77 



Host tree. Shore Pine. 



Distribution. Coast of Alaska and probably southward along the coast 

 to California. 



The Genus Hylastes Erichson. 

 Wieg. Archiv., 2: 47, 1836. 



The names Hylastes Er., Tomicus Latr., 1802, and Myelophilus Eichh. 

 (Blastophagus Eichh) have been applied in different ways. The type of 

 the genus Hylastes Erichson, 1836, is Bostrichus ater Paykull; the type of Tomicus 

 Latreille, 1802, is H. piniperda Fabr.; the type of Myelophilus Eichh., 1878, 

 is D. piniperda Linn. It is evident that Tomicus Latreille, 1802, should 

 be used for the allies of piniperda Fab., and either that Hylastes Er. or Myeloph- 

 ilus Eichh. should be submerged. 



Several prominent European writers, including Bedel, Tredl and Hagedorn, 

 have considered piniperda Fab. distinct from piniperda Linn, and the same 

 as ater Paykull. If this were accepted Hylastes Er. should give place to Tomicus 

 Lat., 1802. Other authors, notably Hopkins, 1915, regard piniperda Fabr. 

 and piniperda Linn, as the same, and consider ater Paykull a good species. 

 According to this interpretation Tomicus would replace Myelophilus Eichh. 

 and Hylastes Er. would stand, with ater Paykull as type. 



In my catalogue, 1909, the former interpretation was accepted, and it is 

 probably correct; in the present paper, however, Hylastes Er. is used, solely 

 to avoid confusion, since it is not possible to be certain of the matter, and 

 Hylastes has been used almost invariably by recent authors. 



Key to the Species. 



A The beak with a distinct median carina. 



B Larger and stouter species, length, more than 4 mm.; the pubescence 



very minute, more distinct in the macer group. 



C The strial punctures very small, at the bottom of very narrow 

 deep striae which are separated by very coarsely rugose and 

 strongly convex interspaces; the tibial teeth few and extremely 

 coarse; the sutural strise hardly wider than the others (PL 17, 

 fig. 6). Eastern and Southern United States. 



salebrosus Eichh. 



CC The strial punctures coarse or small between moderately convex 

 interspaces, or small between flattened wider interspaces; the 

 tibial teeth only moderately coarse (PI. 17, fig. 8). 

 D The interspaces distinctly convex on the disc and declivity; 

 the pronotum usually at its widest part but little narrower 

 than the elytra. 

 E The head and pronotum roughly, rather coarsely punctured, 



the body variably shining. 

 F The elytral interspaces densely coarsely rugose. 



G The elytral strise strongly impressed; the strial 

 punctures coarse, as wide as the narrow interspaces 

 on the disc, the pronotal punctures very coarse and 

 only moderately close. Southern United States. 



scaber Sw. 



GG The elytral strise moderately impressed on disc and 

 declivity, only very faintly on the sides; the strial 

 punctures rather small, narrower than the inter- 

 spaces on the disc; the pronotal punctures of medium 

 size and very closely placed. Colorado, asper Sw. 



