Gnathusa Fenyes

Klimaszewski, Jan, Webster, Reginald P., Langor, David W., Bourdon, Caroline, Hammond, H. E. James, Pohl, Greg R. & Godin, Benoit, 2014, Review of Canadian species of the genera Gnathusa Fenyes, Mniusa Mulsant & Rey and Ocyusa Kraatz (Coleoptera, Staphylinidae, Aleocharinae), ZooKeys 412, pp. 9-40 : 12

Gnathusa Fenyes

Gnathusa Fenyes 1909: 197. Type species: Gnathusa eva Fenyes.

Diagnosis.

Body dark brown to black, compact and robust, subparallel (Figs 1a, 2a, b, 3a, 4a), length 3.5-4.3 mm; integument with distinct meshed microsculpture; head large with mandibles extremely long and sickle-shaped, apices very slender, each crossing the other in resting position, each mandible bearing long spine or tooth (Figs 1h, i, 2i, j, 3h, i, 4h, i); infraorbital carina strong and complete; ligula more or less deeply bilobed (Figs 1l, 2m, 3l, 4l); last article of maxillary palpus needle-shaped (Figs 1k, 2l, 3k, 4k); frontal suture of head absent; anterior margin of mesosternum with short V-shaped basal carina, remaining mesosternum uncarinated; mesosternal process long, triangular basally and then narrowly produced and extending to about ¾ length of mesosternal cavities, metasternal process triangular in shape and short, isthmus short; median lobe of aedeagus with large crista apicalis, internal sac structures variable in shape (Figs 1b, 2c, 3b, 4b), paramere with narrowly elongate apical lobe bearing four macrosetae; spermatheca pipe-shaped with spherical or tubular capsule and elongate narrow stem (Figs 1e, 2d, 3e, 4e).

Key to Canadian species of Gnathusa

New provincial and territorial records are indicated in boldface font.