Lasioseius Berlese

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), Zootaxa 4112 (1), pp. 1-299 : 41-43

Lasioseius Berlese

FEMALE

Gnathosoma. Anterior margin of epistome extremely variable, sometimes even within the same species, with 0–5 anterior projections (most commonly three projections), truncate or convex; smooth, denticulate or with strong spines; rarely projections long and acicular. Ratio of lengths of hypostomal and pc setae variable; most often h1 or h3 the longest and h2 or pc the shortest; insertion of h2 variable in relation to insertion of h3, usually from slightly anterior to slightly posterior (well posterior in L. corticeus Lindquist , L. inguinalis Karg , L. ometisimilis Hirschmann and L. penicilliger Berlese ; well anterior in L. safroi (Ewing)) ; often with a distinct membranous extension of the hypostome near paraxial base of corniculus. Inner palp trochanter seta usually not elongate. Deutosternum usually wide (in some species, relatively narrow) with delimiting lateral lines that are either subparallel to each other or not, connecting all or only the most distal six rows of denticles; with seven rows of usually 2–20 denticles each (sixth row sometimes extending beyond edge of deutosternum). Corniculi usually 1.5– 2.5 as long as their basal widths (up to 3.5 in L. kinikinik Walter & Lindquist and L. penicilliger ), well separated from each other, subparallel (distally convergent in L. athiashenriotae De Leon ). Occasionally with a fringed hyaline rim, with or without teeth along paraxial face of cheliceral shaft, above base of movable digit. Cheliceral digits of similar lengths; fixed digit with four to over 40 teeth (most commonly 12–16) in addition to apical tooth; rarely with a dorsodistal pointed process; movable digit with 2–7 (most commonly three) teeth in addition to apical tooth.

Idiosoma. Oval, ovoid to roundish. Dorsum: dorsal shield ornamented, without lateral incisions at region of fusion; delineated strip along lateral margins rarely present; anterior end of dorsal shield not strongly deflexed (reaching anterior margin of idiosoma, with j1 inserted at the edge of the shield and directed forward in L. frontalis Evans & Sheals ). No supernumerary setae on dorsal shield. Podonotal region of shield with 12–23 pairs of setae, including r3, which is often longer, more perpendicular to shield margin or of different shape in relation to neighbouring setae (in less setose species, j1 absent, and the anteriormost j seta is positioned behind the anteriormost lyrifissure). Opisthonotal region of shield with 10–15 pairs of setae. Unsclerotised lateral cuticle with 1–12 pairs of setae. Most dorsal and lateral setae of idiosoma usually similar in length (distinctly longer and/or differently shaped r3 and posterior setae, especially Z5, than other setae in many species; distinctly shorter J and r - R setae in most species with reduced number of dorsal shield setae; some anterior dorsal shield setae differently shaped in relation to others in L. parabispinosus Kandil and in some specimens of L. allii Chant ), acicular or tricarinate, smooth or serrate, usually shorter than distance to subsequent setae (slightly longer in L. safroi ). Ve n t e r: 0–2 pairs of presternal platelets (each of which may be subdivided). Sternal shield usually with three pairs of setae (st1–st3); occasionally st1 inserted on unsclerotised cuticle or presternal platelets or st3 inserted on unsclerotised cuticle (shield with wide unsclerotised median longitudinal band in L. safroi ); st1–st3 acicular (st1 spine-shaped and arched in L. parabispinatus and in some specimens of L. allii ); st2 about equidistant to st1 and st3 or slightly closer to st3; posterior shield margin from concave to convex. Third pair of sternal lyrifissures (iv3) and st4 usually inserted on metasternal plates (iv3 and st4 inserted on unsclerotised cuticle in several species; iv3 on posterior margin of sternal shield in L. allii and probably also in L. parabispinosus ). Genital shield rarely wide enough to include iv5, but including st5; posteriorly truncate to slightly convex. One or two pairs of round, triangular or elongate metapodal plates (distinctly broad in several species). With 0–3 pairs of platelets or a sclerotised line between genital and ventrianal shields. Opisthogaster usually with 8–9 pairs of setae (occasionally seven or ten pairs) in addition to circumanal setae, of which usually four or six pairs (rarely two, three or five; none in L. quandong Walter & Lindquist ) on a ventrianal shield that varies from very reduced, bearing only circumanal setae and a pair of pre-anal pores, to broad, extending over most of opisthogaster (usually subtriangular, with truncate or convex anterior margin); para-anal setae inserted between levels of posterior margin and mid-length of anal opening, usually as long as or shorter than post-anal seta (a third as long as post-anal in L. cinnyris Fain & Mariaux ), the latter only occasionally stout. Anal opening from small to moderately enlarged, 1/3 to 1/8 of shield length, separate from posterior margin. Anterior section of endopodal shield fused with sternal shield; section behind sternal shield indistinct or reduced to variously developed platelets (sometimes broad) between coxae III–IV (section beside coxae II–III reduced to an elongate, diagonally oriented platelet that may be fused with platelet behind sternal shield in L. elegans Fain, Hyland & Aitken ). Exopodal shield usually a continuous strip between coxae II–IV (interrupted between coxae I–II in L. corticeus and beside coxa IV in L. cinnyris ).

Peritreme. Usually extending from stigma at least almost to level of z1 (rarely shorter), slightly narrower than diameter of stigma; with post-stigmatic extension, much wider than diameter of stigma in L. confusus Lindquist and L. mirabilis Christian & Karg. Peritrematic shield wide, usually broadly fused with dorsal shield at level of s1 and with exopodal shield beside coxa IV.

Legs. Median section of pulvilli of legs II–IV rounded. Setation of legs I–IV, genu: 13 (rarely 12), 11 (rarely 9 or 10), 9 (rarely 7 or 8), 9 (rarely 10); tibia: 13 (rarely 12), 10 (rarely 11), 8 (rarely 9), 10 (rarely 9). Leg II not distinctly thickened. Leg IV commonly (other legs occasionally) with one or more macrosetae. Occasionally with some setae of legs I and II spine-shaped.

Spermathecal apparatus. Phytoseiid-type.

MALE

Gnathosoma similar to female, but corniculi more widely spaced, fixed cheliceral digit with 5–12 teeth in addition to apical tooth and movable digit with 1–4 teeth in addition to apical tooth; spermatodactyl directed forward, about 1.0–1.5 times as long as movable digit (about twice as long in L. quandong ), from almost straight to curved downward, variously shaped but usually simple. Dorsal shield with ornamentation similar to female, but usually slightly broader, including 1–2 additional r - R setae ; with fewer setae on unsclerotised lateral cuticle. Dorsal shield setae occasionally relatively longer or shorter than in female. Presternal platelets present or not. Sternogenital shield with five pairs of setae (st1–st5) and three (iv1–iv3) or four pairs of lyrifissures (iv1–iv4); posterior margin from slightly concave to slightly convex. Endopodal shield fused with sternogenital shield. Metapodal plates absent. Ventrianal shield usually wider than in female and subtriangular, bearing 5–7 pairs of opisthogastric setae in addition to circumanal setae (reduced, with only four pairs of opisthogastric setae in L. angustus Evans & Sheals ); with 0–4 pairs of opisthogastric setae on unsclerotised cuticle. Peritrematic shield fused with exopodal shield beside coxa IV but usually not fused with ventrianal shield (fused in L. quandong ). Leg setation similar to female.