Psen Latreille 1796

Psen Latreille, 1796 Psen Latreille, 1796: 122 (no included species). Type species: Sphex ater Fabricius, 1794 [= Crabro ater Olivier, 1792], designated by Latreille 1802: 338 (first included species). Psenus Rafinesque, 1815: 124. Emendation of Psen Latreille, 1796. Mesopora Wesmael, 1852: 279. Type species: Psen ater of Vander Linden, 1829 [= Sphex ater of Panzer, 1799 = Sphex ater Fabricius, 1794 = Crabro ater Olivier, 1792], by monotypy. Diagnosis. The genus Psen can be identified as a member of the tribe Psenini Costa, 1858 within the subfamily Pemphredoninae based on Mandible bidentate apically; occipital carina joining hypostomal carina before midventral line of head; no genal process; scrobe sulus deep, hypoepimeral area raised; omaulus ending as it becomes ventral and turning a little posteriorly; forewing second recurrent vein ending in second or interstitial or third submarginal cell, hindwing M diverging before cu-a; propodeum usually coarsely reticulate posteriorly, sometimes multivariate; dorso-median area of petiole usually smooth, rarely with coarse punctures, without carinae but rarely with a posterior longitudinal groove, no conspicuous laterodorsal setae but abundant strong setae lateroventrally; male gastral sterna III and IV, or only III or IV, with marginal setae posteriorly, rarely without marginal setae, VIII an upturned pseudo-sting; female pygidial plate subtriangular, narrow or broad, sparsely or densely bristled (Bohart and Menke 1976).