Cunaxa sergeyenkoi, Kalúz & Ermilov, 2022

Kalúz, Stanislav & Ermilov, Sergey G., 2022, Two new species of Cunaxa (Acari: Prostigmata: Cunaxidae) from Vietnam, Zootaxa 5087 (4), pp. 541-557 : 548-553

Cunaxa sergeyenkoi sp. n.

( Figs 5–8 )

Diagnosis (female). Hysterodorsal setae smooth, hysterosomal median plate present. Palpal femur with a short and straight telofemoral apophysis, and with palpal tibiotarsal setae of different lengths. Venter with 4 pairs of sts between coxae IV and genital region; Basifemoral setal formula I–IV: 4-4-2-1.

Description (holotype, female). Idiosoma. Body length 310, width 205, 1 specimen measured.

Dorsum ( Fig. 5 ): Propodosoma with triangular shield with smooth central part and finely punctate margins, bearing a pair of anterior (at) and posterior (pt) setose trichobothria and also two pairs of tactile setae (lps,mps). Anterior trichobothrium 186 and posterior trichobothrium 236 long, distance between bases of at–at and pt–pt 25 and 109, respectively. Propodosomal shield connected with large smooth hysterosomal shield. Six pairs of tactile dorsal setae present on hysterosoma; c 2, c 1 –h 1, of which c 1 –e 1 situated on hysterosomal shield and f 1 –h 1 on soft cuticle. Length of setae c 1 46, c 2 20, d 1 22, e 1 20, f 1 39 and h 1 37. Distance between bases of setae c 1 –c 1 70, about two times length of c 1; d 1 –d 1 60 about three times length of d 1; e 1 –e 1 50 about two and half times longer e 1; f 1 –f 1 21, half times length of f 1; h 1 –h 1 18, half times than length of h 1, cupule im present.

Venter ( Fig. 6 ). Coxal plates weakly sclerotized, coxae I–II and III–IV contiguous and finely striate. Setal formula of coxae I–IV: 3-1-3-2 sts. Venter of hysterosoma ( Fig. 6 ) with two pairs of simple centro–medial setae 18 long between coxae II and III on longitudinally striated integument, and with 3 pairs of hysterogastral setae each 22 long on transversally striated integument arranged anteriorly to genital plates. A pair of genital plates (each 47 long and 23 wide) with four pairs of simple setae on weakly sclerotized genital plates, setae nearly equal in length: g 1 16; g 2 17; g 3 17; g 4 17 (from anterior to posterior, respectively) and a pair of adjacent ps 1 21 (20–21), ps 2 not visible. This arrangement of genital setae is unusual, we examined only one specimen of this species and we have not the opportunity to study and compare any possible variability in the positions of genital setae.

Gnathosoma ( Fig7A–C ). Five–segmented palp 178 long with palpal tibiotarsus very lightly apically curved. Palp ( Fig. 7A ) with gently sparcely punctate surface. Palpal chaetotaxy as follows: trochanter—without setae, basifemur (length/width) 39/25—1 dorso–medial simple seta 9 long; inner surface of telofemur 33/23 with 1 latero–medial apophysis 12/3, dorso–distal seta 11 long; inner ventral surface of genu 39/16 with 1 latero–distal spine–like seta 15/3, dorsally with 1 medio–distal spine–like seta 15 long; tibiotarsus 60/8 inner surface with 1 simple proximal seta 25 and medially with 1 stout spine–like seta 19/4; outer surface with 1 dorso–medial simple seta 8; medio–lateral simple seta 17, dorso–distal solenidion 6 and terminating with small short claw.

Chelicera ( Fig. 7C ). Slender, 119/17, cheliceral segment I as well as the proximal part of segment II with fine punctation, with distal seta 9 long.

Subcapitulum ( Fig. 7B ). Subrectangular, basal part 70/67, distally cone–shaped 68/34 with two pairs of short adoral setae and four pairs of hypognathal setae (hg). Setae hg 4 32 long, about two times longer than hg 2 16, two times longer than hg 1 14 and about two times longer than hg 3 22. Coxal region of subcapitulum finely punctate, base of subcapitulum with subcuticular reticulate pattern.

Legs ( Fig. 8 ). All legs smooth, legs I–III shorter than leg IV. Chaetotaxy I–IV (excluding coxae) as follows: trochanters 1-1-1-1 sts; basifemora 4-4-2-1 sts; telofemora 4-4-4-4 sts; genu I—3 asl, 4 sts; genu II—2 asl, 4 sts; genu III—1 asl, 4 sts; genu IV—5 sts; tibia I—2 asl, 4 sts; tibia II—1 bsl, 5 sts; tibia III—1 bsl, 5 sts; tibia IV, 1 smooth T, 4 sts; tarsus I—4 asl, famulus, 11 sts, 1 dtsl, pretarsus with 1 dorsal and 1 ventral sts on each lobe; tarsus II—4asl, 1 dtsl, 10 sts, pretarsus with 1 dorsal and 1 ventral sts on each lobe; tarsus III—1 dtsl, 11 sts, pretarsus with 1 dorsal and 1 ventral sts on each lobe; tarsus IV—1 dtsl, 7 sts, pretarsus with 1 dorsal and 1 ventral sts on each lobe. Length/width of leg segments I – IV (coxa and trochanter not measured): basifemur 65/27; telofemur 25/27; genu 28/20; tibia 32/17; tarsus 115/16.

Male and developmental stages: Unknown.

Material examined. Holotype: Vietnam, Dong Nai Province, Dong Nai Biosphere Reserve , 11°23’ N, 107°22’ E, forest plantations (mainly of Dipterocarpaceae ), soil and litter (sifter), 02 December 2013, coll, A.E. Anichkin and S.G. Ermilov – 1 female.

Type deposition. Holotype — SNMB.

Etymology. The new species is named in honour of Dr. Alexey L. Sergeyenko ( Ukraine) for his valuable contribution to the taxonomy of Cunaxidae .

Remarks. Female of Cunaxa sergeyenkoi sp. n. differs from two most close species, Cunaxa bochkovi Khaustov & Kuznetsov, 1998 and from C. womersleyi Baker & Hoffmann, 1948 , by chetotaxy of basifemora I–IV: 4-4-2-1 sts. In C. bochkovi and C. womersleyi , basifemoral chaetotaxie I–IV are 3-3-3-1 sts and 4-4-3-1 sts, respectively.

Figures

FIGURE5. Cunaxa sergeyenkoi sp. n., dorsal view of female idiosoma.

FIGURE6. Cunaxa sergeyenkoi sp. n., ventral view of female idiosoma.

FIGURE7. Cunaxa sergeyenkoi sp. n., gnathosoma of female. A—palp, dorsal view, B—subcapitulum, ventral view, C— chelicera, dorsal view.

FIGURE8. Cunaxa sergeyenkoi sp. n., legs I–IV of female (left side, dorsal view).