110 ILLINOIS BIOLOGICAL MONOGRAPHS [428 



9(8) Suranal process with distal chitinized portion, as long as wide, cylinder-like; suranal 

 process proximad of the distal chitinized portion with two or more whorls of setae; 



distal margin of the distal chitinized portion minutely but distinctly serrate 



Hartigia Schiodte. 

 10(1) PapQliform subanal appendages on the ultimate abdominal segment wanting. 



Syntexis Rohwer. 



Should Cephus and Hartigia (Middleton, 1917) and Tracheitis (Gahan, 

 1920) prove to possess five-segmented antennae, as reported, contrary to 

 the observations of the present writer, the genus Janus can be separated 

 from them by the chitinized dentiform tubercles and Trachelus by the 

 glabrous eighth and ninth abdominal terga. 



Jantjs Stephens 

 Antennae distinctly with five segments; segments 1 and 2 short, 

 ring-like, segment 3 longer, but half as wide as segment 1, segment 4 

 cylindrical, longer than wide, segment 5 elongate-conical, twice as long as 

 wide, subequal in length to or shorter than segment 4; suranal process 

 short, strongly chitinized, nearly as long as wide at proximal end, denti- 

 form tubercles with circular rows of stiff setae on the proximal half, distal 

 half small, depressed, narrowly oblong in cross-section; subanal appendages 

 peg-like, with a minute seta at the distal end, apparently segmented, 

 without setae near the proximal end; lateral area of suranal lobe with 

 2-3 setae; mandible with four dentes. 



SPECIES OF JANUS 



Subanal appendages distinctly two-segmented, segment 1 ring-like, much larger in diameter 

 than segment 2; antennae with segment 5 about one-half as long as segment 4; bores in 

 Salix and Populus abbreviaius Say. 



Subanal appendages indistinctly two-segmented, segments subequal in diameter; antennae 

 with segment 5 subequal in length to or only slightly shorter than segment 4; bores in 

 Ribes species (currant); C integer Norton. 



Adirus Konow 



Antennae distinctly with four segments; segment 4 long, peg-like, 

 bluntly pointed, nearly three times as long as wide, twice as long as 

 segment 3; suranal process large, distal fourth strongly chitinized, sud- 

 denly constricted, circular in cross-section, with chitinized dentiform 

 tubercles; subanal appendages peg-like, fleshy, apparently unsegmented, 

 with setae near the proximal end, these setae separated from the remainder 

 of the setae on the sternum; lateral area of suranal lobe with 20-28 setae. 



Adirus trimaculatus Say. — Middleton has described the larvae in 

 detail. They bore in the stems of blackberry and rose. Thru the kindness 

 of Dr. E. P. Felt, one mature and two young damaged specimens from 



