INSECTS AFFECTING FOREST TREES. 



491 



'foiiiiciis hahaincits Lee, another species of Pityogcncs, Hypopldocns species, and a 

 L'h.dcid ; the latter two were not determined. This insect was also met with in Sep- 

 tember of the same year at Hath-on-the-Hudson, where it was boring dead limbs of 

 white pine in which were to be found larvae, pupae and adults. This latter tree had 

 also been attacked by Toiiiicns calligraplius Germ. The borings of this insect are 

 •quite irregular. There is a rather large irregular central chamber, with three to four 

 or five primary or egg galleries diverging sometimes at right angles and sometimes 

 obliquely to the wood fibers. In one case noticed, several larval galleries originated 

 from the central chamber, showing that the eggs, in at least one instance, were 

 deposited in little notches in its wall. The primary or egg galleries are from about 

 I to I 'i inches in length, and from them arise the slender, somewhat tortuous 



\ -) 



FIG. 9. WORK OF PITYOPHTHORUS SPECIES IN WHITE PINE. 



ORIGINAL. 



larval galleries, which may attain a length of about 1^2 inches. Pupation occurs at 

 the tip of the mine in a slightly enlarged cell, which is sometimes excavated in the 

 sap wood. 



Pityogcncs Species. 



Another species of this genus, stated to be a new form by Dr. Hopkins, was met 

 \\\\\\ b_\- us at Saranac Inn, in August, 1900. It was operating in a nearly dead 

 young pine and its galleries were quite different from the preceding. Its central 

 chamber is not so large, the notches for the reception of the eggs are placed a little 

 further apart, and the larval galleries do not cut the wood so deeply as a rule. The 

 jjupal cells are e.xcavated to a much greater depth in the sap wood. The work of 

 this species is illustrated in plate 10 figure 4. Apparently the same species was 

 met with in another white pine where it was associated with Toiiiicns caclatus Eich., 

 and also in dying balsam, where it occurred in company with the last named species 

 and with Toiuicus halsaiiiciis Lee. 



