156 PLANT LICE. 
Remedies and Enemies. ‘The insect has its natural enemies 
in common with most of our other plant-lice; but on account of 
the scattered nature of our pines in the region infested, these 
enemies do not keep it in check. We must, therefore, adopt other 
methods of warfare if we would get rid of it and save our trees. 
The kerosene emulsion is the best thing that we know of for this 
purpose.” 
Some species of the genus Chermes produce very peculiar 
swellings at the ends of the twigs of the spruce, which somewhat 
resemble the cones of the same trees. Such swellings are some- 
times found on trees sold in our markets as Christmas trees. A 
similar one, very common in Europe, is shown in Fig. 142. Our 
species, (C. abieticolens Thos.) looks very much like it. 
Fic. 142—Gall-like swelling produced by Chermes. After Brehm. 
Another species, the Larch Chermes, (C. laricifolie Fitch), 
is shining black, about one-tenth of an inch long, with a dark 
green abdomen, whitish or pale legs, hyaline wings, with pale 
brown veins, and a large, opaque, pale-green stigma. It occurs 
on the leaves of the Ameritan larch or tamarack. 
The genus Phylloxera is only too common in at least one 
species, and few of our cultivated grape-vines are entirely free 
of the root-inhabiting form, while the leaves of some of our wild 
species are covered year after year with numerous galls produced 
by another form of the same species. 
