A WASP THAT PROVISIONS ITS NEST WITH QUEEN ANTSj 377 



burrow. A slender twig or grass culm carefully introduced into 

 the opening of the nest as a probe was invariably stopped a 

 few inches below the surface by an earthen plug or partition 

 which has to be removed by the wasp whenever she enters the 

 deeper portions of the nest. 



The prey of A. frigidus consists exclusively of winged queen 

 ants belonging to the genus Formica. Specimens wrested from 

 the wasps while being brought in and also dug from the nests, 

 belonged to the following four forms : 



Formica fusca L. var. subsericea Say. 



F. fusca L. (typical). 



F. (Neoformica) pallidefulva Latr. subsp. nitidiventris Emery. 



F. (Proformica) neogagates Emery. 

 Most of the specimens belonged to subsericea, very few to neo- 

 gagates, while the true fusca was more abundantly represented 

 than nitidiventris. The nature of the prey, however, depends 

 on the situation of the Aphilanthops colony. Thus the prey 

 in the Administration Road colony, which was situated very 

 near the northern side of Great Blue Hill, consisted almost 

 exclusively of the typical fusca, which is the only form of the 

 species on this more boreal slope, whereas the more xerothermic 

 subsericea and nitidiventris were the only forms found in the 

 colony situated on the southern slope. As these two colonies 

 were less than a mile apart, it is clear that the wasps do not 

 range very far in search of their prey. The same wasp may 

 collect queens of two or even three of the four Formicas enum- 

 erated above. The pronounced preference for the queens of 

 fusca and its variety subsericea is shown also in other portions 

 of the geographical range of A. frigidus. I have already stated 

 that the specimens of this wasp taken by Hebard in northern 

 Michigan had been preying on fusca. Recently ( while I was 

 visiting my friend Dr. C. Gordon Hewitt at Ottawa, Ontario, 

 the noted melittologist, Air. Sladen, showed me a specimen of 

 the wasp taken August 12, 1Q13, with a winged queen of the 

 typical fusca. He pointed out to me the site of the colony 

 where he had seen this and other specimens of the wasps carry- 

 ing in their prey, in the midst of a cultivated plot on the Central 

 Experimental Farm, but all traces of the nests had disappeared 

 at the time of my visit (September 2). During August, Mr. 

 C. W. Johnson brought me a specimen of frigidus mounted on 



