392 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 13 
after this date in New Jersey. Fruit injury to peaches has seldom ex¬ 
ceeded 10 per cent of the crop in any orchard in this state. In most 
orchards it was much less than 10 per cent. This pest has also been 
found attacking the fruit of apple and quince trees in New Jersey. 
Entomologists in other states have recorded injury to cherry, plum 
and apricot trees and also to ornamental fruit stock. 
The larva, when it hatches from the egg is very small, somewhere 
between 1-2 mm. in length. When it is full grown it measures 12-13 
mm. in length. The larva usually enters a growing peach twig at its 
distal end; however, it may make its way into the shoot near the base 
of a leaf petiole or the point of entrance may be the petiole itself. 
Before it enters it usually spins a loose silken cocoon about its body. 
The silken threads close the open spaces between the leaves at the 
point where the larva enters. Larvae that are half grown or larger 
seem to be more inclined toward spinning a loose cocoon before enter¬ 
ing than very small larvae. Usually before the silken cocoon is com¬ 
pleted the larva proceeds to bite out pieces of green tissue from the 
stem or small leaves and places these particles on the thin web about 
its body. The green particles soon dry and turn brown, thus making a 
collection of brown frass at the point of entrance. 
So far as known, the larva does not consume any of the outer green 
tissue of the twig at the point where it enters. It, apparently, waits 
until it is within the stem before it partakes of food. The above fact 
seems to be true of all larvae, particularly those that are half grown or 
larger. Other investigators have also recorded the above observations 
in respect to the feeding habit of the larva. Since the larva fails 
to consume the outer green tissue as it enters a shoot this probably 
accounts for our failure to obtain a satisfactory control in orchard 
experiments with arsenical sprays in 1918. 
One larva may enter several growing shoots, three or more, before 
it obtains sufficient food to complete its larval development. This 
fact, in part, accounts for the large number of injured twigs one may 
observe on a heavily infested tree and yet find comparatively few 
larvae. 
Larvae also enter the fruit of peach trees. Many of them go into 
the fruit near the stem end, but they also enter the sides of the peaches. 
The larvae usually deposit a mass of green tissue at the point of 
entrance on the fruit. Here again the larvae, apparently, do not 
consume their first mouthfuls of peach tissue. 
Experiments 
During 1918 a number of severely infested trees were carefully 
sprayed with arsenical mixtures of varying strengths. In no case 
were we able to get over a 50 per cent reduction in the number of 
