Apr. 1,1925 
Two Imported Egg Parasites of the Gipsy Moth 
669 
gipsy-moth eggs 1,000 parasitized eggs 
are put into small manila envelopes 
and stored in a cool place until the 
roads can be traveled in the spring. 
In some seasons the work of coloniza¬ 
tion has required a considerable force 
of men and auto vehicles in order to 
liberate the colonies in the limited 
time available. In several cases the 
various States have assisted greatlv in 
the work. 
The men are supplied with large 
blue-print maps (fig. 11) showing all 
roads in the towns to be colonized. 
Each man is given a supply of colonies 
and small tin cans (fig. 7, e, at right). 
Each can has three 3^-inch holes in 
its side near the top. All of the roads 
in each town are traversed and a 
colony of 1,000 Anastatus is liberated 
on each side of the road at intervals of 
a quarter of a mile, if there is wood¬ 
land area with sufficient gipsy-moth 
infestation to warrant such frequency. 
The colonies are placed 100 to 200 feet 
from the roadside. The can is nailed 
to a tree trunk in an inconspicuous 
place (fig. 2, /) and the parasitized 
eggs are poured into the can. A 
tight-fitting cover is placed on each 
can to prevent the rain and birds from 
destroying the colony. The location 
of each colony is marked on the blue¬ 
print map of the town (fig. 11). In 
each town two colonies in easily 
accessible locations are marked in the 
field by painting with white paint on 
a roadside tree a letter “A,” with 
arrows- pointing to the center of the 
colony (fig. 2, c). A note for filing at 
the laboratory is written, giving direc¬ 
tions so that the marked colonies can 
be easily located later. 
SUCCESS OF COLONIES AND DISTRIBU¬ 
TION OF ANASTATUS 
Collections of gipsy-moth eggs for 
data in regard to the establishment of 
Anastatus after colonization have shown 
that this parasite is easily established 
and recovered. Eighty to 90 per cent 
of the colonies liberated in Massa¬ 
chusetts, where collections of host eggs 
have been made later, have given 
proof of its presence. 
About 50 per cent of the collec¬ 
tions of gipsy-moth eggs which have 
been made in the other New England 
States showed the presence of the 
parasite. Anastatus has been re¬ 
covered from 161 towns in Massa¬ 
chusetts, 75 in New Hampshire, 20 
in Maine, 8 in Rhode Island, and 2 
in Connecticut, or 266 in all. 
Anastatus are now being found in 
gipsy-moth eggs sent to the labora¬ 
tory from practically every town where 
the species has been thoroughly col¬ 
onized. Figure 5 shows the area from 
which Anastatus has been recovered. 
It should be noted that the species is 
much more hardy than Schedius and 
is being recovered from the towns in 
the 1 *- northern part of the colonized 
area. 
PERCENTAGE OF ISSUANCE OF ADULT 
ANASTATUS FROM THE COLONIZA¬ 
TION CANS 
The contents of many coloniza¬ 
tion cans have been examined at the 
laboratory. Cans showing a low per¬ 
centage of issuance of Anastatus 
adults have occasionally been found. 
More than half of the cans which 
have been brought to the laboratory 
have shown that over 90 per cent of 
the parasitized eggs had yielded Ana¬ 
status adults. The average percentage 
of issuance is 68 for all the cans which 
have been collected. 
dispersion 
Very careful records were kept of 
the spread of Anastatus during the 
first years after its establishment in 
Massachusetts. Gipsy-moth egg clus¬ 
ters were collected along lines run 
in eight directions from the centers 
of several colonies. At first the egg 
collections were made at 50-foot inter¬ 
vals. Later, as the spread became 
greater, the collections were made 
along the lines at intervals of 100 
feet for the first 600 feet, and then 
of 100 yards to points well beyond 
the recovery of the parasite. The ex¬ 
amination of the eggs collected showed 
for the first year a spread of about 
200 feet, and for the second, 500 feet. 
Similar collections were made in 
the following years until later libera¬ 
tions of parasite colonies interfered 
with the data desired. These collec¬ 
tions showed that after a colony be¬ 
came well established the annual 
spread measured from its center was 
very much greater than it was in the 
first year or two. The data were 
obtained from five widely separated 
towns, and the spread was similar at 
each of the five colonies under ob¬ 
servation. An amazing increase in 
the rate of dispersion was noted as 
year succeeded year and the colonies 
became stronger. For the first year 
after the five colonies were liberated 
the spread from each center was 200 
feet, and for the second year 500 feet. 
For the third year the average spread 
was 890 feet, and the extreme spread 
