THE COTTONY MAPLE SCALE 
9 
the male larvae looses its rostrum and its anal cleft, although the wing pads have not 
yet developed; the antennae are stout and laid backward without perceptible joints, 
and that end of the body is furnished with two long conical tuberculae. After the 
third skin is cast, an apparent propupal stage is found which bears wing pads reaching 
to the abdomen; the claw of the tibia is lost, and between the posterior tubercles has 
appeared a stout, rudimentary style.”—Howard. “A long pair of wax filaments is 
secreted from the anal extremity and these continue to grow during the life of the 
insect. It is the protrusion of these filaments from beneath the waxy scale which 
indicates the approaching exclusion of the male.”—Riley. 
The changes in the female scales are less conspicuous but never¬ 
theless characteristic. After the first molt they broaden posteriorly 
and have a slight dorsal carina. When the males appear, they have 
undergone a second molt and changed from pale yellow to light green 
and are marked with a brown dorsal stripe the whole length of the body. 
The males appear during the latter part of August or first of Sep¬ 
tember, copulate with the females in a few days and die. 
The summer injuries are most conspicuous on the leaves. Dr. 
Forbes states that in 1884 many trees at Bloomington, Ill., had lost a 
considerable portion of their leaves by August 16, and the others were 
blackened and dwarfed, giving the branches a bare and unthrifty look. 
In early October the gravid females desert the leaves and find 
places for hibernation on the branches and twigs. Immense numbers 
drop to the ground with the falling leaves which results in a great loss 
of life from the inability of many to find their way back. The position 
sought is the under sides of the twigs and smail branches, the lower 
branches of the tree being usually most densely populated. Many 
locate around the crotches and on the upper sides of the twigs. The 
scales are still quite flat and about one fourth grown, varying from one 
and one half to two and one half millimeters in length. The posi¬ 
tion assumed on the twig is more often lengthwise than crosswise and 
the number may be as great as the bark will accomodate. (See Fig. 
2 e.) The color changes at this time from a light green to light brown. 
It is very doubtful if any nourishment is taken from this time till the 
spring activities begin. The mortality, outside of parasitism, during 
this period is considerable and varies greatly with different twigs and 
trees. The check twigs counted from trees in Denver showed this to 
vary from twenty-five to sixty-two per cent. 
SPREAD OF THE INSECT 
But few instances of the transportation of the insect have been 
observed, and these are of such a nature as to account for but a small 
portion of the infestation. The most fruitful source in the past has 
doubtless been through the transplanting of trees, for this is done 
when the insect is firmly attached in the hibernating stage. Over short 
distances they may be transported on the feet of birds or clinging to the 
parts of insects. The eggs hatch during summer when there is little 
migration among birds so that great distances are probably not made in 
this way. It is not probable that many migrations of this kind arc 
made in the fall when the insect is moving from the leaves to the twigs, 
since the insects at this time are probably too large to be readily carried 
by these means. Either the newly hatched young or gravid females 
may be transferred from tree to tree by the interlocking of limbs or by 
