Macrogena abbreviata, Ermilov, Sergey G. & Minor, Maria A., 2015

Ermilov, Sergey G. & Minor, Maria A., 2015, The oribatid mite genus Macrogena (Acari, Oribatida, Ceratozetidae), with description of two new species from New Zealand, ZooKeys 506, pp. 13-26 : 16-21

Taxon classification Animalia Oribatida Ceratozetidae

Macrogena abbreviata sp. n. Figs 23-25, 26-30, 31-34, 35-44

Diagnosis.

Body size: 254-291 × 143-151. Lamellar cusps without teeth. Translamella of medium thickness. Rostral setae setiform, ciliated. Lamellar and interlamellar setae of medium size, thickened, barbed. Bothridial setae fusiform. Three pairs of notogastral porose areas present. Notogastral setae short, thin. Monodactylous.

Description.

Measurements. Body length: 270 (holotype: female), 254-291 (six paratypes: three females, three males); notogaster width: 143 (holotype), 143-151 (six paratypes).

Integument. Body color light brown to brown. Body surface punctate (visible under high magnification). Lamellae and pedotecta I striate; epimeral region also with longitudinal striae, however it is visible only in dissected specimens.

Prodorsum. Medial ledge of rostrum truncated, lateral incisions well visible. Lamellae shorter than half of prodorsum. Lamellar cusps without teeth. Translamella straight, thickened. Rostral setae (24-28) setiform, ciliated. Lamellar (18-20) and interlamellar (32-36) setae thickened, usually indistinctly barbed (rarely with sparse, strong barbs). Bothridial setae (22-26) fusiform, with short stalk (6) and longer, indistinctly barbed head (16-20). Tutoria narrowly triangular distally, slightly rounded, sometimes pointed. Exobothridial setae (4) thin, smooth.

Notogaster. Anterior margin convex medially. Pteromorphs broadly rounded laterally. Porose areas Am elongate oval. Dorsophragmata of medium size. Three pairs of porose areas present, all rounded: Aa (6-8), A2 and A3 (4-6). Notogastral setae (12-14) thin, smooth. Lyrifissures distinct. Opisthonotal gland openings located posteriorly to im.

Gnathosoma. Subcapitulum longer than wide (65-69 × 45-53). Subcapitular setae thin, slightly barbed; m (18-20) longer than a (12-16) and h (8-10). Adoral setae (8) simple, densely barbed. Palps (45) with setation 0 –2–1–3– 9(+ω). Solenidion attached to eupathidium, both located on dorsal tubercle. Chelicerae (73-77) with two simple, barbed setae; cha (28) longer than chb (14-16). Trägårdh’s organ long, tapered.

Epimeral and lateral podosomal regions. Pedotecta I large, concave in dorsal view. Pedotecta II of medium size, triangular, rounded distally in ventral view. All pedotecta scale-like in lateral view. Genal teeth elongate narrowly triangular. Apodemes 1, 2, sejugal and 3 distinctly developed. Epimeral setal formula 3 –1–2– 2. Epimeral setae (8) thin, smooth. Custodia with long, pointed tips. Discidia triangular. Circumpedal carinae distinct.

Anogenital region. Genital (8-12), aggenital (8-12), anal (8-12) and adanal (12-14) setae thin, smooth. Lyrifissures iad located close to anal aperture, in inverse apoanal position. Ovipositor elongated (106-110 × 28), blades (45-49) shorter than length of distal section (beyond middle fold; 57-61). Each of three blades with four straight, smooth setae, ψ 1 ≈ τ 1 (24-28) longer than ψ 2 ≈ τa ≈ τb ≈ τc (12-16). Six coronal simple setae (8) present.

Legs. Monodactylous. Claws indistinctly serrate dorsally. Femora II with antero-ventral tooth (t). Formulae of leg setation and solenidia: I (1 –4–3–4– 18) [1 –2– 2], II (1 –5–3–4– 15) [1 –1– 2], III (2 –2–1–3– 15) [1 –1– 0], IV (1 –2–2–2– 12) [0 –1– 0]; homology of setae and solenidia as indicated in Table 2. Famulus (ε) short, blunted. Setae l’’ on genua I, II thick.

Material examined.

Holotype (female) and six paratypes (three females and three males): New Zealand, South Island, Central Otago, Old Man’s Range, 45°19'24"S, 169°12'28"E, 1655 m a.s.l., in the bare soil with some lichen outside of Dracophyllum muscoides cushion, 17 February 2014, collected by M. Minor.

Type deposition.

The holotype and two paratypes are deposited in the New Zealand National Arthropod Collection, Auckland, New Zealand; two paratypes are de posited in the collection of the Senckenberg Institution, Frankfurt, Germany; two paratypes are deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia.

Etymology.

The specific name abbreviata refers to the comparatively short interlamellar setae of this species.

Remarks.

Macrogena abbreviata sp. n. differs from all other species of this genus by the short interlamellar setae, which do not reach the lamellar cusps.