Arctoseiodes Willmann

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 : 17-18

Arctoseiodes Willmann

FEMALE

Gnathosoma. Anterior margin of epistome with three distally denticulate projections. Seta h1 longer than h2, h3 and pc setae; insertion of h2 slightly anterior to insertion of h3. Deutosternum with seven rows of 1–2 teeth each. Corniculi short and strong, with pointed tips. Cheliceral digits of similar lengths; fixed digit with four teeth in addition to apical tooth; movable digit with two teeth in addition to apical tooth, without pointed ventral projection. Idiosoma. Ovoid. Dorsum: podonotal and opisthonotal shields fused, with lateral incisions at region of fusion, 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 with 18 pairs of setae (z3 absent; r5 on shield). Opisthonotal region of shield with 15 pairs of setae (J2 and S1 absent; R3 and R4 on shield). Unsclerotised lateral cuticle with 4–5 pairs (r -R) of setae, including r3, which is similar to neighbouring setae. Dorsal and lateral setae of idiosoma of variable lengths, acicular. Vent er: one pair of presternal platelets present. Sternal shield with three pairs of setae of similar lengths (st1–st3) and three pairs of lyrifissures (iv1–iv3); iv3 on posterior shield margin, which is slightly concave; st2 slightly closer to st3 than to st1. Seta st4 inserted on unsclerotised cuticle. Genital shield not wide enough to include iv5, but including st5; posteriorly convex. Two pairs of metapodal plates, the anterior elongate, the posterior smaller, rounded. Three pairs of platelets between genital and ventrianal shields. Opisthogaster with eight pairs of setae in addition to circumanal setae, of which 2–3 pairs on subquadrate ventrianal shield; para-anal setae inserted at level of mid-length of anal opening, about as long as post-anal seta. Anal opening small, about 1/6 of shield length, behind shield centre, separated from posterior shield margin. Anterior section of endopodal shield fused with sternal shield; section behind sternal shield reduced to an elongate platelet between coxae III–IV. Exopodal shield reduced to plates between coxae I–II, II–III and III–IV.

Peritreme. Extending from stigma to level of z1, slightly narrower than diameter of stigma. Peritrematic shield slender; fused with dorsal shield at level of z1 and with exopodal shield beside coxa IV, extending around posterior and inner margin of coxa to fuse with posterior remnant of endopodal shield.

Legs. All legs with pretarsi. Setation of legs I–IV, genu: 12, 11, 10, 10; tibia: 12, 10, 9, 10. Legs without macrosetae.

MALE

Cheliceral digits of similar lengths; fixed digit with three teeth in addition to apical tooth; movable digit with one tooth in addition to apical tooth; spermatodactyl about twice as long as movable digit, slightly curved and tapered distally. Dorsal shield with ornamentation similar to female, but broader, including r2–r4, R3 and R4. Shape of dorsal setae similar to female. Presternal platelets indistinct. Sternogenital shield with five pairs of setae (st1–st5) and three pairs of lyrifissures (iv1–iv3); posterior margin convex. Endopodal, exopodal and peritrematic shield development and fusion similar to female. Two pairs of elongate platelets between sternogenital and ventrianal shields. Ventrianal shield subtriangular, bearing seven pairs of opisthogastric setae in addition to circumanal setae; not fused with neighbouring shields. Legs without spine-shaped setae.