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



Sphecodes Latreille. 



The bees of this genus are parasitic upon species of Halictus. 

 In addition to the head and thorax, the abdomen is in some species 

 black, though usually more or less red in the female. 



Key to Species. 



Females. 



1. Mandibles rufous, base usually largely black 2 



Mandibles yellowish or reddish, with tip darker; flagel, tibiae, 



and tarsi dark; enclosure distinct, coarsely reticulated; 

 labrum entire mandibularis 



2. Mandibles dentate; labrum not notched; fourth joint of 



antennae equals or nearly equals second or third 3 



Mandibles simple; labrum notched confertus 



3. Vertex without a tubercle 4 



Vertex with a distinct tubercle; mesonotum closely and 



coarsely punctate; abdomen finely and sparsely punctate; 

 fourth and fifth segments of abdomen black, remainder 

 red heraclei 



4. Abdomen, or at least first dorsal segment thereof, impunctate 



or nearly so; mesonotum not sulcate; abdomen entirely 



red minor 



Abdomen rather evenly, coarsely, and distinctly punctate, 

 fifth segment of abdomen blackish, remaining part of ab- 

 domen red arvensis 



Males. 



1. Fourth antennal joint about equal in length to second and 



third combined 2 



Fourth antennal joint hardly longer than third; scutel 

 sparsely punctate and shining; abdomen more or less 

 reddish mandibularis 



2. Third antennal joint twice as long as second; flagel notched 



beneath near apex; mandibles red; abdomen black, with 



seventh dorsal segment red, at least at apex confertus 



Third antennal joint not twice as long as second; fourth to 

 thirteenth joints of flagel notched beneath and presenting 

 distinct facets; abdomen entirely black; vertex without 

 a tubercle; mesonotum with distinct punctures; abdomen 

 not shining, closely punctate and closely pubescent . .arvensis 



S. (Drepanium) arvensis Patton. 



This species has been taken at Colebrook, New Haven, 

 Rockville, Sachem's Head, Scotland, Stafford, and West Haven, 

 in May, June, July, and August, either at random or visiting 



