56 
(Fig. 60, a, c) is about a tenth of an inch in length, irregularly- 
oval, with a yellowish point at one end, and but very slightly con- 
vex. It is nearly white when fresh, but becomes gray or sooty 
with exposure. The scale of the male insect (Fig. 60, b, d) is 
Fig. 60. Scurfy Scale, Chionaspis furfur a: 
a, h. female and male scales, natural size; c, 
d, same, enlarged. 
narrow, with sub-parallel sides, and is marked by three longitudinal 
ridges. The species may be readily recognized in winter by the 
fact that under each female scale will be found a small mass of 
minute, purplish eggs. The young appear to the naked eye as 
active, snowy whitish or reddish specks. These insects are often 
so abundant on an infested tree as to give a scurfy appearance to 
the trunk and limbs. 
This scale insect is a general feeder, but is especially common 
on rosaceous plants. It also heavily infests the elm, which seems the 
most susceptible to its injuries of any of our ordinary shade trees. 
The red-twigged dogwood is often incrusted by it, and the moun- 
tain ash, hawthorn, pear, and currant are sometimes attacked. The 
scurfy scale winters in the tgg, and hatches, with us, during the 
latter half of May — earlier or later according to the season and the 
part of the state. In central and southern Illinois eggs are laid 
for a second generation, the date of which, however, has not been 
accurately determined. Altho this can not be classed among the 
more destructive scale insects, it is nevertheless injurious where es- 
pecially abundant, checking the growth and diminishing the vitality 
of the infested tree or shrub in a way to make it less presentable and 
more susceptible to the attacks of other insects and of disease. 
Two insecticide sprays are fairly effective against this insect; 
one a winter spray of lime and sulphur, prepared and administered 
as described in detail under the article concerning the San Jose 
scale, and the other a summer spray of kerosene emulsion, a formula 
