352 NEW YORK STATE MUSEUM 



white pines at Round Lake N. Y. in the summer of 1901. The destructive 

 work of this little borer was further evidenced by a complaint from Jeremiah 

 Day, Catskill N. Y., December 1901, to the effect that 50 young white 

 pines about 25 or 30 years old had been killed during the preceding summer 

 and the examples of the injured bark proved that this species was the dep- 

 redator. It is very evident that this little borer can seriously injure if it 

 does not kill a tree outright. It was met with on pine and tamarack at 

 Big Moose N. Y., July 8, 1903, evidently attracted to the recently burned 

 trees. 



Description. The beetle is slightly larger than Tomicus caco- 

 graphu s Lee, being about s/ 32 inch long and usually a little stouter. It 



varies in color, like the preceding, from a light to a 

 l very dark brown. One of the most prominent char- 

 ) acteristics of this species is the presence of but four 

 I teeth on each side of the conspicuous posterior exca- 

 vation or declivity of the elytra. They are arranged 

 '-11^^^ a s follows : the dorsal one near the median line is 



Fig. 70 Declivity of To m i c 11 s . . • • 1 r 1 1 



pin i (author's illustration) minute and sometimes wanting in the female; the 

 second and third are larger, specially the latter, and touching at the base ; 

 the fourth is much smaller and independent. The prothorax is rather 

 coarsely granulated and the elytra or wing covers are ornamented with 

 longitudinal rows of rather small punctures. The antennal structure is 

 shown on plate 66, figure 7 and that of the tibia in figure j\a. 



Life history and habits. The typical form of the burrows of this insect 

 is well shown in plate 57, figure 3, which represents the central or entrance 

 chamber and an adult gallery. The latter is about inch in diameter, and 

 leading therefrom are somewhat tortuous expanding larval mines, rarely 

 more than x / 2 inch in length. The specimen of bark photographed shows 

 also tlie work of what is probably a young Monohammus larva. It will be 

 seen by an examination of this figure that, in this case at least, two females 

 continued their work from the central chamber, one going up and the 

 other down approximately parallel with the bark fibers. A more advanced 



