

145 



joint (not all) but slightly bilobed. Illinois species small, few exceed- 

 ing or even reaching one-fourth of an inch in length. 



The larvae are small, short, thick, somewhat cylindrical, fleshy 

 grubs, much wrinkled on the back, and footless, and, so far as known, 

 residing in trees as bark-miners or wood-borers. 



Scolytus 4-spinosus — Say 



(S. cary.e — Riley.) 

 borer.) 



(The hickory bark- 



LFig. 22.] 



This is short, oblong and 

 nearly cylindrical in form. 

 The antennae very short and 

 terminated with a club ; the 

 thorax is quadrate in form 

 and very large, almost equal 

 in size to the part of the body 

 behind it. Length one-fifth 

 of an inch, or little less. Color 

 entirely black, or black with 

 brown wing-cases. 



The female beetle, select- 

 ing the trunk or larger limb 

 of a hickory tree, bores 

 through the bark and forms 

 a vertical chamber next to 

 the wood from half an inch 

 to an inch in length, on each 

 side of which she deposits 

 her eggs, varying in number 

 from twenty to fifty. The 

 larvas when hatched feed on 

 the inner bark, each one 

 forming a track of its own, 

 thus forming the radiating 

 l, shows burrows so common on the 



the burrows of the larvae between the bark and the under side of the bark of 



wood, growing wider as they diverge from the line , . . . 



where the eggs are deposited ; 2, another view of the IllCKOry trees. 



same, showing the hole made by the exit of the beetle ; TJiolirvn i«n soft vpllnwi<?Vi 



3, beetle, both magnified and natural size ; 4, larva, the x xl n e idr v cl lB < l * ul l ' J L . 1 . m * * 



same; 5, pupa magnified. footless gl'llb, milch like the 



larva of some of the curculios, and from which it cannot easilv be dis- 

 tinguished, except by its habits ; it is very small, not exceeding the- 

 fifth of an inch in length when fully grown. 



The eggs are deposited during the months of August and Septem- 

 ber, and the beetle issues about the latter part of June or first of July. 

 It attacks the bitter-nut, shell-bark and pig-nut, hickories, and. 

 probably, the pecan. 



No practical remedy is known, nor is there much probability of 

 any extensive experiments being made until forest timber becomes 

 more valuable than it is now. 



Spec. char. Imago.— Entirely black, or black, with brown elytra. 

 The head is depressed above, and marked with abbreviated longitu- 



e— 10 



