Cosmolaelaps siberiensis Joharchi, 2019

Joharchi, Omid, Tolstikov, Andrei V., Khaustov, Alexander A., Khaustov, Vladimir A. & Sarcheshmeh, Mohammadhassan Abbasi, 2019, Review of some mites (Acari: Laelapidae) associated with ants and bumblebees in Western Siberia, Russia, Zootaxa 4613 (1), pp. 71-92 : 77-81

Cosmolaelaps siberiensis Joharchi sp. nov.

Figures 21–37 .

Type material. Holotype, female, RUSSIA, Tyumen Province, vicinity of Uspenka , 57°04’N, 65°04’E, 21 May 2018, O. Joharchi coll., in the nest of Myrmica rubra (L.) ( Hymenoptera : Formicidae ) . Paratypes: eight females, same data as holotype (deposited in TUMZ).

Description. Female (n= 9 specimens)

Dorsal idiosoma ( Figs 21 , 26, 28 ). Dorsal shield oval shaped, 435–445 long, 280–298 wide, covering most of idiosoma; shield with weak reticulation, more distinct in opisthonotal and lateral regions. Shield with 39 pairs of setae: 22 pairs of podonotal setae on shield, and 17 pairs of opisthonotal setae on shield, including two pairs of Zx setae between J and Z setae and one or two unpaired supernumerary seta Jx; all setae slightly swollen at base ( Fig. 28 ), with pointed tips, and sub-equal in length (29–35) except j1, Z5 (17–19) simple and thickened, z1 (12–14) simple, J5 (22–25) ( Figs 14 , 26 and 28). All setae long enough to reach at most to base of next posterior seta but never past it. Shield with 14 pairs of discernible pore-like structures, eight on podonotum (id1, id2, 1d4, id5, gd1, gd2, gd5, gd6) and six on opisthonotum (idm1–idm4, idS1, idx). Shape, position and relative length and shape of setae shown in Figures 21 , 26, 28 .

Ventral idiosoma ( Figs 22 , 27, 29, 30 ). Tritosternum with paired pilose laciniae (63–68), columnar base 21–28 × 13–16 wide; pre-sternal area with transverse lightly sclerotised lines, fused to sternal shield. Sternal shield (length 93–98) narrowest between coxae II (87–89), widest between coxa II–III (131–133), with slightly concave posterior margin and with a median notch in its anterior margin ( Figs 22 , 27, 30 ). Shield with three pairs of simple and subequal sternal setae, st1 (38–40), st2 (38–40), st3 (37–39) and two pairs of poroids (iv1 and iv2 slit-like, near to setae st1 and between st2 and st3) ( Figs 22 , 27, 30 ); antero-lateral corners resemble a narrow strip extending between coxae I–II, lateral margins alongside coxa II–III fused with endopodal plates, one pair of simple metasternal setae st4 (29–32) and pore-like iv3 inserted on soft cuticle posterior to sternal shield; endopodal plates III/IV elongate, narrow, curved. Genital shield elongate, slightly tapering posteriorly, width (93–99) and length (201–205). Surface with a few irregular diagonal lines and polygonal cells, shield bearing smooth genital setae st 5 (37–39) on the edges, expanded slightly just posterior to genital setae ( Figs 22 , 29, 30 ). Paragenital poroids (iv5) located on soft cuticle lateral to shield behind st 5. Anal shield subtriangular, length 70–74, width 54–57, anterior half with lineate ornamentation and with a pair of lateral pores (gv3); bearing smooth post-anal seta and a pair of smooth para-anal setae, almost equal in length (19–22), cribrum small. Soft opisthogastric cuticle surrounding genital and anal shields with one pair of suboval metapodal plates (22–25 long × 7–9 wide) and 18 pairs (including st4) of moderately thick setae (Jv1–Jv5, Zv1–Zv 5, R1–R4, UR4–UR6); almost all setae uniform in length (32–37), and arising on small sclerotised platelets ( Figs 22 , 27, 29 ). Peritreme long, extending to anterior level of coxa I, peritrematal shield very narrow, free from exopodal shields, each shield bearing three discernible pore-like structures, two lyrifissures ip and a gland pore gp on post-stigmatic section ( Fig. 22 ); anterior part of shield fused with dorsal shield.

