Description & Statistics
The subfamily is small, members provisioning their nests with Homoptera. The behavior of Psen barthi Vier., that provisions its nest with adult leafhoppers, was studied by Barth (1907). The latter are grasped by the neck or thorax with the middle legs and held with the venter or side up, when being carried to the nest. The nest is situated in an old log and comprises a small number of cells, in each of which 3-5 leafhoppers are placed, the latter probably being killed by stinging during capture. The egg is attached to the thorax of one of the leafhoppers in the cell. Williams (1919c) recorded similar behavior in Nesomimesa hawaiiensis Perk. Clausen (1940) noted that P. pallidipes Panz. (= atratus Panz.) stored its nests with 25-30 paralyzed aphids. Nests are constructed in May, which continues until the season's end.
Finnamore & Michener (1983) considered this group as a subfamily of Pemphredonidae in the Apoidea. Adults tend to construct ground nests, although some species of Psenulus use hollow twigs or stems. Prey consists of Homoptera, usually Cicadellidae, Cercopidae and Fulgoridae, but Membracidae and Psyllidae are also accepted. The subfamily contains ca. 460 species in 11 genera. In North America there are ca. 90 species in 7 genera (25 species, 5 genera in Canada).
Finnamore (1987) analyzed the genera of Pseninae, described a new genus, and keyed the world genera.
Bohart, R. M. y E. E. Grissell. 1969. New species of Psenini (Hymenoptera: Sphecidae ). Pan-Pacific Entomol., 45: 216-221.
Bohart, R.M. y A.S. Menke 1976. Sphecid wasps of the world. A generic revision. Univ. California Press, Berkeley. 695 pp.
Gittins, A. R. 1969. Revision of the Neartic Psenini (Hymenoptera: Sphecidae). I. Redescriptions and keys to the genera and subgenera. Trans. Amer. Entomol. Soc ., 95: 49-76.
Harris, R. A. 1979. A glossary of surface sculpturing. Occas. Papers Entomol., 28: 1-31.
Krombein, K. V. 1950. Taxonomic notes on the wasps of the subgenus Pseneo Malloch (Hymenoptera, Sphecidae). Proc. Entomol. Soc. Washington 52: 277-287.
Malloch, J. R. 1933. Review of the wasps of the subfamily Pseninae of North America (Hymenoptera: Aculeata). Proc. United States Nat. Mus ., 82: 1-60.
Van Lith, J. P. 1975 a . Neotropical species of Psen and Pseneo (Hymenoptera, Sphecidae, Psenini). Tijdschrift voor Entomol., 118: 1- 41.
Van Lith, J. P. 1975 b. New Neotropical species of Pseneo (Hymenoptera, Sphecidae, Psenini). Entomol. Berichten 35: 170-173.