ENR Se: 
' THE LESSER PEACH BORER. 39 
TABLE I.—Measurements of the head of the larva of Synanthedon pictipes in 
each of the six instars. 
FE. II. Iil. EVs Vi 88 
mm. mim. mm. mm, mm. mm. 
LGN e A a ee 0. 27 0. 55 0. 86 1.18 1.53 1.94 
0 EE nea APS OB SASS peas areneae (a) (b) 0.72-0.95 | 1.02-1.25 | 1.36-1.70 | 1. 84-2. 64 
BMOTOMCO’. ooo. 3 anise oe pe Lh Sg ee ee sed RE ee en ee Ae 0. 23 0. 23 0.34 0. 80 
« Constant. ’Not obtained. 
After hatching the young larva enters the tree by the way of a 
crevice and soon begins to feed on the soft living tissues. It grows 
rather rapidly and makes an irregular burrow between the living bark 
and wood of the tree. This channel, in time, becomes filled with 
— semiliquid gummy exudations and the reddish frass of the larva. 
Where the larva enters there is left a small pile of fine reddish wood 
dust. It is partial to wounds or diseased areas on the trunk, but, as 
formerly stated, may occur anywhere on the tree, from the crown of 
the root to the larger branches, and thus may be found feeding side by 
side with the peach borer. 
In confinement the larve will feed readily and grow on fresh 
pieces of peach bark; Mr. Quaintance has fed one for several days 
on peach leaves. When young, they are able to suspend themselves 
with silk, and Bailey (1879) has observed them “ drinking ” moisture. 
After the larva attains full growth and is ready to pupate, if some 
distance from the edge of a wound or crack, it cuts a hole through, 
or nearly through, the outer bark, and constructs a cocoon under this 
in a suitable cavity, so that its anterior end is against the opening. 
If it is near the edge of ruptured bark, which is more commonly the 
case, the cocoon is made just within the boundary of the wounded 
area, so that the pupa easily pushes out when ready to issue as an 
adult. In old peach trees with cracked bark the cocoons are usually 
found in this position. 
The cocoon is constructed of pieces of bark chewed into fine bits, 
frass, and silk secreted by the larva, and is light yellowish brown in 
color and soft to the touch. An old cocoon, however, is dark in color, 
and hard and brittle. The size of the cocoon varies, but it is always 
several millimeters longer than the pupa which it incloses. 
The pupa—tvThe larva, having formed a cocoon and inclosed itself 
within, waits several days and then pupates. The pupa (fig. 10, @) 
is brownish yellow in color, darker at the edges of the segments, 
sutures, head and wing covers, spindle-shaped, and is’ broadest at 
the first abdominal segment. It has all the characters normal to its 
family. The sete are sparse and minute. The spines on the first 
abdominal segment are very weak; in the female there is but a single 
