Setogalumna luzonica, Ermilov, Sergey G. & Corpuz-Raros, Leonila, 2015

Ermilov, Sergey G. & Corpuz-Raros, Leonila, 2015, New species of oribatid mites with auriculate pteromorphs (Acari, Oribatida, Galumnidae) from the Philippines, Zootaxa 3905 (4), pp. 511-528 : 522-527

Description of Setogalumna luzonica sp. n.

( Figs 19–27 )

Diagnosis. Body size: 813–1045× 697–830. Rostral, lamellar and interlamellar setae developed, thin, smooth. Bothridial setae with lanceolate head. Lamellar and sublamellar lines divergent in distal part. Anterior notogastral margin not developed. Notogastral and anogenital setae of medium size. Four pairs of porose areas: Aa elongate oval, oriented transversely. Median pore absent. Adanal lyrifissures inverse apoanal. Postanal porose area elongate trapezoid to triangular with rounded corners.

Description. Measurements. Large species. Body length: 1029 (holotype: male), 813–1045 (five paratypes: two females, three males); notogaster width: 813 (holotype), 697–830 (five paratypes).

Integument ( Figs 19 , 20 , 26 ). Body color brown. Body surface smooth, but epimeral region except central part with longitudinal stria (often visible only in dissected specimens under high magnification, ×1000). Genital plates with one to two longitudinal stria in medial parts and numerous weakly visible stria in lateral parts. Whole body covered by dense cerotegumental microgranules (diameter less than 1).

Prodorsum ( Figs 19 , 21 , 23–25 ). Rostrum rounded. Rostral (69–82) and lamellar (41–57) setae simple, thin, smooth. Interlamellar setae (90–108) setiform, with attenuate tip, smooth. Bothridial setae (118–131) with long stalk and short, sparsely barbed, lanceolate head. Exobothridial setae and their alveoli absent. Porose areas Ad elongate oval, transversely oriented (36–41 × 8–12). Sublamellar lines distinct, curving backwards; lamellar lines almost straight, parallel to sublamellar lines in basal part and divergent in distal part.

Notogaster ( Figs 19 , 21, 22 , 27 ). Anterior notogastral margin not developed. Dorsophragmata short, weakly longitudinally elongated. Ten pairs of notogastral setae of medium size (45–57). Four pairs of porose areas with distinct borders: Aa elongate oval, oriented transversely (61–90 × 12–20); A1 rounded (diameter 24–28), A2 (24–36 × 16–20) and A3 (36–41 × 16–24) oval. Setae la inserted posteriorly to Aa. Lyrifissures im located anteriorly to A1. Opisthonotal gland openings located antero-laterally to A2. Median pore absent.

Gnathosoma . Morphology of subcapitulum, palps and chelicerae generally typical for Galumnidae (for example, Engelbrecht 1969, 1972; Ermilov & Anichkin 2010; Ermilov et al. 2011). Subcapitulum longer than wide (180–184 × 151–164). Subcapitular setae simple, slightly barbed: a (41–49) longer and thicker than m (32) and h (20–28); m usually thinnest. Two pairs of adoral setae (24) setiform, barbed. Palps (151–155) with setation 0–2–1–3–9(+ω). Solenidion straight, thickened, blunt-ended, attached to eupathidium. Chelicerae (225–229) with two setiform, barbed setae; cha (65–69) longer than chb (41–45). Trägårdh’s organ distinct, tapered.

Epimeral and lateral podosomal regions ( Fig. 20 ). Apodemes (1, 2, sejugal, 3) well visible. Four pairs of epimeral setae (1b, 3b, 4a, 4b) present; all similar in length (28–32), thin, smooth. Pedotecta II rectangular, rounded anteriorly in ventral view. Discidia triangular. Circumpedal carinae directed laterally to the insertions of 4a.

Anogenital region ( Figs 20 , 22 ). Six pairs of genital setae (g 1– g 6, 28–32), one pair of aggenital (28–32), two pairs of anal (28–36) and three pairs of adanal (28–36) setae thin, smooth. Anterior edge of genital plates with two setae. One specimen has three pairs of aggenital setae. Adanal lyrifissures located inverse apoanal. Adanal setae ad 3 inserted laterally to iad. Postanal porose area elongate trapezoid to triangular with rounded corners (57–61 × 36–41).

Legs. Morphology of leg segments, setae and solenidia generally typical for Galumnidae (for example, Engelbrecht 1969, 1972; Ermilov & Anichkin 2010; Ermilov et al. 2011). Formulae of leg setation and solenidia: I (1–4–3–4–20) [1–2–2], II (1–4–3–4–15) [1–1–2], III (1–2–1–3–15) [1–1–0], IV (1–2–2–3–12) [0–1–0]; homologies of setae and solenidia indicated in Table 1 .

Material examined. Holotype (male) and five paratypes (two females, three males): Philippines, Luzon Island, Mount Makiling, Makiling Botanic Gardens, Los Baños, Laguna, in litter from plantation of narra ( Pterocarpus indicus ), 8.VI.1975, collected by J.M. Sotto & R.C. Garcia.

Type deposition. The holotype is deposited in the collection of the Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russia; three paratypes are deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia, two paratypes are deposited in the Museum of Natural History, University of the Philippines Los Baños, College, Laguna, Philippines.

Etymology. The specific name “ luzonica ” refers to island origin, Luzon.

Remarks. In presence the lamellar and interlamellar setae, Setogalumna luzonica sp. nov. is similar to S. excellens P. Balogh, 1985 from Australia. However, it clearly differs from the latter by its larger body size (813–1045× 697–830 versus 543–578 × 361–381 in S. excellens ), lanceolate bothridial setae (versus clavate in S. excellens ), absence of anterior notogastral margin (versus present in S. excellens ), elongate, transversely oriented notogastral porose areas Aa (versus oval, longitudinally oriented in S. excellens ) and lamellar and sublamellar lines divergent in distal part (versus parallel in S. excellens ).

Figures

FIGURE 19. Setogalumna luzonica sp. nov., adult: dorsal view. Scale bar 400 Μm.

FIGURE 20. Setogalumna luzonica sp. nov., adult: ventral view. Scale bar 400 Μm.

FIGURES 21 – 22. Setogalumna luzonica sp. nov., adult: 21 — dorso-lateral view of prodorsum and anterior part of notogaster, pteromorph; 22 — posterior view. Scale bar 200 Μm.

FIGURES 23 – 27. Setogalumna luzonica sp. nov., adult, brightfield micrographs: 23 — rostral seta; 24 — lamellar and sublamellar lines and lamellar seta; 25 — medio-distal part of bothridial seta; 26 — microgranules on posterior part of notogaster; 27 — seta c on pteromorph. Scale bars 20 Μm (23 – 26), 50 Μm (27).