Arrhenoseius Walter & Lindquist

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 : 33-34

Arrhenoseius Walter & Lindquist

FEMALE

Gnathosoma. Anterior margin of epistome with three pointed and smooth projections. Seta pc about as long as h1 and h3, distinctly longer than h2; insertion of h2 slightly posterior to insertion of h3. Inner palp trochanter seta similar in length to outer seta, not elongate. Deutosternum wide, with delimiting lateral lines and seven rows of 14– 30 denticles each, the third row from the base much narrower than others. Corniculi about twice as long as their basal widths, well separated from each other, subparallel. Cheliceral digits of similar lengths; fixed digit with 16– 18 teeth in addition to apical tooth; movable digit with three teeth in addition to apical tooth.

Idiosoma. Hemispheric, almost totally sclerotised, except for a narrow band of unsclerotised cuticle around ventrianal shield and between dorsal and peritrematic shields. Dorsum: dorsal shield strongly reticulate; without lateral incisions at region of fusion or delineated strip along lateral margins; anterior end of dorsal shield not strongly deflexed. No supernumerary setae on dorsal shield. Podonotal region of shield with 22 pairs of setae, including r3, which is distinguished from neighbouring setae by being almost perpendicular to lateral shield margin and smooth. Opisthonotal region of shield with 14 pairs of setae. Unsclerotised lateral cuticle with a pair of setae (R1). Dorsal idiosomal setae mostly elongate, curved, thick, sparsely barbed, except j1, z1 and s2 short, acicular; lateral idiosomal seta smooth. Venter: presternal platelets indistinct. Sternal shield with three pairs of setae of similar lengths (st1–st3); st2 about equidistant to st1 and st3; posterior shield margin deeply concave. Third pair of sternal lyrifissures (iv3) and st4 inserted on metasternal plates. Genital shield broad, including st5 but not iv5; posteriorly truncate. Discrete metapodal plates absent, apparently fused with truncate posterior margin of peritrematic shield. No platelets between genital and ventrianal shields. Opisthogaster with eight pairs of setae in addition to circumanal setae, of which seven pairs on broad, subtriangular ventrianal shield; Jv5 shorter than most opisthogastric setae, inserted on unsclerotised cuticle; para-anal setae inserted at level of mid-length of anal opening, subequal to or slightly shorter than post-anal seta. Anal opening small, about 1/5 of shield length, separated from posterior shield margin. Anterior section of endopodal shield fused with sternal shield; section behind sternal shield abutting internal margin of coxae III and IV. Exopodal shield broad, occupying total area laterad of coxae I–IV and behind coxa IV, abutting posterior end of endopodal shield.

Peritreme. Extending from stigma to region between j1 and j2, slightly wider than diameter of stigma, with crenulated margins. Peritrematic shield wide, fused with dorsal shield at level of s2 and fully fused with exopodal shield along coxae I–IV.

Legs. Median section of pulvilli of legs II–IV rounded. Setation of legs I–IV, genu: 13, 11, 9, 9; tibia: 13, 10, 8, 9. Leg II of female not thickened and without spine-shaped setae. Tarsus I with dorsal subapical sensillus s slightly clavate, strongly recurved distally; pv1 and av2 present on genua II and III; pl2 absent on genu III and tibiae III and IV. Macrosetae present on tarsi II–IV.

Spermathecal apparatus. Phytoseiid-type.

MALE

Gnathosoma similar to female, but corniculi more incurved; fixed digit with 11–12 teeth in addition to apical tooth and movable digit shorter than fixed digit, with one tooth in addition to apical tooth; spermatodactyl T-shaped, about as long as movable digit, directed forward, curving slightly downward. Dorsal shield ornamentation and relative setal lengths similar to female. Idiosomal venter entirely covered by strongly sclerotised holoventral shield consisting of consolidated sternogenital, ventrianal, endopodal and peritrematic-exopodal elements; line of fusion between sternogenital and ventrianal shields sometimes evident. Opisthogaster with only five pairs of setae in addition to circumanal setae. Setation and other leg structures similar to female, with no evident dimorphism.