Leioseius Berlese
Creators: name: De Moraes, Gilberto J.
name: Britto, Erika P. J.
name: Mineiro, Jefferson L. De C.
name: Halliday, Bruce
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Mesostigmata
Ascidae
Leioseius

description: Leioseius Berlese
FEMALE
Gnathosoma. Anterior margin of epistome with three smooth, pointed or distally denticulate projections (two smooth projections in L. californicus Chant). Usually h3 the longest, followed by h1, pc and h2 setae; insertion of h2 about in transverse line or slightly anterior to insertion of h3. Inner palp trochanter seta longer than outer seta but not elongate. Deutosternum relatively narrow (apparently very narrow in L. littorale Womersley), with delimiting lateral lines and seven (six in L. mirabilis Nikolsky) rows of 2–6 denticles each (8–10 in L. basis Karg). Corniculi 1.5–2.5 times as long as their basal widths, with pointed tips, subparallel to slightly divergent distally. Palp tarsal apotele two-tined. Cheliceral digits of similar lengths; fixed digit usually with 3–10 teeth in addition to apical tooth; movable digit with two teeth in addition to apical tooth, without ventral projection.
Idiosoma. Elongate. Dorsum: podonotal and opisthonotal shields fused, smooth to strongly ornamented, usually with distinct lateral incisions at region of fusion (without incisions in this region, but with shallow incision immediately posterior to S 1 in L. basis), without transverse and nearly straight lines, delineated strip along lateral margins or posterior tubercles; anterior end of dorsal shield not strongly deflexed. No supernumerary setae on dorsal shield or on unsclerotised lateral cuticle. Podonotal region of shield usually with 17–18 pairs of setae (19, 20 or 22 pairs in some species); s2 usually inserted on unsclerotised lateral cuticle; r3 inserted on dorsal shield or on unsclerotised cuticle, similar to neighbouring setae or longer and/or more perpendicular to surface of idiosoma than neighbouring setae. Opisthonotal region of shield with 15 pairs of setae (16 pairs in L. basis). Unsclerotised lateral cuticle with 9–12 pairs of setae (2–5 pairs in an undescribed species from Brazil; four pairs in L. littorale); UR setae absent. Most dorsal and lateral setae of idiosoma of similar lengths, short (often Z5 and less often other posterior setae of opisthosoma distinctly longer than other setae), acicular and smooth. Vent er: 0–1 pair of presternal platelets, fused or not with sternal shield. Sternal shield with 2–3 pairs of setae of similar lengths (st1–st3; st1 occasionally inserted on presternal platelets or unsclerotised presternal area; st2 absent in L. californicus Chant) and three pairs of lyrifissures (iv1–iv3; the latter on truncate to concave posterior shield margin); st2 about equidistant to st1 and st3. Seta st4 inserted on unsclerotised cuticle (in the original description of L. naglitschi Karg, shown on metasternal plates). Genital shield distinctly broadened posteriorly, including st5 but usually not iv5 (including iv 5 in an undescribed species from Brazil); posteriorly truncate to slightly convex. One or two pairs of metapodal plates (three pairs in L. brevisetosus Ishikawa). Usually 1–3 pairs of elongate platelets or a sclerotised line between genital and anal shields. Opisthogaster with 8–10 pairs of setae in addition to circumanal setae (seven pairs shown in the original description of L. changbaiensis Yin & Bei), 2–6 pairs of which on ovoid, rounded to subtriangular ventrianal shield; para-anal setae inserted between levels of posterior margin and mid-length of anal opening, from about as long as to about one-fifth as long as post-anal seta, the latter not stout (except in L. australis Luxton). Anal opening small, 1/4 to 1/7 of shield length, in shield centre or posterior to it, away from the posterior shield margin. Anterior section of endopodal shield normally developed and fused with sternal shield; section behind sternal shield usually reduced to an elongate platelet beside coxa IV (not shown in the original description of some species). Exopodal shield usually fragmented at several places along coxae II–IV.
Peritreme. Extending from stigma to region between levels of j2 and z1, about as wide as diameter of stigma. Peritrematic shield wide, fused with dorsal shield at level between z1 and s1 and extending posteriorly around coxa IV, fused or not with exopodal shield, and in some cases also fused to posterior remnant of exopodal shield.
Legs. All legs with pretarsi. Median section of pulvilli of legs II–IV rounded; paradactyli of these legs elongate and acuminate. Setation of legs I–IV, genu: 13 (or 12), 11, 8 (or 9), 9; tibia: 13 (or 12), 10, 8, 10. Leg II not distinctly different from other legs. Legs without macrosetae.
MALE
Gnathosoma similar to female, but movable digit with one tooth in addition to apical tooth; spermatodactyl about as long as or slightly longer than movable digit, directed forward, tapering or tubular, almost straight, curved distally or sinuous. Dorsal shield ornamentation similar to female, but shield slightly broader, including a few more r - R setae. Without presternal platelets. Sternogenital shield with five pairs of setae (st1–st5) and three pairs of lyrifissures (iv1–iv3); not fused with ventrianal or peritrematic shields; posterior margin truncate. Endopodal shield fused with sternogenital shield beside coxae I–III, separated from the shield between coxae III–IV. With two pairs of platelets between genital and ventrianal shields. Without metapodal plates. Ventrianal shield shaped as a broad triangle, covering most of opisthogastric surface, bearing 6–8 pairs of setae in addition to circumanal setae; with 0– 1 pairs of opisthogastric setae on unsclerotised cuticle. Peritreme similar to female. Legs without spine-shaped setae.
description: Published as part of De Moraes, Gilberto J., Britto, Erika P. J., Mineiro, Jefferson L. De C. & Halliday, Bruce, 2016, Catalogue of the mite families Ascidae Voigts & Oudemans, Blattisociidae Garman and Melicharidae Hirschmann (Acari: Mesostigmata), pp. 1-299 in Zootaxa 4112 (1) on pages 25-26, DOI: 10.11646/zootaxa.4112.1.1, http://zenodo.org/record/399477