Eotetranychus Oudemans, 1931

Zhang, Lanni, 2017, A new Australian species of Eotetranychus (Acari: Tetranychidae) from buck spinifex Triodia mitchelli (Poaceae), intraspecific variation in Eotetranychus, and the synonymy of Platytetranychus with Eotetranychus, Zootaxa 4324 (3), pp. 491-517 : 492-493

Eotetranychus Oudemans, 1931

Eotetranychus Oudemans, 1931: 224 . Type species: Trombidium tiliarium Hermann, 1804 , by original designation (but erroneously referred to as Acarus telarius Linnaeus, 1758 ).

Apotetranychus Oudemans, 1931: 225 . Type species: Apotetranychus muscicola Oudemans, 1931 , by original designation (synonymy by Pritchard & Baker, 1955, p. 138).

Platytetranychus Oudemans, 1931: 224 . Type species: Tetranychus gibbosus Canestrini, 1890 , by original designation (synonymy by Pritchard & Baker, 1955, p. 138).

Diagnosis. Peritreme straight, recurved or anastomosing distally; opisthonotum with 12 pairs of setae (c1–3, d1–2, e1– 2, f1–2, h1–3; n.b. setae h2–3 are often posteroventral); seta f 1 in typical dorsocentral position; dorsal body setae slender, smooth or weakly serrated, usually as long or longer than distance to setal bases in next row; dorsal opisthosoma with mostly transverse striae, with some longitudinal striae laterally; two pairs of genital setae (g1–2); two pairs of pseudanal setae (ps1–2); tarsus I with two pairs of distal, adjacent duplex setae; tarsus II with one pair of duplex setae; empodial claw absent; empodium split into two sets of three proximoventral hairs, with proximal pair of hairs thicker than other two pairs (except often male tarsus I, and sometimes tarsus II, with proximoventral hairs reduced to short teeth, forming a pair short, broad trifid plates, or with middle pair of proximoventral hairs significantly thickened and uncinate, appearing as a pair of “claws” when viewed dorsally); male aedeagus variable in shape, but often tapering.

Remarks. The generic concepts of Gutierrez (1985) and Meyer (1987), expressed in the key to genera presented in Bolland et al. (1998), places Eotetranychus among a group of three other closely related genera, all with their taxonomic histories entangled: Mononychellus , Palmanychus and Platytetranychus . These genera share the complete opisthosomal setation for the Tetranychini (c1–3, d1–2, e1–2, f1–2, h1–3, ps1–2, g1–2, ag), duplex setae on tarsus I distal and adjacent, and females with their empodia split into two sets of three proximoventral hairs but lacking an empodial claw or spur. Eotetranychus is also closely related to Schizotetranychus and differs only in the often subtle morphology of the empodia ( Pritchard & Baker 1955), discussed later. As classifying our new species to genus challenged us, we discuss each of the genera under consideration and their histories with Eotetranychus .