154 : PLANT LICE. 
The sub-family includes two genera frequently considered 
as types of distinct families. 
In the genus Chermes the feelers are five-jointed, in Phyl- 
loxera three-jointed. The species of the genus Chermes are 
almost without exception confined to coniferous trees. Their 
body is usually covered with a white flocculent matter. 
Chermes pinicorticis Fitch. (The Pine Louse). 
This insect has been repeatedly observed on the ornamental 
and shade pines near our cities, and especially on the Scotch pine, 
and is responsible for much of the “sun scald” or “blight” stated 
Fic. 141—Chermes pinicorticis Fitch: apterous female, upper and underside, en- 
larged 50 diameters; winged form, upper and underside, enlarged 25 diame- 
ters; young larve, upper and underside, enlarged 50 diameters; antennz and 
legs of young larve, enlarged 250 diameters. After Osborn: 
to destroy these trees. The excellent illustration, Fig. 141, first 
published by Prof. Osborn, who studied this insect at Ames, Iowa, 
gives a good idea of its different stages. The larve, (lower right 
hand corner), when first hatched are oval in shape, flattened, yel- 
lowish, or light brown. ‘The antenne are three-jointed; the 
first joint is short and thick; the second is slightly longer, and 
not so thick; the third is three times as long as the first, and 
half as thick, set with a few stiff hairs at the apex, one being 
two-thirds the length of the joint; also a few lateral hairs. Near 
the end of this joint are a few transverse marks or ridges, ex- 
tending part way round. 
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