Mucroseius insolitus Khaustov & Lindquist 2019, sp. nov

Mucroseius insolitus sp. nov. (Figures 1 ��� 5) Type material Holotype female (slide No 24 ��� 07 ��� 2017 /1)ı Russiaı Altai Republicı Mayminsky Districtı vicinity of Manzherokı 51��49 �� Nı 85��48 �� Eı from the metathoracic spiracular atria of the Black pine sawyer beetleı Monochamus galloprovincialis (Olivierı 1795) ı collected from the surface of felled Scots pine (Pinus sylvestris)ı 24 July 2017ı V. A. Trach coll. Paratypes: three femalesı with same date as holotype; two femalesı Russiaı Tyumen Provinceı Nizhnetavdinsky Regionı vicinity of lake Kuchakı 57��21 �� Nı 66��03 �� Eı from the metathoracic spiracular atria of the Black pine sawyer beetle collected from trunk of living of Scots pineı 31 July 2018ı V. A. Khaustov coll.; one femaleı Austriaı Tirolı under elytra of the Small white-marmorated longhorned beetleı Monochamus sutor (Linnaeusı 1758) ı Kraatz coll. Type deposition Holotype at ZMUO; paratypes at ONUDZı TUMZı and CNCI. Diagnosis Dorsal shield smooth over most of surface but lightly reticulated along margins; with 39 ��� 41 pairs of setae (j1���j6, z1���z6, s1���s6, r2���r6, J1���J5, Z1���Z5, S1���S5, R1���R3) (setae r5, r6, R2, R3 sometimes asymmetrically off shield on one side); length of dorsal shield setae 35 ��� 50 mostly. Sternal shield with posterior margin weakly concaveı arched to level of bases of setae st3. Epigynal shield reticula outline about 10 elongate cells between bases of setae st5. Epistome clearly triramous. Distal flangelike process (mucro) of the fixed chela absent. Tarsus IV with two erect macrosetaeı ad2 and pd2; tibia III with eight setae (seta pl2 absent). Description Female (n = 4) Idiosomal dorsum (Figures 1 and 5 (a)). Dorsal shield oval; 444 (456 ��� 502) long and 248 (251 ��� 260) maximum width at r4 level; smooth over most of surface but lightly reticulated along marginsı midlateral incisions on lateral margins absent; with 39 ��� 41 pairs of setae (usually j1���j6, z1���z6, s1���s6, r2���r6, J1���J5, Z1���Z5, S1���S5, R 1��� R 3 ı but any of j2, z1, z2, s2, J5 sometimes asymmetrically lacking on one sideı or any of r5, r6, R 2, R 3 sometimes asymmetrically off shield on one side) and 23 pairs of distinguishable pore-like structures (seven gland pores and 16 poroids). Soft cuticle with setae R 4��� R 6 (usually visible in ventrolateral regions) and poroids Rp. Setae Z5 sparsely barbedı other dorsal setae simpleı needle-like; measurements of setae: j1 33 ��� 34 (36 ��� 44)ı j2 35 (36 ��� 46)ı j3 40 ��� 41 (42 ��� 46)ı j4 38 ��� 41 (40 ��� 50)ı j5 37 (38 ��� 48)ı j6 40 ��� 42 (42 ��� 55)ı z1 22 (23 ��� 29)ı z2 38 (46 ��� 50)ı z3 42 ��� 46 (48 ��� 55)ı z4 50 (53 ��� 67)ı z5 47 (48 ��� 61)ı z6 38 ��� 44 (44 ��� 55)ı s1 33 (32 ��� 38)ı s2 35 ��� 38 (36 ��� 40)ı s3 44 ��� 51 (46 ��� 63)ı s4 56 ��� 57 (48 ��� 69)ı s5 48 ��� 56 (59 ��� 69)ı s6 44 ��� 50 (44 ��� 61)ı r2 42 ��� 43 (40 ��� 50)ı r3 50 ��� 51 (46 ��� 61)ı r4 41 ��� 44 (50 ��� 65)ı r5 52 ��� 53 (50 ��� 61)ı r6 36 ��� 38 (40 ��� 51)ı J1 40 ��� 41 (40 ��� 55)ı J2 42 ��� 43 (42 ��� 50)ı J3 39 (38 ��� 48)ı J4 39 ��� 40 (40 ��� 57)ı J5 17 (19 ��� 27)ı Z1 43 ��� 44 (38 ��� 55)ı Z2 44 ��� 49 (40 ��� 53)ı Z3 39 ��� 40 (36 ��� 53)ı Z4 37 ��� 39 (36 ��� 57)ı Z5 72 ��� 73 (63 ��� 95)ı S1 39 ��� 41 (42 ��� 55)ı S2 42 ��� 44 (44 ��� 63)ı S3 41 ��� 43 (33 ��� 34)ı S4 42 (42 ��� 59)ı S5 31 ��� 35 (34 ��� 50)ı R 1 32 ��� 34 (36 ��� 46)ı R 2 36 ��� 37 (36 ��� 46)ı R 3 35 (38 ��� 48)ı R 4 36 ��� 35 (36 ��� 55)ı R 5 35 ��� 37 (36 ��� 44)ı R 6 32 ��� 35 (36 ��� 46)ı UR1���UR3 32 ��� 35 (34 ��� 48). Idiosomal venter (Figures 2 and 5 (b)). Tritosternum with trapezoidal baseı 15 (15 ��� 19) longı 15 (13 ��� 15) wide at baseı laciniae piloseı fused for about fourth of total length 17 (17 ��� 19)ı their free parts 45 (44 ��� 48) long. Pre-sternal area transversely lineateı without platelets. Sternal shield fused with endopodal strips of coxae I/II and coxae II/III; 108 (103 ��� 109) long along midlineı 172 (168 ��� 189) wide at level of endopodal projections between coxae I/IIı 157 (158 ��� 164) wide at level of endopodal projections between coxae II/IIIı 95 (97 ��� 91) wide at narrowest interval about mid-level of coxae II; with three pairs of setae (st1���st3) (37 ��� 41 (36 ��� 46) long)ı two pairs of poroids (iv1, iv2) and gland pores gvb; poroids iv1 positioned posteriad seta st1 ı poroids iv2 positioned between setae st2 and st3 ı gland pores gvb positioned on apex of endopodal projections between coxae I and II; posterior margin weakly concaveı arched to level of bases of setae st3; reticulated over all of surface except posteriorly where overlapped by hyaline flap of epigynal shield. Setae st4 (38 ��� 40 (38 ��� 42) long) located on tiny metasternal platelets with greatest dimension only about twice diameter of setal alveolus; poroids iv3 absent. Anterior margin of epigynal shield broadly roundedı overlapping posterior sternal shield areaı extending to level of setae st2 ı posterior margin of shield slightly rounded; epigynal shield reticula outline about 10 elongate cells between bases of setae st5; epigynal shield 180 (181 ��� 185) longı with greatest width of hyaline anterior part 102 (105 ��� 118)ı greatest width of posterior part 77 (76 ��� 84); length st5 34 (34 ��� 38); poroids iv5 placed on soft cuticle closely beside shield. Postgenital platelets absent. Free endopodal plates strongly formed between coxae III and IV. Anal shield ovalı slightly reticulateı with anterior margin roundedı usually indented mediallyı posterior margin nearly truncate; 91 (90 ��� 105) long and 76 (76 ��� 82) wide; anus located slightly anterior to mid-level of shieldı anal opening 33 (34 ��� 40) long; cribrum well-developed; one pair of gland pores present (gv3); length of para-anal setae 21 (21 ��� 23)ı length of post-anal seta 47 (48 ��� 61). Posteriad coxae IV two pairs of elongate metapodal platelets present; the larger platelet 21 (21 ��� 23) longı 7 (6 ��� 8) wide; the smaller platelet 11 (6 ��� 11) longı 5 (3 ��� 5) wide. Soft cuticle around anal shield with 12 ��� 13 pairs of setae (JV1���JV5, ZV1���ZV5 ı flanked by two or three pairs of UR setae) and five pairs of distinguishable poroids. All ventral setae simple; length of setae of JV-, ZV - and UR -series 27 ��� 36 (27 ��� 44) (excluding JV5 60 (61 ��� 84)). Exopodal platelets of coxae II ��� IIIı coxae III ��� IV and platelet enveloping coxa IV posteriorly fused into a single stripı bearing gland pores gv2 at posteromedial extremity. Peritrematal shields fused with dorsal shield at level of setae s1; with four pairs of distinguishable pore-like structures (poroids ip2, ip3 ı and gland pores gp2, gp3); peritreme extending slightly anteriad of setae s1. Spermathecal apparatus not distinguishable. Gnathosoma (Figure 3 (a���f) and 5(c)). Epistome triramousı with medial tine slightly serrated apicallyı longer than lateral tinesı these serrated along their outer margins (Figure 3 (a ��� c) and 5(c)). Subcapitulum 99 (101 ��� 109) wide at widest level. Deutosternum with seven rows of denticlesı rows 1 ��� 5 connected; anterior four rows each with three to eight denticlesı 5th row widenedı concave mediallyı with 10 ��� 15 denticlesı 6th row freeı widenedı with 10 ��� 17 denticlesı 7th row freeı with four to eight denticles (Figure 3 (d)). Hypostome with four pairs of simple setae; palpcoxal seta (pc) 19 ��� 20 (17 ��� 21)ı hp1 28 ��� 29 (27 ��� 32)ı hp2 20 (15 ��� 16)ı hp3 35 ��� 37 (34 ��� 38). Corniculi 29 ��� 34 longı 8 ��� 11 wideı symmetricalı horn-likeı sclerotisedı with paraxial process near base; internal malae slenderı extending to apex of corniculi; salivary styli with blunt apices not reaching tips of corniculi. Palp length from trochanter to tarsus apex 148 ��� 150 (145 ��� 158); setal formula normal: 2 ��� 5 ��� 6 ��� 15 ��� 16; palpfemoral seta al ı palpgenual setae al1 and al2 spatulateı palptarsal apotele 2-tined (Figure 3 (dı e)). Second cheliceral segment length 88 ��� 90 (90 ��� 101)ı