Onchodellus kosensis, Özbek, 2023

Özbek, Hasan Hüseyin, 2023, The genus Onchodellus Berlese in Türkiye (Mesostigmata: Pachylaelapidae), with a new record and three new species, Zootaxa 5263 (2), pp. 285-296 : 291-292

Onchodellus kosensis sp. nov.

( Figures 7–8 , 12, 15, 19 , 29 , 40, 44 )

Diagnosis: Length of idiosoma less than 600; two pairs of postero-lateral teat-like gland pores present, gdZ 1 in anti-axial position to line Z1–Z2; J4 and J5 of variable length, J5 very short (10–14), ratio of J4 / J5 3–3.50, anterior tips of peritremes extending over dorsal side of shield; soft integument of idiosoma with 13 pairs of setae; specific ornamentation on surface of ventral shields.

Material examined: Holotype, female, Gümüşhane, Köse Town; Köse Mountains , 40° 16′ N, 39° 37′ E, alt. 1767 m, 10 May 2012, litter, and moss under Pinus sp . Paratypes: six females, same data as holotype ; one female, Köse Mountains , 40° 16′ N, 39° 38′ E, alt. 1794 m, 26 October 2007, litter and soil under Salix sp .; one female, Tokat, between of Reşadiye and Niksar Towns, 40° 26′ N, 37° 03′ E, alt. 598 m, 27 April 2008, litter of walnut; Köse Mountains , 40° 17′ N, 39° 35′ E, alt. 1790 m, 31 May 2008, litter of Pinus sp. and Quercus sp .; three females, Köse Mountains , 40° 17′ N, 39° 28′ E, alt. 1789 m, 31 May 2008, litter under Pinus sp .; one female, Tokat, Reşadiye Town, Zinav Lake , 40° 26′ N, 37° 14′ E, alt. 883 m, 14 April 2012, in moss ; one female, Reşadiye Town , 40° 25′ N, 37° 13′ E, alt. 573 m, 14 April 2012, in moss; a female, Gümüşhane, 40° 15′ N, 38° 57′ E, alt. 1573 m, 23 April 2012, litter under Quercus sp. ; a female, Gümüşhane, 40° 15′ N, 38° 57′ E, alt. 1570 m, 23 April 2012, in dung ; one female, Köse Mountains , 40° 16′ N, 39° 37′ E, alt. 1867 m, 01 May 2012, in moss ; one female, Köse Mountains , 40° 16′ N, 39° 37′ E, alt. 1767 m, 10 May 2012, in moss ; two females, Köse Mountains , 40° 18′ N, 39° 38′ E, alt. 1880 m, 19 May 2012, litter under Pinus sp .; three females, Köse Mountains , 40° 16′ N, 39° 37′ E, alt. 1767 m, 19 May 2012, litter near stream ; one female, 40° 18′ N, 39° 39′ E, alt. 1835 m, 13 June 2012, litter of Berberis sp.

Dorsum ( Figure 7 ). Dorsal shield 470–550 long, 308–350 wide at widest point, length/width 1.45–1.57, oval, surface reticulate, with 30 pairs of smooth and pointed setae and two pairs of postero-lateral teat-like gland pores gdZ1 and gdS4, well separated; gland pores gdZ 1 in antiaxial position to line Z1–Z2. Dorsal setae j1 20–25, z1 8–10, J1 44–50, J2 45–48, J4 40–42, J5 very short (10–14), rate of J4 / J5 3–3.50, other dorsal setae 40–60 long.

Venter ( Figure 8 ). Sternal shield 166–185 long, 90–95 wide at the level of coxae II, its surface decorated with reticulate pattern, with four pairs of pointed setae and three pairs of pores; st1 (about 60) distinctly longer than other sternal setae. Genitiventral shield 175–185 long, 178–196 wide, slightly wider than long, length/width 0.96–0.99 ornamented with polygonal pattern, with two pairs of setae ( Fig. 40 ). Anal shield 65–77 long, 94–101 wide, length/ width 0.65–0.77, triangular, decorated with reticulate lines. One pair of bar-shaped metapodal shields present. Lateral and opisthogastric soft integument with 13 pairs of setae (six pairs marginal and seven pairs opisthogastric). Anterior tips of peritremes extend to dorsal side of idiosoma, between setae z1 and z2.

