3OO MAURICE COLE TANQUARY. 



might just as well be a hybrid between latipes and inter jectiis 

 as between latipes and daviger. 



LASIUS UMBRATUS VAR. MINUTUS. 



One of the quotations given above shows the lack of evidence 

 that the queens of this species are able to found their colonies 

 independently. The lack of such evidence taken together with 

 the fact that the ant is sporadic in its occurrence, that it produces 

 an immense number of the sexual forms and that the females 

 differ from all the other Lasius females in being very small, 

 no larger than the largest workers, point to temporary paras- 

 sitism as a method of colony formation. 



On August 12 I came across a large mound nest of this species 

 at the edge of a forest reservation near the Arnold Arboretum. 

 The mound was in the shape of a very broad dome, about eighteen 

 inches high and about three feet across at the base. Judging 

 from the size of the nest, the number of individuals and the way 

 the grass was shot up through the mound the colony must have 

 been several years old. With a trowel I took out about a quart 

 of dirt from the side of the mound and brought it to the labor- 

 atory. I found that I had about 150 females, an equal number 

 of males, several hundred workers and many cocoons. As the 

 amount of earth I removed hardly made an impression on the 

 mound the colony must have contained several thousand males 

 and females and a still larger number of workers. Although I 

 collected rather extensively in that region and in a number of 

 other localities around Forest Hills, this is the only colony of 

 minutus that I found during the entire summer. In my ex- 

 periments w r ith this species I used 88 queens in 20 different 

 colonies as follows. 



B. 250. 

 20 workers, 2 winged queens and brood of L. americanus. 



B. 256. 

 8 workers and many pupae of L. americanus, 



B. 2Sc. 

 8 workers and many pupae of L. americanus. 



B. 2 5 d. 



30 workers and many pupae of L. americanus. 

 B. 28/1. 7 workers, no brood of L. daviger. 

 B. 28/2. 24 workers and a few cocoons of L. americanus. 