movable digit length 36 (36 ��� 42). Fixed cheliceral digit with 17 (16 ��� 20) similar small teethı offset subapical tooth in addition to apical hookı and membranous lobeı distal process absentı antiaxial lyrifissure and dorsal seta distinct; movable digit with three teeth in addition to apical hookı and ventral projection (Figure 3 (f)). Legs (Figures 4 (a���d) and 5(d)). Lengths: I 410 ��� 420 (419 ��� 446)ı II 332 ��� 339 (353 ��� 409)ı III 364 ��� 373 (372 ��� 428)ı IV 469 ��� 476 (476 ��� 530). Leg chaetotactic formulae normal for genus: leg I: coxa 2ı trochanter 6 (1 0/1 1/2 1)ı femur 12 (2 3/1 2/2 2)ı genu 13 (2 3/2 3/1 2)ı tibia 13 (2 3/2 3/ 1 2); leg II: coxa 2ı trochanter 5 (1 0/1 0/2 1)ı femur 11 (2 3/1 2/2 1)ı genu 11 (2 3/1 2/1 2)ı tibia 10 (2 2/1 2/1 2); leg III: coxa 2ı trochanter 5 (1 0/1 0/2 1)ı femur 6 (1 2/1 1/0 1)ı genu 9 (2 2/1 2/1 1)ı tibia 8 (2 1/1 2/1 1) lacking pl2; leg IV: coxa 1ı trochanter 5 (1 0/1 0/2 1)ı femur 6 (1 2/1 1/0 1)ı genu 9 (2 2/1 3/0 1)ı tibia 10 (2 1/1 3/1 2). Tarsi II-IV: 18 (3 3/2 1/1 3/2 3). Tarsus I with erect middorsal macroseta 48 (53 ��� 61) long; tarsus IV with two erect macrosetaeı ad2 70 ��� 71 (74 ��� 101) and pd2 79 ��� 85 (99 ��� 122); all setae smooth. Etymology. The specific name of the new species is derived from the Latin word insolitus ı meaning ���unusual��� ı and refers to the absence of the distal flangelike process of the fixed chela of its female. Differential diagnosis Mucroseius insolitus sp. nov. differs from all known congeners by the absence of the distal flangelike process of the female fixed chela. The following keyı modified from that of Lindquist and Wu (1991) ı further distinguishes the new species from others in the genus. Key to adult females of Mucroseius (based on Lindquist and Wu 1991) 1. Tarsus IV with 2 macrosetaeı pd2 and ad2 ı distinguished by nearly perpendicular orientation and greater length from other tarsal setae........................................................ 2 ��� Tarsus IV with 1 macrosetaı only pd2 readily distinguished as such............................ 7 2. Fixed chela with broadly rounded distal flange; tibia III with 9 setae (pl2 present); dorsal shield ornamented with conspicuous little ridges and reticula over entire surface................................................................................................................................ M. aciculatus ��� Fixed chela with slenderı bluntly pointed distal flangeı or flange absent; tibia III with 8 setae (pl2 absent); dorsal shield smooth or reticulateı not carinulate...................... 3 3. Fixed chela without distal flange............................................................ M. insolitus sp. nov. ��� Fixed chela with slender distal flange.......................................................................................... 4 4. Epistome weakly triramousı its median process broadı untapered and conspicuously serratedı and its lateral processes weakly projected and conspicuously serrated; dorsal shield with setae s4 nearly as long or longer than caudal setae Z5; leg IV with anterior macroseta subequallyı or within 15 ��m as long ası posterior macroseta.. M. disparisetus ��� Epistome clearly triramousı its medial process tapering to a slightly serrated or smooth pointı and its lateral processes well projected and sparsely serrated; dorsal shield with setae s4 usually not more than 0.8 as long as caudal setae Z5 (some M. algonquian excepted); leg IV with anterior macroseta clearly (by 20 ��� 30 ��m) shorter than posterior macroseta........................................................................................ 