192 



TttE CANADIAN ENTOMOLOGlSt. 



24 



25 



26 



Black, elytra sometimes (in var. iuridipennis, Hald.) icotaceous or 



with the tip alone dark. .3 2-. 5 2 in mutabilis, Newm. 



Prothorax much, often suddenly, narrowed anteriorly, with or without 



distinct constrictions 24. 



Basal prothoracic constriction very deep, sides strongly rounded. . 26. 



Basal prothoracic constriction feeble or absent 25. 



Prothorax densely punctured, with median smooth line. Neck very 



close to eyes. Black, without markings. .36-.40 in. .pubera, Say. 



Prothorax sparsely punctured, head longer behind the eyes. Usually 



black, elytra with or without a narrow discal yellow vitta. Varies 



to entirely testaceous. .40-. 52 in vittata, Oliv. 



Black ; legs more or less yellow ; prothorax (in var. ruficoilis, 

 Say) sometimes red, nearly smooth, except at base. Antennae 

 with tendency to become reddish at tips of joints. .28-. 3 2 



in sphcericollis, Say. 



Black, legs almost entirely yellow in most specimens, prothorax 

 occasionally red, finely and sparsely punctured, except at base, 

 where it becomes more pronounced. Antennae with the tips of the 

 joints more evidently reddish, elytra with side margin and long 



discal vitta yellow. .24-. 40 in vibex, Newm. 



Probably the only serious difficulty to confront beginners in the use 

 of the above table will arise in making the choice between the first two 

 divisions; /. e., 2 and 23. Should doubt arise here the assumption may 

 be made that it belongs in the latter, when reference to other thoracic 

 characters or to those of colour will soon show if the student is on the 

 wrong track. The measurements here, as elsewhere, are in the main 

 those of Mr. Leng^ though I have frequently extended them, as shown 



by specimens in my own collections. 



With regard to food habits very little can be 

 said, so iQVf of the Lepturce having been bred ; 

 while the perfect insects are commonly found on 

 flowers, these give little or no clue to the feeding 

 habits of the larvfe. Mr. Harrington has taken Z. 

 subhamata (fig. 29) on oak and also in a beech log, 

 while the pupa of Z. canadensis has been found in a 

 hemlock stump. Z. nitens bores, as a larva, in 

 black oak, Z. vagans in the yellow birch and 

 pignut hickory, Z. proxima has been reared from 

 maple. 



Fig. 29. 



