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there appears over its body a slight covering of waxy or cot- 
tony material, which serves both for protection and conceal- 
ment. Soon afterward the larva commences to secrete a firm, 
papery, shield-like covering, which in time becomes the scale 
proper. During the completion of this scale, the skin is shed 
once by the male and twice by the female. Both sexes lose 
their legs and antennee in shedding the skin, thus becoming 
mere immoveable sacks capable only of feeding and secreting the 
scale. The mouth of the louse is provided with a long, slender 
and thread-like sucking-tube which is thrust into the tissue of 
the plant, and serves as a sort of hose through which to suck 
the sap. ‘To secrete the scale, the louse is provided with many 
spinnerets at the rear end of the body. The arrangement of 
this spinning apparatus is used to classify the numerous 
species of bark- lice. 
In due time the male molts for the second time and changes 
to the pupal stage, during which time wings, antennee, legs and 
other appendages are formed inside the pupal skin. Before 
long the male emerges as a delicate, two-winged insect with 
one or two long and tail-like appendages. As the life of the 
male is very short no food is required, and consequently the 
mouth is rudimentary and a second pair of eyes takes its place. 
The female bark-louse always remains under thescale. After 
the union of the two sexes the male soon dies and the female 
commences to lay eggs, retiring into one end of the scale and 
gradually shrinking during the process to a mere shriveled 
skin. 
The time when the eggs are laid varies with the species, 
mapy laying them during the autumn, but some passing the 
winter in a partly-grown condition, deposit the eggs in the 
spring. The forms of the scales vary considerably, most of 
the species having a characteristic appearance which can be 
distinguished by the naked eye. 
Remedies. 
As most of these insects, when old, are provided with water- 
proof coverings and can not be easily reached by spraying, it 
is advisable to spray when the young and still unprotected 
larvee move about in search of a suitable place to settle, or just 
after they have settled down and commenced to secrete the 
‘ 
