi I and setae ft’’ on tarsi II curved distally; setae a’’ on tarsi II curved distally; setae s and pv’ on tarsi IV present; setae s on tarsi I and II absent; setae d on tibiae IV short, coupled with solenidia; all legs monodactylous.

Distribution. Known only from the type locality.

Remark. This new species is similar to Austrophthiracarus hallidayi Niedbała & Colloff, 1997 in the presence of narrow dorsal region of sigillar fields longer than lateral regions, lateral carinae absent, rostral and lamellar setae short, ro> le, in ̅ in> ro ̅ ro, 19 pairs of setae present, additional setae present in h and ps series, setae c 2 more far away from anterior border than c 1 and c 3, two pairs of lyrifissures present, genital setae arranged with similar formula, and setae d on femora I inserted at level of setae v’’, but can be easily distinguished from the latter species by the following nine characters (a versus b): in A. cronadun sp. nov., (1a) interlamellar setae vestigial; (2a) exobothridial setae present; (3a) head of sensilli much broader and truncate distally; (4a) distance between rostral setae longer; (5a) notogastral setae stronger and relatively shorter, c 1 / c 1 – d 1 <1; (6a) setae h 1 ’ situated between h 1 and ps 1; (7a) five setae inserted at the ps 2 level; (8a) setae h of mentum shorter than distance between them; (9a) setae ad 3 and ad 3 ’ minute, similar in length with genital setae. In A. hallidayi , (1b) interlamellar setae present; (2b) exobothridial setae vestigial; (3b) head of sensilli fusiform, narrow and slightly pointed distally; (4b) distance between rostral setae shorter; (5b) notogastral setae thinner and longer, c 1 / c 1 – d 1 =1.27; (6b) setae h 1 ’ situated between ps 1 and h 2; (7b) four setae inserted at the ps 2 level; (8b) setae h of mentum longer than distance between them; (9b) setae ad 3 and ad 3 ’ much longer than genital setae.

This new species is also similar to New Zealand species Austrophthiracarus pulchellus Niedbała, 1993 in the presence of vestigial interlamellar setae, but can be easily distinguished from the latter species by the following nine characters (a versus b): in A. cronadun sp. nov., (1a) dorsal region of sigillar fields longer than lateral regions; (2a) head of sensilli much broader and truncate distally; (3a) exobothridial setae present; (4a) notogaster with 19 pairs of setae; (5a) notogastral setae longer; (6a) setae g 7 situated postero-lateral of g 5; (7a) setae h of mentum present; (8a) setae ad 3 and ad 3 ’ minute, similar in length with genital setae; (9a) setae v’’ on femora I present; in A. pulchellus , (1b) dorsal region of sigillar fields similar in length with lateral regions; (2b) head of sensilli rounded, but not truncate distally; (3b) exobothridial setae vestigial; (4b) notogaster with 18 pairs of setae; (5b) notogastral setae much shorter; (6b) setae g 7 situated at the level of g 4; (7b) setae h of mentum vestigial; (8b) setae ad 3 and ad 3 ’ much longer than genital setae; (9b) setae v’’ on femora I absent.

Figures

FIGURES 1–9. Austrophthiracarus cronadun sp. nov.: 1, lateral view of body (legs removed); 2, prodorsum, dorsal view; 3, left side of genito-aggenital plate; 4, left side of anoadanal plate; 5, subcapitulum, palpi removed; 6, palp, antiaxial view; 7, chelicera, antiaxial view; 8, femur I; 9, tibia IV. Scale bars: 1, 2, 3, 4, 8, 9=100 µm; 5, 6, 7=50 µm.