Gnathosoma . Epistome almost smooth with a few denticles ( Figs 23 , 31 ). Hypostomal groove with six transverse rows of denticles, each row with about 8–15 small teeth. Hypostome with four pairs of setae, internal posterior hypostomal setae h3 longest (32–35), h1 (23–28), h2 (15–17), palpcoxal pc (23–26) ( Figs 24 , 32 ). Corniculi small and horn-like, reaching beyond palp trochanter. Chaetotaxy of palps: trochanter 2, femur 5, genu 6, tibia 14, tarsus 15, all setae smooth and needle-like and palp tarsal claw two-tined ( Fig. 34 ). Internal malae with two pairs of lobes: inner lobes smooth, pointed; outer lobes, curved, with internal surface and lateral coarsely fimbriate; labrum with pilose surface. Fixed digit of chelicera with three teeth: an offset small tooth and two adjoining small teeth at the level of a short, setiform pilus dentilis and a proximal tooth, dorsal seta short, thick and prostrate, movable digit bidentate, arthrodial membrane with a rounded flap and normal filaments; cheliceral lyrifissures distinct ( Figs 25 , 33 ).

Insemination structures: Not seen, apparently unsclerotised.

Legs ( Figs 35, 36, 37 ). Legs II and III short (277–290, 266–278), I and IV longer (419–430, 353–362) (excluding pre-tarsus). Chaetotaxy normal for free living Laelapidae : Leg I: coxa 0 0/1, 0/1 0, trochanter 1 0/2, 1/1 1, femur 2 2/1, 3/3 2, genu 2 3/2, 3/1 2, tibia 2 3/2, 3/1 2. Leg II ( Fig. 35 ): coxa 0 0/1, 0/1 0, trochanter 1 0/1, 0/2 1, femur 2 3/1, 2/2 1 (ad1 & pd2 slightly thickened), genu 2 3/1, 2/1 2, tibia 2 2/1, 2/1 2. Leg III ( Fig. 36 ): coxa 0 0/1, 0/1 0, trochanter 1 0/2, 0/1 1 (al thickened), femur 1 2/1, 1/0 1 (ad1 thickened), genu 2 2/1, 2/1 1, tibia: 2 1/1, 2/1 1. Leg IV ( Fig. 37 ): coxa 0 0/1, 0/0 0, trochanter 1 0/2, 0/1 1 (al thickened), femur 1 2/1, 1/0 1 (ad1 & ad2 thickened), genu 2 2/1, 3/0 1 (av slightly thickened), tibia 2 1/1, 3/1 2 (av and pv slightly thickened). Tarsi II–IV with 18 setae (3 3/2, 3/2 3 + mv, md). All pre tarsi with well developed paired claws, rounded pulvilli, and a long thin stalk.

Male. Unknown.

Etymology. The specific name is derived from the name of the region (Western Siberia) in which the type locality occurs.

