Wasps and Bees 31 g 



Bombus pleuralis (Nyl.) Franklin. 

 Bombus pleuralis Franklin, Trans. Amer. Ent. Soo. XXXVIII, p. 364. 



Male. — Head and thorax clothed with yellow pile; a few black hairs on 

 the inner and outer margins of the eyes and around the ocelli and a well-defined 

 black interaler band. Abdomen with segments 1 and 2 yellow; segments 3 and 

 4 bright red, with a few black hairs at the bases of the segments in one specimen; 

 segments 5 to 7 black, a few red hairs on segment 5; venter mostly pale yellow. 

 Length, 13-14 mm. 



Worker. — Head black with a small patch of yellow between the antennse 

 and extending above them, and another on the vertex. Thorax yellow with a 

 well-defined black interalar band. Abdomen: segments 1 and 2 yellow with, 

 in three specimens, a few dark hairs in the middle, segments 3 and 4 red, 5 and 6 

 variable. Length, 10-12 mm. 



Two males from Nome, Alaska, August 24-25, 1916 (F. Johansen); four 

 workers, Nome, Alaska, August 24-25, .1916 (F. Johansen). 



This is Franklin's "colour variant" of pleuralis. In the red band on the 

 abdomen it approaches flavifrons Cr. and centralis Cr. but is distinguished 

 therefrom by the clear black interalar band and the weak yellow on the face. 

 However, extensive collecting of the three forms in Western Canada by the 

 writer shows that flavifrons and centralis are merely varieties of pleuralis. The 

 name pleuralis is applied by Vogt to one of the forms of the Kirbyellus group. 



Bombus frigidus, Smith. 

 Bombus frigidus, Franklin, Trans. Amer. Ent. Soc. XXXVIII, p. 360. 



Male. — Head and thorax pale yellow, a few black hairs around the margins 

 of the eyes, the insertion of the antennae and the ocelli, and a well-defined black 

 interalar band. Abdomen: segments 1 and 2 pale yellow, segments 3, 4 and 

 base of 5 black. Apex of 5 and remaining segments dingy white with a fer- 

 ruginous tinge, evidently faded. Length, 12J4 mm. 



Worker. — Face black, vertex pale yellow. Thorax pale yellow with a 

 broad black interalar band. Abdomen: segments 1 and 2 pale yellow, segment 

 3, and base of 4, black; apex of segment 4 and remaining segments pale fer- 

 ruginous. Length, 10-11 mm. 



One male, Nome, Alaska, August 24, 25, 1916 (F. Johansen); two workers, 

 Nome, Alaska, August 24, 25, 1916 (F. Johansen). (The Canadian National 

 Collection contains a worker of Bombus mixtus Cr. taken in the Porcupine 

 Mountain district, Yukon Territory, on June 15, 1912, by D. D. Cairnes.) 



Terrestris Group. 

 Terrestris Group, Franklin, Trans. Amer. Ent. Soc. XXXVIII, p. 261. 



Distinguishable from the other groups by its broad face, very short malar 

 space, less than one-fifth as long as the eye, and the very different genitalia of 

 the males. 



Bombus lucorum, L., variety moderatus Cr. 



Bombus terrestris, var moderatus Franklin, Trans. Aoipr. Ent. Soc. XXXVIII, p. 262. 



Worker. — Head black; thorax black, with an anterior pale yellow band. 

 Abdomen: segment 1 black, pale yellow at the sides; segment 2 pale yellow, 

 segment 3 and base of segment 4 black; apex of segment 4 and segments 5 and 6 

 white. Length, 12 mm. 



