Forelia Haller, 1882

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 : 116

Genus Forelia Haller, 1882

Forelia (in part): Cook, 1974a, p. 287, figs. 1208–1213.

Forelia (in part): Smith, 1976, pp. 27–30, 79–80, 90–92, figs. 15–20, 23–31.

Forelia: Wainstein, 1980 , pp. 201–204, figs. 694–707.

Forelia (in part): Smith & Cook, 1991, pp. 554, 576, 578, figs. 16.168–16.170, 16.174, 16.177, 16.260, 16.274. Forelia (in part): Smith et al., 2001, pp. 581, 612, 615, figs. 132–136, 338–340. Forelia (in part): Smith et al., 2010, pp. 524, 553, 556, figs. 15.132–15.136, 15.339–15.341.

Diagnosis. Larva (modified from Smith 1976): Character states of the subfamily Foreliinae. Lateral coxal apodeme either nearly parallel to anterior edge of second coxal plate or nearly transverse. Third coxal plate with medial coxal apodeme present and transverse muscle attachment scar present or absent. Excretory pore plate much larger than excretory pore and roughly circular or triangular in shape with setae ps1 at least slightly anterior to setae ps2; excretory pore sessile. Numbers of setae on leg segments as follows: IITi 9, 11 (setae Ti12 and Ti13 present), or 12 (setae Ti12, Ti13, and Ti14 present); IIITr 1; IIITi 9, 11 (setae Ti12 and Ti13 present), or 12 (setae Ti12, Ti13, and Ti14 present).

Adults (modified from Smith 1976): Character states of subfamily Foreliinae. Idiosoma with dorsal and ventral integument mostly soft and bearing only tiny platelets associated with glandularia and idiosomal setae, or bearing larger plates of various shapes that may be coalesced into shields that occupy entire dorsal and ventral surfaces. Fourth coxal plate with medial edge reduced to angle. Genital field with five or more relatively small acetabula per side borne on tongue-shaped acetabular plates that surround gonopore in males and flank gonopore in females, and that may or may not extend laterally beyond posterolateral angles of fourth coxal plates. Pedipalp segments relatively short and stocky, with tibia bearing a sessile, peg-like seta distomedially. Male third leg with tarsus bearing reduced claw sockets that are terminal in position and small but only slightly modified claws; fourth leg with genu unmodified, lacking both thick setae and a proximoventral projection, tibia relatively short, and tarsus curved dorsally, bearing thick, peg-like setae throughout curved portion, and bearing small but relatively unmodified claws.

Type species. Forelia cassidiformis Haller = Forelia variegator (Koch) .

Species included. Numerous species listed by K.O. Viets (1987) but excluding members of Madawaska . There are several undescribed species of Forelia from North America in the Canadian National Collection of Insects and Arachnids.

Distribution. Holarctic.

Discussion. Cook (1974a) and Smith (1976) both included Madawaska as a subgenus of Forelia . Smith (1976) pointed out that species of Forelia belong to a number of distinct groups that differ in a number of larval and adult character states. Some of these groups may be more closely related to other genera of Foreliinae than to each other. Here we consider Forelia and Madawaska as separate genera. As pointed out by Smith (1976), Forelia as currently constituted appears to be polyphyletic and will be subject to further revision when the species level taxonomy of the North American fauna is sufficiently well known to permit the proposal of species groups that are demonstrably holophyletic.