170 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [BuU. 



wanting, sometimes represented by a small spur; head 

 with a white spot behind the eyes 2 



Cornus at apex of abdomen of female either shouldered 

 or not, but never constricted at base and spear-shaped; 

 front wings with free part of Cuz distinct; head without 

 a white spot behind the eyes; posterior tibiae with two 



apical spurs , Sirex p. 170 



2. Posterior tibiae with two apical spurs; ovipositor about as 

 long as the abdomen, and always much shorter than the 

 body Urocerus p. 171 



Posterior tibiae with only a single apical spur; ovipositor al- 

 ways much longer than the abdomen, and sometimes 

 longer than the body Xeris p. 171 



Sirex Linnaeus 



Key to Species. 



1. Abdomen blue-black 2 



Abdomen more or less red 3 



2. Legs blue-black; abdomen short, cornus short and shouldered, 



ovipositor projecting but little beyond its tip; body steel- 

 blue, with first pair of legs below knees dark ferruginous; 



wings violaceous. Length 35 mm. (female) edwardsii 



Legs rufous; cornus elongate, pointed, not shouldered at 

 base, diminishing gradually in size; body black, with legs 

 beyond trochanters, and base of ovipositor, yellow or 

 rufous; wings hyaline or nearly so, sometimes with a spot 

 below the stigma and apex of the wings infuscated. 

 Length 16-30 mm. (female) cyaneus 



3. Wings violaceous; body blue-black, with legs beyond knees, 



sometimes the whole of the legs, abdomen beyond first or 

 second segment, cornus, and ovipositor, red; cornus some- 

 what convex at sides but not distinctly shouldered. 



Length 28 mm. (female) nigricomus 



Wings hyaline or yellowish, apical margins sometimes some- 

 what infuscated : 4 



4. Legs entirely blue-black 5 



Legs with posterior femora rufous; body bluish, with poste- 

 rior legs more or less, and abdomen beyond second or 

 third segment, rufous; wings hyaline or nearly so. Length 

 15-30 mm. (male) cyaneus 



5. Abdomen entirely rufous beyond basal plates or first seg- 



ment; antennae and posterior tarsi sometimes marked with 



rufous. Length 20 mm nigricomus 



Abdomen blue-black, with only the fifth or sixth segment 

 rufous (male) edwardsii 



