Zercoseius 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 : 45-46

Zercoseius Berlese

FEMALE

Gnathosoma. Anterior margin of epistome with three distally denticulate projections. Seta h1 about as long as h3 and longer than the subequal h2 and pc; insertion of h2 slightly anterior to insertion of h3. Inner palp trochanter seta longer than outer seta but not elongate. Deutosternum wide, with delimiting lateral lines diverging posteriorly and with seven rows of 12–20 denticles each. Corniculi about twice as long as their basal widths, well separated from each other, subparallel. Cheliceral digits of similar lengths, slightly elongate; fixed digit with five teeth in addition to apical tooth; movable digit with two teeth in addition to apical tooth.

Idiosoma. Ovoid. Dorsum: dorsal shield ornamented, without lateral incisions at region of fusion or delineated strip along lateral margins; anterior end of dorsal shield not strongly deflexed, although extending to anterior margin of idiosoma, with j1 inserted at the edge of the shield and directed forward. No supernumerary setae on dorsal shield. Podonotal region of shield with 19 pairs of setae (including all present r setae ; z1, s1, s2 and r2 absent); r3 longer than neighbouring setae and about perpendicular to shield margin. Opisthonotal region of shield with 15 pairs of setae. Unsclerotised lateral cuticle with a pair (R1) of setae. Most dorsal setae tricarinate and strongly pilose. Venter: a pair of presternal platelets present. Sternal shield with three pairs of setae (st1–st3); st2 about as long as st3, longer than st1; st2 about equidistant to st1 and st3; posterior shield margin concave. Third pair of sternal lyrifissures (iv3) and st4 inserted on metasternal plates. Genital shield wide enough to include iv5 or st5; posteriorly truncate. Without metapodal plates. Without distinct platelets between genital and ventrianal shields, which are very close to each other. Opisthogaster with six pairs of setae in addition to circumanal setae, all of which on broad, semicircular ventrianal shield that covers most of the opisthogastric region; para-anal setae inserted between levels of anterior margin and mid-length of anal opening, slightly longer than post-anal seta. Anal opening not enlarged, about 1/6 of shield length, separated from posterior shield margin. Anterior section of endopodal shield fused with sternal shield; section behind sternal shield reduced to elongate platelet between coxae III–IV. Exopodal shield distinct between coxae I–IV.

Peritreme. Extending from stigma to region immediately behind j1, slightly narrower than diameter of stigma. Peritrematic shield very wide, broadly fused with dorsal shield at level of r3 and with exopodal shield beside coxa IV; nearly truncate posteriorly.

Legs. Median section of pulvilli of legs II–IV rounded. Setation of legs I–IV, genu: 13, 11, 10, 9; tibia: 13, 10, 9, 10. Leg II not thickened, without opposable spine-shaped setae on ventral surface. Tarsus I with a conspicuously clavate, recurved dorsodistal seta, about half as long as tarsus. Basifemur only half as wide as telofemur from side view.

Spermathecal apparatus. Not exactly fitting either laelapid- or phytoseiid-type (see Athias-Henriot, 1967).

MALE

Gnathosoma similar to female, but corniculi narrower, more widely spaced and distally divergent, and movable digit with one tooth in addition to apical tooth; spermatodactyl tubular, slightly longer than movable digit, slightly curved and with a distolateral acute extension. Dorsal shield ornamentation similar to female. With a pair of presternal plates. Sternogenital, peritrematic-exopodal and ventrianal shields fused, constituting a holoventral shield, but line of fusion of ventrianal with peritrematic-exopodal shields distinct. Legs similar to female.