BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 81 
GYPSY MOTH CONTROL AND CERTIFICATION 
ACTIVITIES 
In May and June 1953 approximately 180,000 acres infested with 
the gypsy moth in Connecticut, Maine, Massachusetts, New York, 
Pennsylvania, and Vermont were sprayed by aircraft, and about 
6,970 acres by mist blowers. The work was in cooperation with the 
infested States. A small, isolated infestation discovered in Milford 
Township, Bucks County, Pa., in the fall of 1952 has apparently been 
exterminated as a result of spraying with DDT in May 1953. No 
other infestation is known to exist in Pennsylvania. 
Surveys conducted during the fiscal year involved more than 841,000 
acres. Most of the scouting was done in the vicinity of trap sites at 
which male moths were captured during the summer of 1952. There 
were 1,176 infestations located as a result of this survey. 
Observations during the 1953 larval period showed a marked in- 
crease in acreage of woodlands defoliated by the moth. Thousands 
of acres have been defoliated in western New England in the Con- 
necticut River Valley and adjacent areas from the Massachusetts State 
line to a point north of White River Junction, Vt. ; in isolated areas 
of eastern Massachusetts ; in the Lake Winnepesaukee section of New 
Hampshire; and in the Lake Sebago region and costal sections of 
Maine, including the Penobscot and Kennebec River Valleys. There 
appears to be heavy egg deposition in many locations adjacent to the 
defoliated areas. 
An appraisal of the gypsy moth problem was made during the 
summer and fall months of 1952 in cooperation with the United States 
Forest Service and collaborating State plant-pest officials. These 
studies clearly indicated an appreciable increase in gypsy moth abun- 
dance throughout the untreated infested area, and an extensive tree 
mortality and retardation of growth in areas defoliated by the gypsy 
moth on one or more occasions. A survey conducted throughout the 
Eastern States revealed an estimated 100 million acres of oak wood- 
land south and west of the regulated area which were classified as 
being highly susceptible to severe damage should the gypsy moth 
become established there. 
Experimental trap lines, used to study bait effectiveness and im- 
provement in its attractant efficiency, were continued during the 
summer of 1952. It was found that the bait strength of the standard 
field trap could probably be safely reduced from 15 to 12 female 
abdominal tips, should this become necessary to conserve attractant 
material. Other results proved that hydrogenated sex attractant 
material showed no sign of deterioration after 5 years' storage, that 
materials obtained from laboratory-reared moths proved highly at- 
tractive to male moths, and that the paper-cone trap now used in field 
surveys is the most efficient of many variations tested. 
Some investigation and some experimental work is being done by 
lumber dealers in the use of chemical weed-killers to keep storage areas 
free of weeds. Weed-free areas facilitate the drying of lumber and 
decrease the likelihood of female moths depositing egg clusters on 
lumber in storage. 
