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



Vespula Thomson. 

 This compact, well defined 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) ; PL ii, Fig. i 

 (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. PL 

 viii, Fig. 13 (adult) ; PL 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. horealis Lewis (Trans. 

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

 (Fauna Boreali-americana, 1837, P- 264). 



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 



