MAPLE BORERS. 379 



August and September, so as to drive off the beetles and to destroy the 

 freshly-hatched grubs, but since discovering how easily the grubs and 

 castings of the freshly-hatched worms can be detected a few days or 

 weeks after the eggs have been laid, it seems obvious that the easiest 

 and surest preventive is to cut out the grubs when lying in their 

 autumn and winter quarters just under the surface of the bark. It is 

 almost impossible to destroy the fully- grown worms in their "mines" 

 or burrows, since the latter extend up the tree either directly under the 

 bark or are sunken in the wood. On one tree nearly destroyed by this 

 borer, out of about fourteen mines twelve extended upward. Hence it 

 is useless to try to find the hole and inject oil into it. There now seems 

 no reason why valuable shade maple trees should not be saved by a 

 few hours' close observation and removal of the young grubs, say in 

 September or October. 



The beetle is black, with a yellow head, with the antennae and the eyes reddish- 

 black ; the thorax is black, with two transverse yellow spots on each side ; the wing- 

 covers for about two-thirds of their length are black, the remaining third is yellow, 

 and they are ornamented with bands and spots arranged in the following manner : a 

 yellow spot on each shoulder, a broad, yellow, curved band or arch, of which the yel- 

 low scutel forms the keystone on the base of the wing-covers; behind this a zigzag 

 yellow band forming the letter W, across the middle another yellow baud arching 

 backwards, and on the yellow tip a black curved band and spot ; legs yellow, while 

 the under side of the body is reddish- yellow, variegated with brown. Nearly an inch 

 in length. (Harris.) 



2. The horn-tail borer. 



Tremex columba (Linnaeus). 



Order Hymenoptera ; family Urocerid^. 



Boring in the trunk and making large round holes, a large white grub with a promi- 

 nent spine on the end of the body, and transforming in the late summer into a large 

 clear- winged saw-fly, with a long large " saw" on the tail of the female. 



This interesting insect bores indifferently in various forest and shade 

 trees, attacking the elm, oak, sycamore, and perhaps more commonly the 

 maple. The holes of this borer may be recognized by their large num- 

 bers within a given space, and by their regular, evenly-cut shape, being 

 about the diameter of a lead-pencil. We remember seeing some years 

 ago a tree at Saratoga Springs, in the trunk of which, where the bark 

 had been removed, were a dozen or more of the round even holes made 

 by these insects, which seem to work some ^vhat in concert. Isolated 

 shade trees along roads and in streets are favorite habitats. Harris 

 says that an old elm tree in his vicinity used to be a favorite place of 

 resort for this saw-fly, numbers of them collecting about it during the 

 months of July, August, and the early part of September. " Six or 

 more females might frequently be seen at once upon it, employed in 

 boring into the trunk and laying their eggs, while swarms of the males 



