480 SEVENTH REPORT OF THE FOREST, FISH AND GAME COMMISSION. 



INSECTS AFFECTING THE TRUNK. The trunk of the pine forms a congenial 

 home for a great many species, some of which attack it while the tree is still vigorous, 

 while others prefer a diseased, dead or even decaying condition. Each species has 

 well-defined food habits, and as a rule it thrives only under certain conditions. 

 Beginning at the base of a living trunk, we will work up and then study the species 

 following the primary invaders. 



Bark Borers. This group includes a number of species which operate largely 

 in diseased or nearly dead tissues. .Some forms attack healthy trees and most of 

 them can complete their transformations in dead tissues. 



TURPENTINE BARK BEETLE. 



Dcndroctoinis terebrans Oliv. 



This insect is exceedingly common throughout New York State, and may 



be found working in small numbers at the base of pine trees in almost every 



locality. The most characteristic signs of this beetle's 

 presence are the masses of pitch occurring at the base 

 of larger trees. These e.Kudations are very irregular 

 and ma\ sometimes be nearly concealed by pine needles 

 and other debris on the ground. This insect makes 

 a gallery about -^,6 to Y^ of an inch in diameter, and 

 by preference attacks living tissues, thus causing a 

 flow of pitch from the wounded parts. 



Thir beetle has been met with by the writer in hard 

 pine on Long Island, on both hard and white pine in 

 the vicinity of Albany, and on white pine in various 

 places in the State. In no instance has it caused very 



serious injury, although its pitch masses were sometimes 



quite abundant. 



Description. The adult is a rather stout brownish beetle \ 



from about ■'/l'^ to V^^ of an inch long. The jaws are black, 



the eyes are finely granulated and the head and thorax 



thickly and somewhat coarsely punctured. The wings or 



elytra are striated and somewhat coarsely punctured. The 



general form of the beetle and certain structural details are 



shown in the figure. 



The pupa is white, quite stout and about '4 of an inch 



jong. The lateral edges of the abdominal segments are each provided with a rather 



FIG. I. DENDROCTONUS TERE- 

 BRA NS. 



OKK.INAI.. 



FIG. 2. AN.4L PLATE OF 

 LARVA OF DENDROC- 

 TONUS TEREBRANS. 



ORIGINAL. 



