1921] Vespa arctica, a parasite of Vespa diabolica 139 



colony taken in Ireland. They show that the two species are very 

 closely related taxonomically, and infer that "the old austriaca 

 queen was the foundress of the nest and that both the rufa and 

 austriaca are her offspring." The evidence with which they en- 

 deavor to support this inference seems to us to be very inconclusive. 

 It is indeed surprising that such accomplished entomologists should 

 have failed to take account of the habits of other parasitic Aculeata, 

 such as Fsothyrus and the workerless ants^ which are all so much 

 better known than the wasps they werestudying. 



The occurrence of austriaca in the vicinity of New York City 

 and in British America and Alaska, at once raises the question 

 as to its American host, since rufa is not known to occur on this 

 side of the Atlantic. Bequaert surmises that coiisobrina may be 

 the American host, and maintains that this wasp, "although very 

 different in coloration, is very prol)ably the American rase or sub- 

 species of Vespa rufa L." If this proves to be the case, we should 

 have the short-cheeked, Ijlaek and yellow austriaca living with the 

 short-cheeked, blach and white consohrina, just as our long-cheeked, 

 black and white arctica lives with the long-cheeked, black and 

 yellow diabolica. 



The dates of flight of male and female austriaca and rufa, care- 

 fully recorded l)y British entomologists ( Carpenter and Pack-Beres- 

 ford and Evans (1903)), indicate that the aAistriaca queens issue 

 from hibernation later in the spring than the nest-founding rufa 

 queens. The same is i^robably also true of arctica as compared 

 with diabolica. Hence the parasitic queens, when they first appear 

 in the spring, find the host nests already well-established and con- 

 taining a worker personnel ready to nurse the parasitic brood. The 

 parasitic Psitliyri show the same tendency to enter the Bombus 

 colonies only after their first batch of workers has emerged ( Sladen, 

 1912), and the parasitic ants take a similar advantage of their 

 host species. 



The presence of both host and parasitic queens in the arctica- 

 diabolica nest examined by the senior author at Colebrook, raises 

 the question as to the probable eventual fate of the host queen in 

 infested nests. In the various cases of the mixed colonies among 

 ants the host queen is soon eliminated, and, according to Sladen 

 (1912), the same rule applies to the Bombus queens of colonies 



