Monoschelobates hemileiformis, Ermilov & Sandmann & Marian & Maraun, 2013

Ermilov, S. G., Sandmann, D., Marian, F. & Maraun, M., 2013, THREE NEW SPECIES OF ORIBATID MITES (ACARI, ORIBATIDA) FROM ECUADOR Sergey G. E, Dorothee S, Franca M and Mark M, Acarologia 53 (1), pp. 111-123 : 119-122

Monoschelobates hemileiformis n. sp.

( Figures 5-6 )

Diagnosis — Body size 448 – 498 x 265 – 282. Sensilli clavate. Interlamellar setae longer than all prodorsal setae. Notogaster with 10 pairs of thin, smooth notogastral setae. Aggenital setae present.

Measurements — Body length 498 (holotype), 448 – 498 (mean 471; five paratypes); notogaster width 282 (holotype), 265 – 282 (mean 272; five paratypes).

Integument — ( Figures 5 A-C). Body color brown. Body surface smooth. Posterior part of notogaster and epimeral region with irregular muscle sigilla.

Prodorsum — ( Figures 5A, C, D ). Rostrum rounded in dorsal view. Lamellae located dorsolaterally, little longer than half of prodorsum (see in lateral view), without cusps. Translamella absent, but rudimentary parts present nearly to lamellae. Prolamellar and sublamellar lines present. Sublamellar porose areas (Al) round, small (6 – 8). Rostral (53 – 65), lamellar (90 – 102) and interlamellar (164 – 172) setae setiform, barbed. Lamellar setae inserted on the distal part of lamellae. Sensilli (77 – 82) clavate, its head slightly barbed. Exobothridial setae (2 – 4) minute, thin, smooth. Pedotecta I and II typical for genus.

Notogaster — ( Figures 5A, C ). Anterio-medial part straight or weakly convex. Ten pairs of short (24 – 36), smooth notogastral setae present. Four pairs of sacculi (Sa, S1, S2, S3) small. Lyrifissures and opisthonotal gland openings in typical arrangement of the family.

Gnathosoma — ( Figures 6 A-C). Typical for Scheloribatidae ( Ermilov et al. 2011; Ermilov and Kaloez 2012e). Subcapitulum longer than wide: 94 – 102 x 65 – 69. Subcapitular setae setiform; h (24 – 28) and a (16 – 20) slightly barbed, thicker than m (16 – 20). Two pairs of adoral setae (10 – 12) setiform, barbed. Palps (length 61) with setation 0-2- 1-3-9(+1ω). Solenidion attached with eupathidium. Chelicerae (length 102) with two setiform, barbed setae; cha (49) longer than chb (20). Trägårdh’s organ distinct.

Epimeral region — ( Figures 5B ; 6D ). Epimeral setal formula: 3-1-3-3. Setae setiform, smooth. Lengths of setae: 1a, 2a, 3a 8 – 10; others 16 – 20. Discidia triangular, blunt-ended.

Anogenital region — ( Figures 5B ; 6E, F ). Four pairs of genital (g 1, 20 – 24; g 2 - g 4 14 – 16), one pair of aggenital (12), two pairs of anal (12 – 16) and three pairs of adanal (20) setae setiform, smooth. Lyrifissures iad located in paranal position.

Legs — ( Figure 6G ). Typical for Scheloribatidae ( Ermilov et al. 2011; Ermilov and Kaloez 2012e). Claw of each tarsus smooth. Homology of setae and solenidia indicated in Table 3. Famulus short, with small swelling distally. Solenidia simple.

Material examined — Holotype (male) and five paratypes (three males, two females): Southern Ecuador, 4°60’ S, 78°58’ – 79°10’ W, Cajanuma, Podocarpus National Park, 3000 m. a.s.l., upper organic soil layer in mostly undisturbed rain forest, 01.04.2008, collected by D. Sandmann.

Type deposition — The holotype is deposited in the collection of the Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russia ; two paratypes are deposited in the collection of the Siberian Zoological Museum , Novosibirsk, Russia ; three paratypes are in the personal collection of the first author.

Etymology — The specific name " hemileiformis " refers to the similarity of the new species to representatives of the subgenus Scheloribates (Hemileius) Berlese, 1916 .

Remarks — Monoschelobates hemileiformis n. sp. can be distinguished from the type species, M. parvus Balogh and Mahunka, 1969 (see Balogh and Mahunka 1969) known from Brazil by the larger body size (448 – 498 x 265 – 282 versus 254 – 279 x 147 – 162 in M. parvus ), long interlamellar setae, which are considerably longer than lamellar setae (interlamellar and lamellar setae similar in length in M. parvus ), well developed notogastral and anogenital setae (minute in M. parvus ), and presence of aggenital setae (absent in M. parvus ).

PØrez-˝ñigo and Baggio (1991) described the second species of the genus Monoschelobates , M. translamellatus PØrez-˝ñigo and Baggio, 1991 from Brazil. However, this species clearly differs from the type and the present new species by the presence of well-developed pteromorphs (absent or very small – generic character in Monoschelobates ). Hence, in our opinion, Monoschelobates translamellatus should be included in the genus Perscheloribates Hammer, 1973 .

Due to the combination of generic characters (in particular, rudimentary pteromorphs, four pairs of sacculi, ten pairs of short notogastral setae, four pairs of genital setae), the species of the genus Monoschelobates are similar to species of the subgenus Scheloribates (Hemileius) . Only a single main difference is monodactylous leg tarsi in Monoschelobates versus tridactylous in Scheloribates (Hemileius) . Also, the type species of Monoschelobates , M. parvus , is without aggenital setae. Presence or absence of aggenital setae, and variation in numbers of leg claws are not apomorphic characters, therefore it can be used as subgeneric characters. Hence, possibly, Monoschelobates parvus and M. hemileiformis n. sp. should be included in the subgenus Scheloribates (Hemileius) . However, the classification of genera in the family Scheloribatidae is difficult, and the further research on the taxonomic status of Monoschelobates is needed.

Figures

FIGURE 5: Monoschelobates hemileiformis n. sp.: A – dorsal view; B – ventral view, legs, subcapitular setae and palps not shown; C – lateral view of prodorsum, legs and gnathosoma not shown; D – sensillus. Scale bar (A+C) 100 µm, scale bar (D) 20 µm.

FIGURE 6: Monoschelobates hemileiformis n. sp.: A – subcapitulum, left half; B – palptarsus; C – anterior part of chelicera; D – tutorium and epimeral seta 4c; E – genital plate, right; F – anal plate, right; G – leg tarsus I, right, paraxial view. Scale bars (A, C, F, G) 20 µm, scale bar (B, D, E) 10 µm.