Reprinted from: Cockerell,T.A. 1903. New American hymenoptera, mostly of the genus Nomada. Ann. Mag. Nat. Hist. 64(3): 207-208
$ .—Length about 8 millim.
Dark ferruginous, with black markings ; no yellow anywhere.
Mandibles simple. Resembles JSf. Astori, but
certainly a different species, readily distinguished by having
no yellow at lower corners of face ; having the third antennal
joint at least as long as the fourth ; the sides of the dark red
abdomen without black marks, and the surface of the abdomen
very distinctly punctured, which is not at all the case in
Astori. Maxillary palpi with the fourth joint longest, but
the third almost as long ; the fifth and sixth very slender
the fifth conspicuously shorter than the fourth and the sixth
than the fifth. Face with short white hair; occiput with
tawny hair ; scape black above apically ; front and region of
ocelli suffusedly blackened ; mesothorax with a single broad
median black stripe ; scutellum and postscutellum dark red
but metathorax black ; tegulse shining coppery red, with very
sparse punctures. Wings fairly clear, the broadly darkened
apical margin strongly contrasting ; stigma very dark reddish,
nervures piceous ; second submarginal cell broad above. Legs
red, with little black, but the middle femora at base and the hind femora behind are conspicuously blackened ; hair on
inner side of basal joint of hind tarsi pale golden ; a trilobed
black mark at base of first abdominal segment.
Hab. Corvallis, Oregon, May 24.
Received from Mr. Viereck.
Mr. Viereck has called my attention to a character of the
venation which is useful for separating closely similar species
of Nomada. Applied to the species above described it gives
these results :
(1) Transverso-medial nervure joining discoidal
nervure some distance from its base * N. Clarkii, N. Grayi,
N. oregonica.
(2) Transverso-medial nervure joining discoidal
nervure very near to or at its base N. Leivisi, N. Astori,
N. corvallisensis, N.
ultima, N. erythrochroa,
N. Foivleri.
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