Lanceoppia ( Bicristoppia ) archicostulata, Ermilov, 2016

Ermilov, S. G., 2016, New Oppiidae (Acari, Oribatida) from Chile, Acarologia 56 (4), pp. 505-516 : 506-510

Lanceoppia ( Bicristoppia) archicostulata n. sp.

( Figures 1-3)

Diagnosis — Body size: 233 – 241 × 131 – 143. Rostrum with median indentation. Costulae and transcostula present, arch-like. Interbothridial and postbothridial tubercles developed, rounded distally. Rostral setae setiform, barbed. Lamellar and interlamellar setae thin, erect, indistinctly barbed. Bothridial setae lanceolate, barbed. Notogastral setae c minute, other setae long, la and lm longest. Anogenital setae thin, setiform, smooth.

Description — Measurements – Very small species. Body length: 237 ( holotype, female), 233, 241 ( two paratypes: one female and one male); notogaster width: 135 ( holotype), 131, 143 ( two paratypes).

Integument — Body color light brownish. Body surface smooth, but lateral sides (between bothridia and pedotecta II and III) with tuberculate cerotegument (diameter of tubercles up to 2).

Prodorsum ( Figures 1A, 2A) — Rostrum with median, small, semioval indentation. Costulae (slightly shorter than half of prodorsum) and transcostula well developed, forming arch-like structure. Longitudinal rows, comprising several muscle sigillae, present in front of the bothridia. Interbothridial region with several (four to seven), indistinct muscle sigillae. Interbothridial ( tub i) and postbothridial ( tub p) tubercles strong, simple. Rostral setae ( ro, 18-20) setiform, barbed, inserted dorso-laterally, directed antero-medially. Lamellar ( le, 16) and interlamellar ( in, 8-10) setae thin, erect, indistinctly barbed; le inserted posterior to transcostula. Exobothridial setae ( ex, 4-6) minute, smooth, inserted on tubercles. Bothridial setae ( bs, 44-48) with long stalks and shorter, lanceolate, barbed heads.

Notogaster ( Figures 1A, 2A) — Anterior border convex medially. One pair of tubercles located anterior to border, directed to postbothridial tubercles. Ten pairs of notogastral setae: c minute (2), other long ( la, lm, 41 – 49; lp, h 1 - h 3, 24 – 26; p 1 - p 3, 16), setiform, smooth. Setae la inserted laterally to lm. Lyrifissures ia, im and ip and opisthonotal gland openings ( gla) well visible, lyrifissures ih and ips not visible.

Gnathosoma ( Figures 1B, 2A) — Subcapitulum longer than wide (53 – 57 × 41 – 43). Subcapitular setae ( a, m, h) similar in length (18 – 20), setiform, smooth. Palps (45) with setation 0-2-1-3- 8(+ω). Postpalpal setae (4) spiniform. Chelicerae (53 – 57) with two setiform, barbed setae; cha (20) longer than chb (12). Trägårdh’s organ tapered.

Epimeral and lateral podosomal regions ( Figures 1B, 2A) — Apodemes 4 semioval (forming a weak ridge in lateral view). Epimeral setal formula: 3-1-3-3; setae setiform, indistinctly barbed; 1c, 3c, 4a and 4c (20 – 24) longer than others (10 – 14). Pedotecta I represented by small laminae. Discidia ( dis) well developed, triangular, pointed distally.

Anogenital region ( Figures 1B, 2A) — Six pairs of genital ( g 1, 10-12; g 2 - g 6, 4 – 6), one pair of aggenital ( ag, 16 – 18), three pairs of adanal ( ad 1 - ad 3, 16 – 18) and two pairs of anal ( an 1, an 2, 12 – 14) setae setiform, smooth. Adanal lyrifissures ( iad) distinct, inverse apoanal.

Legs ( Figures 2 B-3) — Claw of each leg smooth. Trochanters III with one dorso-anterior tooth. Formulas of leg setation and solenidia: I (1-5-2-4-20) [1- 2-2], II (1-5-2-4-16) [1-1-2], III (2-3-1-3-15) [1-1-0], IV (1-2-2-3-12) [0-1-0]; homology of setae and solenidia indicated in Table 1. Setae p setiform on tarsi I, and very short, conical on tarsi II-IV. Solenidia ω 1 on tarsi I, ω 1 and ω 2 on tarsi II and σ on genua III thickened, blunt-ended, solenidia ’ on tibia II and III stick-like, erect, other solenidia setiform. Famuli () thickened, straight, inserted posteriorly to solenidia ω 1.

Material examined — Chile, vicinity of Punta Arenas, 53°38’02.8"S, 65°31’01.6"W, swamp, in Sphagnum magellanicum , 18.XI.2014 ( V. A. Stolbov and S.A. Ivanov) .

Type deposition — The holotype is deposited in the collection of the Senckenberg Institution , Görlitz, Germany ; two paratypes are deposited in the collection of the Tyumen State University Museum of Zoology , Tyumen, Russia .

Etymology — The specific name archicostulata refers to the costulae and transcostula, which form the arch-like structure on the prodorsum.

Remarks — Lanceoppia ( Bicristoppia) archicostulata n. sp. is morphologically most similar to L. ( Bicristoppia) bicristata (Hammer, 1962(b)) from Argentina in having costulae, long notogastral setae and lanceolate bothridial setae. However, the new species differs from the latter by the well-developed transcostula ( vs. transcostula absent), the presence of a median indentation on the rostrum ( vs. rostrum rounded) and by setae la and lm being the longest on the notogaster ( vs. dorsal notogastral setae similar in length).