62 Myron Harmon Szuenk 



Nomada (Heminomada) elrodi Cockerell. 



1903. Nomada elrodi Cockerell, Proc. Acad. Nat. .?a. Phil., pp. 583- 



84, c^. 

 1905. Nomada elrodi Cockerell, Bull. 94, Colorado Exp. Sta., p. 73, 



This species was originally described from a type male from 

 Montana and a single male paratype from Cedar Bluffs, Nebraska 

 (L. Bruner, No. 30), and additional specimens have not since 

 been recorded from elsewhere. It is, however, a fairly common 

 species in Nebraska, and the writer has before him a series of 

 four females and eight males collected at Lincoln, Cedar Bluffs 

 and West Point, Nebraska, April 13 to May 19, at flowers of 

 Ribes gracile and Primus americana. A ninth male is from 

 Sierra Blanca, Costilla county, Colorado, July 10, 1907 (L. 

 Bruner). No single one of the series of nine males agrees with 

 the original description in every detail, though one (Lincoln, 

 Nebraska, May 11, 1901, on Ribes gracile, M. A. Carriker) does 

 so except in slightly smaller size (9 mm.) and in having the 

 whole of the mesoscutum black as in the Cedar Bluffs paratype. 

 The series shows the males to be exceedingly variable in the color 

 markings: viz., the supraclypeal mark is sometimes present as 

 in the type, but usually is absent or reduced to a tiny spot; the 

 lateral face marks are sometimes broad above and fill the space 

 between the orbits and supraclypeus as in the type, but usually 

 are narrower though rather broad above and sometimes may even 

 be reduced to mere broadly linear marks terminating in a point 

 at level of insertion of antennae ; the flagellum is usually black 

 spotted behind beyond as well as before the fourth or fifth joint; 

 the lateral borders of the mesoscutum are usually not red ; the 

 pleural mark is usually smaller, v-shaped or round ; the meso- 

 scutellum is sometimes yellow, sometimes has large yellow or 

 red spots and sometimes very tiny yellow or red spots ; the 

 propodeum is sometimes marked as described for the type, some- 

 times 'has only the two spots on the enclosure, but usually is all 

 black; the basal nervure is sometimes a little basad of, sometimes 

 considerably basad of, and sometimes interstitial with the trans- 

 verso-medial ; in size the series varies from 7 to 9 mm. All, how- 



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