INSECTS AFFECTING PARK AND WOODLAND TRICES 



259 



Gall insects 



BiiUetlike, hollow, green galls of a leathery texture, may ocriir on hickory siioots in |une, 

 turning black the latter part of the month or early in Julv, and somewhat resi;inlile 

 the black knot of plum . . Hickory gall aphid, Phylloxera c a r y a e c a u 1 i s, ]). 33 i 



Rustic borer 



Xv/otrcc/iiis co/oiiiis Fabr. 



Broad, irregular, shallow galleries in the inner bark and outer sapwood of oak, 

 hickory and several other trees, may be the work of this species. 



Our attention was called in 1903, to a magnificent hickory tree some 

 15 inches in diameter, which was badly infested by this insect, so much so 

 that over 600 beetles were bred from two sections of 

 the trunk, most of them appearing in May. The tree 

 stood by itself, and as it had evidently been recently 

 infested by large numbers of the insects, we are inclined 

 to the belief that they attacked it while living and pos- 

 sibly while in perfect health; certainly their galleries 

 were so numerous that the trunk was entirely girdled, 

 and as the tree was living the preceding year, no other ^, 

 conclusion appears possible. 



Description. The larval galleries of this insect are 

 very irregular, shallow [pi. Ty'i, fig. i], about }^ to yi 

 inch in diameter, and in our specimen, are so numerous Fig. 44 ru 



.... ., , r 11 1 f larged (..riginul) 



that It IS impossible to toliow the course or any one 



larva. The pupae appear to lie from y^ to i inch below the surface of the 

 wood, the galleries penetrating no deeper. The exit holes are slightly oval 

 and a little less than '/j. inch in diameter. 



The adult beetles are blackish, variegated with yellowish or slate white 

 markings, and range in length from a little less to a little over }4 inch. 

 The species may be recognized, according to Mr Wickham, by the unspotted 

 prothora.x, sometimes fasciated with pubescence, and by the absence of an 

 apical and basal pubescent band, the elytral bands being about as broad as 

 other intervals. Mr Leng states that the markings are very variable, but 

 the yellow waved line running from the suture and forming the included 

 mark, seems to be constant and peculiar to the species. 



