Porohalacarus Thor, 1922

Bartsch, Ilse, 2015, The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification, Zootaxa 3919 (2), pp. 201-259 : 226

Porohalacarus Thor, 1922

Type species. Halacarus alpinus Thor, 1910 .

Adults. Anal and genital plate in female separated ( P. alpinus ) or fused ( P. gallicus ) ( Angelier 1952: fig. 2; Green 1954: fig. 2A; Bartsch 2006c: fig. 5–10a, fig. 5–11b). GP with 4–15 pairs of slender pgs but no sgs. GO in posterior part of GP. Each genital sclerite with three to nine external acetabula. Ovipositor short, at rest slightly extending beyond GO. Basal pair of genital spines smooth, ten apical spines wide, bifid. Apical spines arranged in two anterior and three posterior pairs ( Bartsch 1973b: fig. 8). Male GP and anal plate contiguous or fused. GP with 10–40 pairs of pgs. GO slightly removed from posterior margin of GP. Three to six pairs of external gac situated either on genital sclerites (?) ( Migot 1926: fig. 2;) or posterior to GO ( Bartsch 2006c: fig. 5–10b). Genital sclerites with single pair of sgs. No epimeral pores present.

Juveniles. With one larval and two nymphal stages. In nymphs genital and anal plate separated. GP of deutonymph with two to seven pairs of external gac, two pairs of pgs but no sgs ( Bartsch 1973b: fig. 9). GP of protonymph with two, rarely three pairs of external gac; pgs and sgs not developed. Larva with epimeral pores ( Bartsch 1973b: fig. 11).

Remarks. A freshwater genus which at present includes two species, one seems to be restricted to European waters, the other to be a cosmopolitan ( Bartsch 2009a). Most records are from surface waters (lakes, ponds, ditches).