642 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



Vespula Thomson. 

 This compact, well denned genus may be separated into two 

 subgenera on the length of the malar space as follows : 



Key to Subgenera. 

 Malar space very narrow, eyes touching base of mandibles or 



separated from them only by a line Vespula p. 642 



Malar space very broad, eyes remote from base of mandibles 



Dolichovespula p. 642 



Dolichovespula, new subgenus. 

 Type: Vespa maculata Linnaeus. 



Key to Species. 



1. Basal three abdominal segments immaculate; markings white; 



flagellum ferruginous beneath maculata 



Basal three abdominal segments maculate 2 



2. Black and white arctica 



Black and yellow diabolica 



V. (D.) maculata (Linnaeus). Vespa maculata Linnaeus. 

 White-faced Hornet. PI. viii, Fig. 16 (adult) ; PI. ii, Fig. 1 

 (nest). 



The nest is attached to the limb of a tree. 



A very common species, occurring throughout the State. 

 Windsor, New Haven, Wallingford (W. E. B., B. H. W.). 



V. (D.) diabolica De Saussure. Common Yellow-jacket. PI. 

 viii, Fig. 13 (adult) ; PI. iii (nest). 



According to Ashmead this species nests in stumps. 



Another common species which occurs throughout the 

 State. New Haven, Mount Carmel, Branford, Prospect, 

 Sachem's Head, Colebrook (W. E. B., B. H. W., H. L. V., H. 

 W. W.). 



V. (D.) arctica, new name. V. borealis Lewis (Trans. 

 Amer. Ent. Soc, vol. 24, 1897, p. 173), not V. borealis Kirby 

 (Fauna Boreali-americana, 1837, P- 2 ^4)- 



This species has been taken in New Hampshire, and at 

 Amherst, Massachusetts, and will undoubtedly be found in north- 

 ern Connecticut. 



Subgenus Vespula Thomson (s. str.). 

 Type: Vespa austriaca Panzer (Ashmead, 1902). 

 To this subgenus belong the numerous smaller vespine wasps 



