Macrocheles niksarensis, Özbek, 2017

Özbek, Hasan Hüseyin, 2017, A review of the macrochelid mites of Turkey (Acari: Macrochelidae), with new records and descriptions of three new species, Zootaxa 4317 (3), pp. 559-572 : 563-564

Macrocheles niksarensis sp. nov.

( Figures 9‒15 ; 29‒31)

Diagnosis. DOrsal shield with 29 pairs Of setae, all pilOse in distal 2/3; setae z1 shOrt, nOt reaching base Of j2; setae J3 lOnger than J2; all sternal setae smOOth and needle-like, except pilOse pOst-anal seta; dOrsal cheliceral seta machete-like, and lateral prOcesses Of epistOme fused basally tO the stem Of the median prOcess.

Specimens examined. HOlOtype, female, Turkey, TOkat PrOvince, Niksar TOwn, Eryaba Village , 40° 33' N, 36° 47' E, alt. 688 m, 30 September 2008, litter and decaying wOOd frOm Quercus sp . Paratypes, 10 females, same data as hOlOtype .

Description. Female

Dorsum ( Fig. 9 ). DOrsal shield OblOng, 865‒935 lOng, 520‒585 wide at the widest pOint (n=16), reticulated with pOlygOnal pattern and cOvered with fine punctatiOn, with 29 pairs Of setae, all pilOse in distal 2/3 (J3 present); mOst dOrsal setae 50‒70, setae z1 shOrt, 18‒22, nOt reaching bases Of seta j2, s5 distinctly lOnger than Other setae 65‒70 lOng, J2 40‒50 lOng and shOrter than J3, setae J 5 30‒35, Z5 35‒40; S5 40‒50. AnteriOr tips Of peritremes reaching beyOnd bases Of setae z1.

Venter ( Fig. 10 ). Sternal shield 185‒201 lOng, 170‒181 wide at the mid-level Of cOxae II, similar in length; surface Ornamented with pOlygOnal pattern and punctatiOn, bearing three pairs Of smOOth and pOinted setae, their length 50‒60 ( Fig. 29 ). Metasternal shields free, elliptical, each bearing a pOre and a smOOth seta, st4. Epigynal shield 190‒203 lOng, 200‒222 wide, helmet-like, Ornamented with netwOrk Of fine punctatiOn, with a pair Of smOOth setae st5, and lateral sclerites. Ventri-anal shield 270‒330 lOng, 270‒310 wide (L/W =0.97‒1.01), Ornamented with pOlygOnal pattern, cOvered with fine punctatiOn, bearing three pairs Of smOOth pre-anal setae, setae Jv1 lOngest (47‒54), Jv2 46‒52, Jv3 40‒44, a pair Of distinctly lOnger para-anal setae (36‒40) and a pilOse pOst-anal seta. AnterOlateral extensiOns Of cribrum weakly visible and reaching bases Of para-anal setae ( Fig. 30 ).

Spermathecal structure. As in Fig. 11 .

Gnathosoma . Setae h3 lOngest, h2 almOst subequal in length tO pc, h1 lOnger than h2. COrniculi hOrn-like. DeutOsternal grOOve with six rOws Of denticles, rOw between setae h1 separated intO twO parts ( Fig. 12 ). EpistOme with a pair Of lateral prOcesses bifurcated distally, a median prOcess deeply bifurcated distally, with lOng spines On its stem ( Fig. 13 ). Chelicerae well develOped, mOvable digit abOut 96 lOng, with twO median teeth and unidentate terminal hOOk, fixed digit abOut 86 lOng tO level Of base Of dOrsal seta, with One distinct median tOOth and a unidentate terminal hOOk, distinct pilus dentilis and a machete-like dOrsal seta. ArthrOdial brush lOng, half as lOng as mOvable digit ( Figs 14 and 31 ).

Legs: ChaetOtaxy typical fOr the genus and family (Evans, 1963). All cOxae with smOOth and pOinted setae. Tarsus II as in Fig. 15 .

Etymology. This species is named after Niksar TOwn (TOkat PrOvince) where it was cOllected.

Notes. Macrocheles niksarensis is a very characteristic EurOpean species in the genus. It is distinguishable frOm Other species in the genus by mOre than 28 pairs Of setae (29 pairs Of setae present), all Of them pilOse and brush-like, J3 present, the shape Of the epistOme (lateral prOcesses fused basally and the median prOcess deeply bifurcated distally), a machete-like dOrsal seta and the fOrm Of the sperm inductiOn system.

Mašán (2003) presented a key fOr the genus Macrocheles and separated the EurOpean species intO twO grOups. Species in the first grOup have all dOrsal shield setae smOOth and pOinted, while species in the secOnd grOup have vertical setae j1 always pilOse Or plumOse, and mOst species Of the secOnd grOup have 28 pairs Of setae, except fOr M. punctatissimus Berlese, 1918 and M. ivanovi BregetOva & KOrOleva, 1960 . These twO species have a dOrsal shield with 1–4 unpaired median setae. Macrocheles niksarensis is similar tO them, but it clearly differs frOm them by many characters presented in the descriptiOn and diagnOsis.

Figures

FIGURES 9 ‒ 10. Macrocheles niksarensis, female. 9. Dorsal shield; 10. Ventral shields.

FIGURES 11 ‒ 15. Macrocheles niksarensis, female. 11. Spermathecal structures; 12. Hypostome; 13. Epistome; 14. Chelicera; 15. Tarsus II.

FIGURES 25 – 34. 25. Nothrholaspis scutivagus, female, ornamentation of sternal shield; 26. Nothrholaspis scutivagus, female, free platelets in soft integument; 27. Nothrholaspis scutivagus, female, platelets fused with ventri-anal shield; 28. Nothrholaspis scutivagus, female, chelicera. 29. Macrocheles niksarensis, female, ornamentation of sternal shield; 30. Macrocheles niksarensis, female, ventri-anal shield; 31. Macrocheles niksarensis, female, chelicera. 32. Holostaspella bidentata, female, ornamentation of sternal shield; 33. Holostaspella bidentate, female, ventri-anal shield; 34. Holostaspella bidentata, female, chelicerae.