Spermathecal apparatus. Sperm access system associated with coxae III, tubes long, apical section widened, conical shaped ( Fig. 15 ).

Gnathosoma . Hypostome with seta h3 longest, h2 and palp coxal seta pc shortest and subequal in length; corniculi horn-like and lanceolate, deutosternal groove with six rows of denticles. Epistome with straight denticulate lateral margins and central projection with strong apical denticle ( Fig. 12 ), its surface decorated as in Fig. 44 . Chelicera well developed with strong subdistal teeth; movable digit about 82 long, with a large subdistal tooth, a small subdistal tooth, and unidentate terminal hook; fixed digit about 67 long (to dorsal seta), with a minute pilus dentilis ( Fig. 29 ). Arthrodial brush short.

Legs. Chaetotaxy normal for the genus ( Mašán, 2007). Tarsus II with a thicker spur-like seta pl1 ( Fig. 19 ).

Etymology. This species is named after Köse Mountains in Gümüşhane Province, Türkiye, where most specimens were collected.

Taxonomic notes. In this study, many females were collected from the study area, but no males, so Onchodellus kosensis sp. nov. was identified and described from females only. Most species in the genus Onchodellus are morphologically very similar, so it is difficult to distinguish them clearly, especially in the absence of males, which have many important diagnostic characters such as spermatodactyls and tarsus II. Nevertheless, O. kosensis can be distinguished from similar species, especially using the classification of Mašán (2007) and the checklist of Mašán & Halliday (2014).

Mašán (2007) presented another species group, namely O. strigifer , whose members share some important features, e.g., two pairs of teat-like gland pores (gdS4, gdZ1), gdZ 1 in antiaxial position to the line Z1–Z2, S-shaped spermatodacyl of males, and length of setae J5 less than 20, so O. kosensis seems to be a member of this group and can be compared with these species placed in the European fauna. This new species differs from O. neglectus Mašán, 2007 , O. slovacus Mašán, 2007 , O. striatifer Mašán, 2007 , and O. strigifer (Berlese, 1892) mainly in having 13 pairs of setae on the soft integument of the idiosoma (14 in O. neglectus , 10 in O. slovacus , 12 in O. striatifer , 11 in O. strigifer ), and differs from O. tegulifer Mašán, 2007 by longer dorsal setae, J4 40–42, J5 10–14 (J4 20–30, J5 7–13 in O. tegulifer ), the shape of the idiosoma, ratio length/width 1.45–1.57 (slightly oval in O. kosensis , broadly oval in O. tegulifer , 1.31–1.41), differences on chelicerae, ornamented surface of anal shield (anal shield without ornamentation in O. tegulifer ), different ornamentation on sternal and genitiventral shields. It could also be comparable with O. bregetovae ( Koroleva, 1977) , described from Kyrgyzstan, but differing from this species by the presence of seven pairs of setae on the ophistogastric region of the ventral side (eight pairs in O. bregetovae ) and by the different ornamentation of the dorsal and ventral shields.

Figures

FIGURES 7–8. Onchodellus kosensis sp. nov., female. 7. Dorsal idiosoma; 8. Ventral idiosoma.

FIGURES 9–23. Onchodellus spp., female. 9–12. Epistome (O. karawaiewi, O. acrophilus, O.circularis, O. kosensis, respectively); 13–15. Spermathecal apparatus (O. acrophilus, O.circularis, O. kosensis, respectively); 16–19. Tarsus II (O. karawaiewi, O. acrophilus, O.circularis, respectively): O. acrophilus, male. 20. Tarsus II; 21. Femur, genu, tibia of Leg II: O.circularis, male. 22. Anterior part of holoventral shield; 23. Tarsus II.

FIGURES 24–29. Onchodellus karawaiewi, 24. Chelicera of female; 25. of male. O. acrophilus, 26. Chelicera of female; 27. Chelicera of male. O.circularis, 28. Chelicera of male. O. kosensis, 29. Chelicera of female.

FIGURES 36–44. Onchodellus karawaiewi, female. 36. Surface of ventral shield: O. acrophilus, female. 37. Surface of ventral shield: O. circularis sp. female. 38. Punctation of dorsal shield; 39. Surface of ventral shield: O. kosensis, female. 40. Surface of ventral shield:Onchodellus spp., female.41-44.Epistome (O.karawaiewi, O. acrophilus, O.circularis, O. kosensis, respectively).