Nudomideopsidae Smith, 1990

Smith, Ian M., Cook, David R. & Gerecke, Reinhard, 2015, Revision of the status of some genus-level water mite taxa in the families Pionidae Thor, 1900, Aturidae Thor, 1900, and Nudomideopsidae Smith, 1990 (Acari: Hydrachnidiae), Zootaxa 3919 (1), pp. 111-156 : 151-152

Family Nudomideopsidae Smith, 1990

Nudomideopsidae Smith, 1990 , pp. 229–251, figs. 1–27.

Nudomideopsidae : Smith & Cook, 1991, pp. 551, 577, figs. 16.82, 16.86–16.88, 16.90, 16.259. Nudomideopsidae : Smith & Cook, 1999, p. 119.

Nudomideopsidae : Smith et al., 2001, pp. 579, 611, figs. 174, 176–179, 385–387. Nudomideopsidae : Walter et al., 2009, p. 270.

Nudomideopsidae : Smith et al., 2010, pp. 522, 553, figs. 15.174, 15.176–15.179, 15.385–15.387.

Diagnosis. Larva (modified from Smith 1983b, 1983c, 1990, and based upon larvae of Nudomideopsis magnacetabula (Smith) and Paramideopsis susanae Smith ): Character states of superfamily Arrenuroidea (see Smith, 1978). Idiosoma nearly round, extremely flattened dorsoventrally. Dorsal plate nearly round, broadly convex anteriorly; bearing four pairs of setae, namely vi, ve, si, and se, anteriorly, with seta si well anterior to midlength of plate. Dorsal plate surrounded by soft integument bearing two pairs of eyes anterolaterally and eight pairs of setae laterally including c1, c2, c3, d1, d2, e1, e2, and f1. Coxal plates on each side all separated by complete suture lines; third coxal plate with transverse muscle attachment scar present. Excretory pore plate subtriangular, attenuate anteriorly and with lateral edges slightly sinuate, bearing setae ps1 anteriorly and ps2 posteriorly. Gnathosoma recessed beneath anterior edge of dorsal plate, with cheliceral bases slender and separate from one another. Pedipalp tarsus bearing seven setae and one solenidion, and with most proximoventral seta thick, bowed, flattened, and fringed basally and most medial seta very thick and fringed. Numbers of setae and solenidia on leg segments as follows: ITi 7 (+ ϕ1 and ϕ2) (setae Ti10 and Ti11 absent); ITa 13 (+ ω); IITi 9 (+ ϕ1 and ϕ2); ITa 13 (+ ω); IITi 9 (+ ϕ1 and ϕ2); IIITa 10 (setae Ta7 and Ta8 absent).

Adults (modified from Smith 1990): Character states of superfamily Arrenuroidea (see Cook 1974a). Idiosoma nearly round to elongate oval in shape; convex or flattened dorsally, convex ventrally. Dorsal and ventral shields entire and separate from one another, with smooth and finely punctate surfaces. Dorsal shield bearing postocularia and three pairs of glandularia. Ventral shield incorporating coxal plates and with first coxal plate not extending to anterior edge of shield, extending to or just beyond anterior edge of shield, or extending well beyond anterior edge of shield; suture line between third and fourth coxal plate ending medially on posterior coxal group so that fourth plate has an extensive medial edge, posteromedial on posterior coxal group so that fourth plate has only a medial angle, or posteriorly on posterior coxal group so that fourth plate does not reach medial edge; fourth coxal plate bearing small projection that partially or completely covers opening for insertion of fourth leg, with suture line at posterior edge distinct or obliterated. Coxoglandularium I located anteriorly in second coxal plate, coxoglandularium II located between fourth coxal plate and genital field. Ventral shield bearing one additional pair of glandularia near posterolateral edges of fourth coxal plates and paired groups of two long, closely-spaced setae associated with a gland that may be reduced in size posterolateral to genital field. Genital field bearing three to many (about 23) pairs of acetabula that are free in gonopore (males and most females) or embedded in ventral shield (some females); gonopore of females extremely large. Pedipalp tibia stocky and slightly expanded ventrally or relatively elongate, slender and slightly constricted basally; bearing two slender setae ventrally. Legs of males with segments unmodified.

Genera included. Allomideopsis Smith, 1990 (stat. nov.), Neomideopsis Smith, 1983 , Nudomideopsis Szalay, 1945 , Paramideopsis Smith, 1983 .

Distribution. Holarctic (Eurasia, North America), New Zealand.

Proposed changes. Elevation of Allomideopsis Smith, 1990 from a subgenus of Nudomideopsis Szalay, 1945 to full generic status.

Discussion. Smith (1990) proposed the family Nudomideopsidae based on an assessment of adult and larval character states of known species of the Holarctic genus Nudomideopsis and related Nearctic genera that strongly indicated that they represent an ancient taxon not closely related to members of the family Mideopsidae . This treatment was supported by the discovery of several species of the clade in New Zealand ( Cook 1983, 1992), and was followed by Smith & Cook (1991, 1999), and Smith et al. (2001, 2010). Here we propose elevation of the ranking of the distinctive taxon Allomideopsis from a subgenus of Nudomideopsis to full generic status.