5 5. Dorsal shield smooth over most of surfaceı with 7 ��� 9 pairs of marginal setae (r2���r6, R 1��� R 2 ı sometimes R 3��� R 4) inserted on its lateral edges; epigynal shield reticula outline 12 ��� 16 finely elongate cells between bases of setae st5; sternal shield with posterior margin deeply excavated to level of setae st2............................... M. nipponensis ��� Dorsal shield smooth or reticulated over most of surfaceı with only 2 or 3 pairs of marginal setae (r2���r3 ı sometimes r4) inserted on its lateral edges; epigynal shield reticula outline 9 ��� 11 elongate cells between bases of setae st5; sternal shield with posterior margin deeply excavated or not................................................................................ 6 6. Dorsal shield conspicuously reticulate over most or all of surface (sometimes smooth medially from setae j4 to j6 ı and from J1 to J4); sternal shield with posterior margin often deeply excavated to level of setae st2 or poroids iv2 ı occasionally this margin remaining weakly evident at level of setae st3.................................................. M. algonquian ��� Dorsal shield mostly unornamentedı smooth over most of surface (lightly reticulated along anterolateral marginsı and sometimes midlaterally between setae j6���J2 and z6���Z2 and caudally); sternal shield with posterior margin gently concave to level of setae st3........................................................................................................................ M. monochami 7. Dorsal shield strongly ornamentedı squamateı over entire surface; 8 or 9 pairs of marginal setae (r2���r6, R 1��� R 3 ı sometimes R 4) inserted on lateral edges of dorsal shield; sternal shield with posterior margin deeply excavated to level of setae st2............................ M. squamosus ��� Dorsal shield unornamented over most of surface; 3 ��� 6 pairs of marginal setae (r2���r4 ı sometimes r5���r6 ı rarely R 1 or R 2) inserted on lateral edges of dorsal shield; sternal shield with posterior margin gently concave to level of setae st3................................ 8 8. Anal shield with anterior margin flattened medially; dorsal shield usually lacking one or both setae of pair z3 ı and with setae J1 and J2 extending slightly beyond bases of J2 and J3 ı respectively.................................................................................................. M. californicus ��� Anal shield with anterior margin smoothly rounded medially; dorsal shield with both setae of pair z3 presentı and with setae J1 and J2 barely or not quite extending to bases of J2 and J3 ı respectively............................................................................ M. mexicanus Remarks Table 1 presents a list of species of the genus Mucroseius with their distribution and hosts. Key to adult females of Mucroseius (based on Lindquist and Wu 1991) 1. Tarsus IV with 2 macrosetaeı pd2 and ad2 ı distinguished by nearly perpendicular orientation and greater length from other tarsal setae........................................................ 2 ��� Tarsus IV with 1 macrosetaı only pd2 readily distinguished as such............................ 7 2. Fixed chela with broadly rounded distal flange; tibia III with 9 setae (pl2 present); dorsal shield ornamented with conspicuous little ridges and reticula over entire surface................................................................................................................................ M. aciculatus
Published as part of Trach, Viacheslav A., Khaustov, Alexander A. & Lindquist, Evert E., 2019, A new unique species of Mucroseius Lindquist�� 1962 (Acari: Mesostigmata: Melicharidae) mites associated with sawyer beetles (Cerambycidae: Monochamus Dejean�� 1821) from the Palaearctic Region, pp. 761-778 in Journal of Natural History 53 (13) on pages 764-769, DOI: 10.1080/00222933.2019.1606954, http://zenodo.org/record/3675600
{"references":["Lindquist EEi Wu KW. 1991. Review of mites of the genus Mucroseius (Acari: Mesostigmata: Ascidae) associated with sawyer beetles (Cerambycidae: Monochamus and Mecynippus) and pine wood nematodes [Aphelenchoididae: Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle] i with descriptions of six new species from Japan and North Americai and notes on their previous misidentification. Can Entomol. 123: 875 - 927."]}