SCOLYTUS. , 95 



II, Elytra brown or red -brown. 



Black ; elytra brown or red-brown ; antennae and legs 

 reddisli-yellow-brown. Forehead of male with short pu- 

 bescence, that of female not ridged ; clypeus less deeply 

 emarginate than in S. Batzehurgi, thorax broader, elytra 

 less parallel-sided, abdomen with a minute tooth at anterior 

 margin of third and fourth segments in both sexes and 

 punctured (although finely) more deeply and closely, espe- 

 cially on apical segment. L. 2^ 1. Common ; in Elm. 



S. destructor, 01. 



b. Abdominal ventral segments simple. 



Black, shiny ; anterior and posterior margins of thorax 

 and the elytra brown ; antennae and legs red-brown. 

 Thorax almost as long as broad, narrowed in front ; elytra 

 with fine punctured striae, interstices with a still finer row 

 of punctures. L. If — 2 1. Not common. S. pruni, Eatz. 



H, Thorax rather closely and strongly punctured. 



(I. Abdominal ventral segments of male simple. 



I, Interstices on elytra rather more finely punctured 

 than the striae ; elytra unicolorous. 



Black ; shiny ; antennae and legs rust-red ; femora and 

 elytra pitch-brown, latter with very close rows of punc- 

 tures, with short, erect yellow bristles at sides and toward 

 apex ; under-side with close, gray pubescence. Tliorax 

 almost broader than long, rather strongly and closely punc- 

 tured, more feebly in middle, coarsely and almost in 

 wrinkles at sides ; suture depressed close behind scutellum 

 only, without trace of sutural furrow. L. 1\\. Not uncom- 

 mon. S. intricatus, Ratz. 



II. Punctures on interstices of elytra as large and 

 deep as those in striae ; apex of elytra reddish- 

 brown. 



Black, shiny ; apex of elytra, antennae and legs reddish- 

 brown. Thorax extremely closely covered with deep, 

 oblong punctures, confluent into wrinkles in front and at 

 sides. L. | — 1 1. Eather common. S. rugulosus, Eatz. 



h. Second ventral segment of abdomen in male with a 

 large, horizontal, prominent tooth. 



Black ; elytra brown, apex (rarely entirely) red-brown, 

 antennae yellow-brown ; legs red. Elytra with very 



