PSYCHE 



VOL. XXVIII OCTOBER. DECEMBER. 1921 Nos. 5-6 



VESPA ARCTICA KOHWEE, A PAEASITE OF VESPA 

 DIABOLICA DE SAUSSURE.i 



By W. M. Wheeler and L. H. Taylor. 



The summer of 1921, at least in New England, was a "wasp 

 summer,'' probably on account of the protracted, hot, dry weather 

 during June and July. Certain species of Vespa, especially the 

 common yellow- jacket, V. diabolica, were unusually abundant. 

 Probably for this reason we were able to make the following obser- 

 vations on a rare wasp, Y- arctica, which, as shown by Fletcher 

 in a paper read before the Entomological Society of America 

 (1908), is a parasite in the nest of diabolica. Unfortunately, 

 Fletcher died before he could publish his paper, and the very 

 brief notice of it in the proceedings of the Society is all that has 

 appeared. 



During the summer of 1921 the senior author spent his vacation 

 at Colebrook, in the Litchfield Hills of Connecticut; the junior 

 author at Forest Hills, near Boston. In both places a number of 

 diabolica nests were examined, and in three of them arctica was 

 taken. The latter species- is black and white, and in size and 

 marldngs may be very readily mistaken for V. consobrina De 

 Saussure, but closer examination shows that it has long cheeks and 

 long hairs on the tibiffi. It lacks, moreover, the worker caste, and 

 therefore differs from all known species of Vespa, except austriaca 

 Panzer, which will be considered more fully in the sequel. This 

 absence of the worker caste at once suggests that arctica is a social 

 parasite like the species of Psithyrus in the nests of bumble-bees 

 and certain ants {Anergates, Epoecus, Epiplieidole, Sympheidole, 

 Anergatides, etc.) in the nests of Tetramorium, Monomorium and 



> Contributions from tlie Entomological Laboratory of the Bussey Institu- 

 tion, Harvard University. No. 195. 



^ This species was originally described by Lewis (Trans. Amer. Ent. Soc 

 24, 1897, p. 173) as Vespa borealis, but Rohwer (in Viereck, Hymenoptera, or 

 Wasp-like Insects of Connecticut, 1916, changed the name to arctica, as 

 Kirby had previously described a V. borealis (Fauna Boreali-Americana, 

 1837, p. 264). 



