SCALE-INSECTS, BARK-LICE, MEALY-BUGS. 219 
of a cottony substance in which the eggs are deposited, and where 
they are protected. 
Pulvinaria innumerabilis Rathv. (The Cottony Scale). 
This is an exceedingly common and destructive species, 
which sometimes occurs in such vast numbers that the under side 
of the twigs of box elders and maples are snow-white, beirig cov- 
ered in spring with the white cottony substance enclosing the 
eggs. Wherever insects occur in such numbers the leaves have a 
wilted and sickly look, while the pavement below becomes coated 
Fic. 180—Palvinaria innumerabilis Rathv.: a,leaf covered with young scales; b, 
male scale; c, adult male. After Div. of Entomology, Dep. of Agriculture. 
with a black and sticky substance, the honey-dew, upon which 
a peculiar fungus grows. Later in the season the leaves, espe- 
cially on the under side, are coated with a larve, and they are 
sometimes so numerous that the writer has counted as many as 
5,017 upon a single leaf. Usually, however, they do not coat 
the whole underside, but are chiefly confined to the vicinity of 
the larger ribs. The illustration, Figs. 179 and 180, gives a good 
of this insect in its various stages. 
“The insect usually attracts attention late in May or early 
in June. when the gravid female excretes from beneath the scale 
a mass of pure white, waxy or cottony material in which the 
eggs are deposited. 
