1921] Vespa arctica, a parasite of Vespa diaholica 137 



larvae belonged to diaholica. These large larvse, which were nearly 

 ready to pupate, must have belonged to arctica, and were probably 

 females. That they had been alnindantly fed by the diaholica 

 workers and their development favored beyond that of the remain- 

 ing larvffi was evident from a glance at the two combs. Examina- 

 tion of the two queens, which were of the same size, showed that 

 their wings were mutilated. The apical halves of both wings of 

 the arctica queen on the right side had been bitten off. As both 

 queens were still fresh when found in the nest on the morning of 

 July 8 (the diaholica queen, when stimulated, still moved her tarsi !) 

 we may infer that both were living together in the nest, though 

 probably not on the best of terms, that the arctica queen had prob- 

 ably entered the nest just as the workers were beginning to build 

 the second comb and had oviposited in 11 of its cells, and that the 

 resulting larvae were being actively fed by the diaholica workers, 

 because the parasite's wings were too much mutilated to permit 

 her to leave the nest and forage. 



2. On June 29, the .junior author killed a colony of diaholica 

 which had its nest in the hay-scales of the State Antitoxin Labor- 

 atory on the grounds of the Bussey Institution. It was younger 

 than the preceding, had one comb and only a few cells of a second, 

 and contained only a small number of diaholica workers and an 

 arctica queen. Since the colony was captured during the day, 

 most of the diaholica workers were probably out foraging, and the 

 absence of the diaholica queen may, perhaps, be accounted for on 

 the same supposition. 



3. August 4, the junior author took in the Arnold Arboretum 

 a nest of diaholica containing three recently emerged males of 

 arctica. In the same nest were about a dozen large larvae and two 

 or three pupae, evidently queens, though whether of diaholica or 

 arctica was not determined, as they were unpigmented. In all 

 probability, however, they belonged to arctica. The presence of 

 worker larvae and pup^e indicated that the queens of both species 

 were in the colony at about the same time (that is, if the time for 

 development of diaholica workers is about the same as that required 

 for the arctica males), and that at least one of the queens had 

 .been in the nest very recently was indicated by the numerous eggs, 

 although these might, of course, have been laid by the workers. 



