Blattisocius Keegan

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 : 34-35

Blattisocius Keegan

FEMALE

Gnathosoma. Anterior margin of epistome rounded (occasionally only slightly prominent or acuminate) and smooth. Ratio of lengths of hypostomal and pc setae variable; insertion of h2 usually slightly posterior to insertion of h3 (distinctly posterior in B. patagiorum Treat ) and almost in straight diagonal line with h1 and h3. Inner palp trochanter seta not elongate, from slightly longer to slightly shorter than outer palp trochanter seta. Deutosternum narrow, with delimiting lateral lines and usually seven (occasionally six) rows of 1–5 denticles each (sixth row multidenticulate in some species, extending beyond lateral lines; rows not discernible in B. everti Britto, Lopes & Moraes and B. keegani Fox ). Corniculi about 3–4 times as long as their basal widths, very close to each other, distally convergent. Fixed cheliceral digit ranging from similar in length to movable digit much shorter than movable digit; usually with 0–5 teeth in addition to apical tooth (more than ten teeth in B. dolichus Ma ); movable digit with 0–3 teeth (3–4 in B. tarsalis (Berlese)) in addition to apical tooth.

Idiosoma. Oval or ovoid. Dorsum: dorsal shield usually ornamented, usually 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 16–21 pairs of setae; r3 inserted either on dorsal shield or on unsclerotised lateral cuticle, distinguished or not from neighbouring setae by being more perpendicular to the surface. Opisthonotal region of shield with 15 pairs of setae. Unsclerotised lateral cuticle with 9–20 pairs of setae, including some UR setae. Most dorsal and lateral setae of idiosoma of similar lengths, from much shorter to longer than distance to subsequent setae, acicular and smooth; some may be slightly serrate, but none tricarinate. Venter: presternal platelets indistinct, but presternal area usually with transverse lines. Sternal shield with 1–3 pairs of setae (st 1 may be inserted on presternal area; st3 and/or st 4 may be inserted on a platelet connected or not to main body of sternal shield); st1–st3 of similar lengths; st2 about equidistant to st1 and st3 or slightly closer to st2; posterior shield margin usually truncate; occasionally slightly or distinctly concave. Third pair of sternal lyrifissures (iv3) and st4 on unsclerotised cuticle (except both as well as st3 inserted on a platelet narrowly connected to sternal shield in B. dentriticus (Berlese) and B. edentata (Karg) ; iv3 on posterior margin of platelet containing st 3 in B. aegypticus Nasr, Nawar & Afifi ). Genital shield not wide enough to include iv5, but including st5; posteriorly truncate (slightly convex in B. edentata ). One or two pairs of metapodal plates of different shapes. Usually with a sclerotised line between genital and ventrianal shields (a transverse row of narrow platelets in B. mali (Oudemans)) . Opisthogaster with 8–10 pairs of setae in addition to circumanal setae, of which 3–4 pairs on subrectangular to subtriangular ventrianal shield; para-anal setae inserted at level of posterior margin of anal opening or slightly anterior to it (between levels of posterior margin and mid-length of anal opening in B. changjiangensis (Ma)) , shorter or about as long as post-anal seta (much shorter in B. changjiangensis ). Anal opening not enlarged, 1/5 to 1/7 of shield length, separated from posterior shield margin. Anterior section of endopodal shield either well developed and fused with sternal shield or poorly developed; in the latter case, projections between coxae I–II and II–III reduced or absent; section behind sternal shield either indistinct or reduced to an elongate platelet between coxae III–IV. Exopodal shield usually a continuous strip along coxae II–III; occasionally reduced to triangular platelets between coxae II–III and III–IV; always with a separate section beside coxa IV.

Peritreme. Ranging from short, extending to level of posterior margin of coxa III, to long, extending to level of anterior margin of coxa I; narrower than diameter of stigma. Peritrematic shield very narrow, fused with dorsal shield near level of s1–s2, tapered posteriorly and fused with remnant of exopodal shield beside coxa IV. Legs. Median section of pulvilli of legs II–IV rounded. Setation of legs I–IV, femur: 12, 11, 6, 6; genu: 13, 11, 9, 9; tibia: 13, 10, 8, 10 (in B. apisassociae Chinniah & Mohanasundaram , setation described as: femur: 8, 8, 6, 3; genu: 11, 8, 8, 10; tibia: 10, 10, 6, 10). Leg II not thickened, without spine-shaped setae. Leg IV with or without macrosetae.

Spermathecal apparatus. Phytoseiid-type.

MALE

Gnathosoma similar to female, but corniculi more widely spaced, fixed cheliceral digit with 0–10 teeth in addition to apical tooth and movable digit with 0–1 tooth in addition to apical tooth; spermatodactyl usually longer than movable digit, slightly curved downward, with pointed subapical projection on ventral surface. Dorsal shield with ornamentation similar to female, but usually broader, including a larger number of r - R setae ; in some species with fewer dorsal setae on the idiosoma than in female. Presternal platelets absent. Sternogenital shield usually with four pairs of setae (st1–st4; st1 off sternal shield in B. mali ; st5 on sternal shield in B. dentriticus and B. mali ) and three pairs of lyrifissures (iv1–iv3); posterior margin convex; not fused with ventrianal or peritrematic shields. Endopodal shield fused with sternogenital shield (some species with a pronounced constriction behind st4, suggesting an atrophy of endopodal shield in this region). Ventrianal shield subtriangular, larger than in female, bearing 5–6 pairs of setae in addition to circumanal setae. Metapodal plates absent. Cigar-shaped accessory peritrematic structure (narrow transversely ridged strip anterior to stigma) present or absent. Peritrematic shield fused with remnant of exopodal shield beside coxa IV. Legs as in female.