Notes. Cosmolaelaps siberiensis Joharchi sp. nov. is very similar to C. mixta ( Shcherbak, 1971) , C. pumili ( Karg, 1988) , C. lingua ( Karg, 1987) , C. aegyptiacus Nasr & Momen, 2016 , C. sungaris (Ma, 1996) and C. shenyangensis (Bei et al., 2003) in the shape of dorsal setae and the elongated genital shield, described from Ukraine, Saint Lucia, Italy, Egypt and China, respectively. It differs from C. pumili because it has much larger body size (435–445 long, 280–298 wide) but shorter dorsal setae, especially setae Z5, epistome almost smooth with a few denticles, fixed digit of chelicera with three teeth and leg I shorter than length of dorsal shield (versus body size smaller (380 long, 220 wide), dorsal setae long especially in opisthonotal area and reaching well past base of next posterior setae, setae Z5 long, epistome irregularly denticulate, fixed digit of chelicera with five teeth and leg I longer than length of dorsal shield in C. pumili ). Cosmolaelaps siberiensis differs from C. lingua by its thick opisthogastric setae which arising on small sclerotised platelets, two pre-sternal plates conspicuous and sternal shield with a median notch in its anterior margin (versus opisthogastric setae simple, thin and sclerotised platelets absent, pre-sternal plates joint together and sternal shield without any notch in its anterior margin in C. lingua ). It differs from C. aegyptiacus because setae Z5 are smooth and without any barbs, metasternal setae st4 inserted on soft cuticle, metasternal platelets absent, fixed digit of chelicera with three teeth and genital shield longer (201–205) (versus setae Z5 well barbed, metasternal setae st4 inserted on metasternal shields, fixed digit of chelicera with five teeth in C. aegyptiacus and length of genital shield 173 – 195 in C. aegyptiacus ). It differs from C. sungaris and C. shenyangensis by its lanceolate dorsal shield setae (slightly swollen at base and pointed tip), thick opisthogastric setae which arise on small sclerotised platelets, fixed digit of chelicera with three teeth, posterior part of shield slightly tapering and well pass from Jv1 and size of anal shield (70–74, width 54–57) smaller than both species (versus dorsal shield setae bristle and scimitar like in C. sungaris and C. shenyangensis , respectively, opisthogastric setae simple, thin, sclerotised platelets absent, fixed digit fixed digit of chelicera with five teeth in both species including two larger and three small teeth, posterior part of genital shield well rounded and never pass Jv 1 in both C. sungaris and C. shenyangensis and anal shield larger [94 × 82 and 86 × 76 in C. sungaris and C. shenyangensis , respectively]). Cosmolaelaps siberiensis is similar to C. mixta ( Shcherbak, 1971) , but can be readily distinguished from this species by following characters: dorsal shield covering whole of idiosoma and setae are mostly longer than in C. mixta and dorsal shield not covering whole of idiosoma in C. mixta , genital shield much larger (201–205 length × 93–99 width) than in C. mixta (94 × 77), almost all opisthogastric setae arising on small sclerotised platelets and moderately thick, versus opisthogastric setae thin and without any such small sclerotised platelets in C. mixta , sternal shield with a median notch in its anterior margin but a median notch absent on anterior margin of sternal shield in C. mixta , the anal shield in Cosmolaelaps siberiensis is longer than wide, but in C. mixta is wider than long, peritreme extending to anterior level of coxa I but longer in C. mixta and extending to mid-level of coxa I.

In the classification of Karg (1981), C. siberiensis falls into the nasoseta species group of Hypoaspis (Cosmolaelaps) , because almost all dorsal shield setae are slightly swollen at the base and pointed at the tip (lanceolate), all dorsal setae are the same shape and sub-equal in length except setae j1 and Z5 simple and short, distance between genital and anal shield is shorter than length of anal shield and leg I shorter than length of idiosoma.

These character states are shared with C. mediocuspis ( Karg, 1981) ; C. transvaalensis Ryke, 1963 and C. vacua , but C. siberiensis can be easily distinguished from all those species by its genital shield much longer and wider (posterior part of shield slightly tapering and well pass from Jv1), almost all opisthogastric setae arising on small sclerotised platelets and moderately thick, while neither of these character states is seen in the above species.

Figures

FIGURES 21–25. Cosmolaelaps siberiensis Joharchi sp. nov., female. 21, dorsal idiosoma; 22, ventral idiosoma; 23, epistome; 24, subcapitulum; 25, chelicera.

FIGURES 26–34. DIC micrographs of Cosmolaelaps siberiensis sp. nov., female. 26, idiosoma in dorsal view; 27, idiosoma in ventral view; 28, general view of some dorsal setae, 29, genital and anal shields, general view of some opisthogastric setae; 30, genital and sternal shields; 31, epistome; 32, subcapitulum; 33, chelicera, fixed digit; 34, palp and apotel.

FIGURE 35–37. Cosmolaelaps siberiensis sp. nov., female. 35, leg II; 36, leg III; 37, leg IV.

FIGURES 14–20. DIC micrographs of Cosmolaelaps neocuneifer, female. 14, idiosoma in dorsal view; 15, idiosoma in ventral view; 16, general view of some dorsal setae; 17, general view of some opisthogastric setae, and post-anal seta; 18, epistome; 19, subcapitulum; 20, chelicera, fixed digit.