194 Psyche [October-December 



could be found, and it is therefore probable that this nest was 

 subterranean. 



In the neighborhood of Boston, Bremus borealis is extremely 

 rare. Most of the queens probably do not appear until late in 

 spring. Three other queens which I captured in 1922 were 

 taken May 29th (on Diervilla), June. 6th (on Rhododendron), 

 and July 2nd (searching for a nesting site). However I have 

 never seen any workers or males of this species near Boston. 



Pratorum Group. 

 I. Bremus bimaculatus Cresson. 



The only nest of Bremus bimaculatus of which we have a 

 record was taken by Franklin (1912/13, I, p. 308) on July 15, 

 1904, at Bernardstown, Mass. It was situated on the surface 

 of the ground, among the bases of saplings, in a thicket of alders, 

 and contained 6 queens, 10 workers, 9 males and a considerable 

 number of cells with partially developed larvae. 



I found 4 nests of this species in, or near, the Arnold 

 Arboretum during the summers of 1921 and 1922. All were 

 subterranean, and from 6 inches to 1 ft. below the surface of the 

 ground, the tunnels varying from 9 inches to 4 ft. in length. 

 One of the shorter-tunneled nests, taken July 3, 1921, was al- 

 most completely destroyed by the larvse of the tachinid fly, 

 Brachycoma sarcophagina Townsend (det. Mr. C. W. Johnson). 

 This nest also contained several thief ants {Solcnopsis molesta 

 Say (det. Dr. G. C. Wheeler). The largest of the 4 nests con- 

 tained (July 8, 1921) the old queen, 23 young queens, over 60 

 workers, and a considerable number of queen cells. 



In the vicinity of Boston, the queens of Bremus bimaculatus 

 appear at about the same time as those ot Bremus ferricola, i. e. 

 during the latter half of April. Most colonies are probably 

 started in May. Like Bremus pratorum in Europe, Bremus bi- 

 maculatus completes its life-cycle very early. The workers 

 begin to appear in considerable numbers toward the end of May. 

 while most of the young queens and males are produced in June 

 and July. The nests break up in August. 



