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 aiders, 
and contained 6 queens, 10 workers, 9 males and a considerable 
number of cells with partially developed larvse. 
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 (clet. Mr. C. W. Johnson). 
This nest also contained several thief ants ( Solenopsis 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 oi Bremus terricola, 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. 
