Scleriacarus Beard & Seeman, 2025, gen. nov.

Scleriacarus gen. nov. Beard & Seeman Type species— Scleriacarus gilberti sp. nov. Beard & Seeman Diagnosis. Adult female. Body moderately elongate, slightly more than twice as long as wide; prodorsal and opisthonotal shields weakly developed. Palps 3-segmented; palp tarsus with 2 terminal phaneres (both long). Anterior margin of prodorsum with short median forked projection forming a notch; dorsal opisthosoma with 9 pairs of setae (c3, d1, d3, e1, e3, f2, f3, h1, h2 present; c1, c2, d2, e2 absent); dorsal setae short, fine with blunt rounded tips; seta h2 not flagellate (flagellate only in larva). Ventral and genital shields not developed, both regions membranous and merged together; two pairs of ps setae, anal valves membranous, setae ps3 inserted far anterior to ps2; ventral setae g1 inserted anterior to g2; 4a1–2 present, elongate, fine; lacking supernumerary coxal setae 3a2. Trochanters 1-1-1-0 (v′ added to tr I–II in deutonymph; l′ added to tr III in protonymph; v′ absent on tr IV); femora 4-4-2-2, femur I with d inserted centrally, broad, barbed (heteromorphic with respect to dorsal idiosomal setae), femur II with d inserted laterally; genua 2-2-0-0 (d absent on ge I–II); tarsi 7(1)-7(1)-5-5, setae ftʺ and tcʺ absent on tarsi I–II, setae ftʹ on tarsi I–IV finely elongate. Tarsal claws and empodia pad-like. Adult male. With solenidion present on tarsi I–IV. Remarks. Of the sedge-associated genera, Scleriacarus gen. nov. appears closest to Acaricis in sharing the same body shape (i.e. not significantly elongate), the same complement of dorsal opisthosomal setae, a forked median prodorsal projection, two pairs of 4a setae, setae g1 inserted anterior to g2, setae ps3 far anterior to ps2, lacking ftʹʹ on tarsi I–II and males with a solenidion on tarsi III–IV (in most species of Acaricis). Scleriacarus differs from Acaricis by having setae h2 unmodified (flagelliform in Acaricis), lacking tcʹʹ on tarsi I–II, having 3- segmented palps (versus 4-segmented in Acaricis), and seta d on femur I in a dorsal position (lateral in Acaricis). The absence of setae ft″ on tarsi I–II is also found in the other sedge-inhabiting genera Cyperacarus, Gahniacarus and Prolixus, but the loss of tcʹʹ is shared only with Cyperacarus and Gahniacarus.