44 NEW YORK STATE MUSEUM 
FRUIT TREE INSECTS 
Gipsy moth (Porthetria dispar Linn.). An examination 
June 22, 1917 at Mount Kisco of an area where a gipsy moth 
infestation was discovered some five years ago revealed a very 
satisfactory state of affairs. The insect had spread over approxi- 
mately 175 acres on two large estates. During the past summer 
we were informed no caterpillars or living gipsy moth in any stages 
were found. Nevertheless, the entire infested area was thoroughly 
sprayed with arsenate of lead, using 10 pounds to roo gallons of 
water, the application being made with one of the modern high- 
power spraying outfits generally employed for woodland work in 
eastern Massachusetts. The general indications are that the colony, 
although larger than the earlier discovered one at Geneva, has like 
that been exterminated. 
Yellow-necked apple worm (Datana ministra Drury). 
This common leaf feeder, easily recognized by the conspicuous 
yellow mark just back of the head in connection with a scant 
hairiness and its black and yellow stripes, appeared in orchards 
the latter part of August or early in September and was reported 
from numerous localities throughout the State. The gregarious 
habits of these pests result in branches or even entire trees being 
rapidly defoliated, and as a consequence considerable injury is very 
probable on young trees. 
This pest is easily controlled by crushing the small colonies of 
caterpillars before they have had an opportunity of causing much 
injury, or general protection may be secured against this and other 
leaf feeders by spraying about the middle or the latter part of August 
with arsenate of lead or similar poison applied at the usual strength. 
Red-humped apple worm (Schizura concinna Sm. and 
Abb.). Colonies of this late leaf feeder began to appear in New 
York orchards about mid July and continued feeding through that 
month, August, September and even into October. These pests, 
like the yellow-necked apple tree worm, are gregarious in habit and 
consequently branches or young trees are very likely to be defoliated. 
This red-humped caterpillar is most easily recognized by the red 
head and the red humps just a little back of the head and near 
the posterior extremity. The full-grown caterpillars are about 
12 inches long. This insect was unusually abundant and destructive 
in many orchards throughout the State and occasioned considerable 
apprehension on account of its depredations. The pest is easily 
controlled by the same measures as advised above for the yellow- 
necked apple worm. 
