This insect is also known as the Oak Carpenter-\\k)nii, 
but in Colorado it is known almost exclusively as a cotton- 
wood borer. The larva, when fully grown, is nearly three 
inches in length, with a shining black head, and it cuts large 
holes in the trunks of the trees. Its work is most often 
noticed where a limb has been cut off or the trunk injured 
in some other way. The castings of the borers are pushed 
out on the surface and the tree bleeds as a result of the 
wounds made to the surface. The sap runs down on the 
trunk and sours, making a breeding place for maggots of 
certain dies. The moths have been taken at night at Fort 
Collins between June 14th and July 21. The females are 
larger than the males and both are well represented in the 
accompanying dgure at about life size. The general color 
is gray, but the male has a large yellow spot covering the 
central portion of the hind wing on either side. 
Remedies — It is hard to suggest a good remedy for this 
insect. Tacking a little wire gauze over the burrow before 
the middle of June would prevent the escape of the moth. 
Probably a wooden plug driven into the hole would serve 
the same purpose. With a stout wire one could kill many 
of the larvae or pupm in their burrows. Avoid scarring the 
trees as much as possible as the borers usually enter at such 
places. 
The cottonwood is also attacked by Plant Lice, Pall 
Webworm and Putnam Scale, which have already been men- 
tioned with their remedies. It is also attacked by a white 
scale { Chionaspis ortholobis), much resembling the scale 
figureri on a following page on pine and spruce leaves. 
Remedies the same as for the other scales. 
THZ ELM LEAF-CLUSTER GALL. {Srh i -on ru nt ninrrlcnnn, 
Riley.) 
d'he author's observations up'on elms on the College 
grounds the present spring show that this louse appears on 
the trees before the leaf-buds begin to open, and that it at- 
tacks the base of a bud, soon becomes covered with a white 
flocculent secretion (see Fig. 32, e,) and that the bud, as it 
opens, curves downward so tliat the leaves hide the louse. 
The attack stimulates the opening of the bud and the 
growth of the leaves so that they are usually in advance of 
the other buds of the tree. By the middle of June, the in- 
fested leaves have formed a loose cluster, often as large as 
a man’s hst or larger, within which is a disgusting mass of 
