Nov. 20, 1916 
Laspeyresia molesta 
377 
bined effect of the caterpillar and brownrot fungus, a good deal of fruit 
may fall to the ground, though the majority of the fruit infested by the 
caterpillars will remain hanging on the trees, especially if the fruit was 
invaded when nearly mature. If the peach be entered at the stem end, 
the larva as it grows makes its way to the pit, where it feeds on the flesh, 
which soon becomes much discolored and more or less slimy (PI. 31). 
Larvae entering at the side of the fruit are more likely to eat out pockets 
or cavities in the flesh, as shown in Plate 30, A. The inconspicuous 
entrance holes of the young larvae, especially at the stem end, often render 
it difficult to detect wormy fruit by exterior examination. In numerous 
cases apparently sound fruit when cut open has been found infested with 
one or more larvae. 
PUPATION AND HIBERNATION 
The caterpillar when full grown seeks some protected place where a 
cocoon of whitish silk is made preparatory to pupation. Cocoons in 
summer have been found in the cavity at the stem end of the fruit (PI. 
30, B), between fruits in contact, on or between mummified peaches, in 
leaves gummed to the twigs, or similar situations. * It is probable that 
many larvae find protected places on the twigs, in cracks, under bark 
scales on the trunk and branches, and in debris on the soil. During 
September larvae were frequently observed making their way into the 
cracks in the bark of the trunk and larger limbs of the peach, evidently 
seeking winter quarters. Winter cocoons have been found in a few 
instances in little cavities eaten into the bark at the tips of injured twigs 
and more or less protected by the dried exuded gum and attached leaf 
fragments. The larvae in general appear to be rather indiscriminate in 
their choice of pupation quarters and may be expected to choose any 
place on the trees where protection is afforded. Many larvae have been 
collected under bands of burlap wrapped around the trunk and larger 
limbs of the trees. In the case of nursery stock the absence of rough bark 
and other protection on the young trees probably forces the larvae to the 
ground, though a few individuals might find protection here and there on 
the plants. The insect hibernates in the full-grown larval condition in 
silken cocoons, pupation occurring in the spring. Owing to its manner 
of hibernating, the detection of the insect on nursery stock and young 
trees would be extremely difficult, and the disinfection of trees from the 
pest could be insured only by adequate fumigation with hydrocyanic- 
acid gas or other suitable substance. 
EMERGENCE OF MOTHS AND NUMBER OF GENERATIONS. 
Moths are out egg laying in the spring by the time the shoots of the 
peach are well out, as the work of the larvae is in evidence when the shoots 
are 6 or 8 inches long. It would appear that there are two and probably 
three broods of larvae each year, since injury begins early in the season, 
and larvae in various stages of growth are to be found in late fall. 
64312°—16 - 3 
