Mucroseius Lindquisti 1962
Creators: name: Trach, Viacheslav A.
name: Khaustov, Alexander A.
name: Lindquist, Evert E.
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Mesostigmata
Ascidae
Mucroseius

description: 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 μm 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 μm) shorter than posterior macroseta ........................................................................................ 5
5. Dorsal shield smooth over most of surfaceı with 7 – 9 pairs of marginal setae (r2–r6, R1–R2 ı sometimes R3–R4) 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, R1–R3 ı sometimes R4) 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 R1 or R2) 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
description: Published as part of Trach, Viacheslav A., Khaustov, Alexander A. & Lindquist, Evert E., 2019, A new unique species of Mucroseius Lindquistı 1962 (Acari: Mesostigmata: Melicharidae) mites associated with sawyer beetles (Cerambycidae: Monochamus Dejeanı 1821) from the Palaearctic Region, pp. 761-778 in Journal of Natural History 53 (13) on pages 767-769, DOI: 10.1080/00222933.2019.1606954, http://zenodo.org/record/3675600