October, ’20] 
PETERSON: ORIENTAL PEACH MOTH 
391 
many cases and since their resemblance is very close it is not surprising 
that the codling moth was believed to breed quite commonly in haws. 
In view of the fact that the wild hawthorns are hosts of many of our 
present apple, pear and quince pests and also of many potential insect 
pests, not to mention the cankers, blights and rusts which they may 
harbor, should we not remove them from the vicinity of our orchards 
or at least give them insecticidal treatment? The cumulative benefit 
iwhich would be gained from spraying an orchard several years in suc¬ 
cession may be lost if the surrounding country continually furnishes 
a new supply of pests. 
SOME STUDIES ON THE EFFECT OF ARSENICAL AND 
OTHER INSECTICIDES ON THE LARVIE OF THE 
ORIENTAL PEACH MOTH 
By Alvah Peterson, Assistant Entomologist , New Jersey Agricultural 
Experiment Station 
Introduction 
The oriental peach moth, Laspeyresia molesta Busck is found in 
several localities in New Jersey. It is particularly abundant in 
orchards about Red Bank and New Brunswick. The author has 
given this pest considerable attention for two seasons, 1918 and 1919.. 
During these seasons it has been noted that there have been at least 
three full broods and a partial fourth. The first larval injury to the 
twigs in 1919 was seen the first week in June at Mr. J. C. Hendrick¬ 
son’s three year old peach orchard (Hale variety) near Middletown, 
N. J., at that time no tree possessed over ten injured twigs. In 1918 
this orchard was severely infested. Some of the trees had over 90 per 
cent of the twigs injured during the month of July. During 1919 the 
infestation in this orchard was approximately 50 per cent less than 
in 1918. The last freshly injured twig observed in 1919 was found on 
August 30 in the orchard at the college farm. 
Twig injury to peach trees is most severe during the first three years 
after the trees are set out in the orchard. It has been repeatedly 
observed that in old orchards (five years or more) twig injury is not 
serious. Several old orchards have been examined which are adjacent 
to heavily infested young orchards and little or no twig injury could be 
found. It is apparent that the larvae prefer young, tender, vigorously 
growing shoots. 
The first fruit injury in 1919 was seen the last week in June while the 
last fruit infestation was observed on September 10 at New Brunswick. 
;So far as known, no fresh larval injury of any description has been seen 
