674 
Journal of Agricultural Research 
Vol. XXX, No. 7 
Table VI.— Summary of examinations of gipsy-moth eggs collected around the 
“ observation points ” 
Num- 
Number of clusters 
Eggs parasitized 
Total para- 
Year 
ber 
of 
points 
collected 
By Anastatus— 
By Schedius— 
sitized— 
Total 
para- 
of 
collec¬ 
tion 
Large 
Me¬ 
dium 
Small 
Total 
Large 
clus¬ 
ters 
Me¬ 
dium 
clus¬ 
ters 
Small 
clus¬ 
ters 
Large 
clus¬ 
ters 
Me¬ 
dium 
clus¬ 
ters 
Small 
clus¬ 
ters 
By 
Ana¬ 
status 
By 
Sche¬ 
dius 
sitism 
1912-13. 
77 
1,131 
1,127 
1,102 
3,360 
P.d. 
0.207 
P. d. 
0.19 
P.ct. 
0.28 
P.d. 
0.33 
P.d. 
0.50 
P.d. 
0.64 
P.d. 
0. 21 
P.d. 
0.43 
P.d. 
0.64 
1913-14_ 
73 
1,068 
1,090 
1,053 
3,211 
.718 
.87 
.23 
1.09 
1.19 
1.54 
.85 
1.20 
2.05 
1914-15_ 
69 
1,069 
1,067 
1,048 
3,184 
.93 
1.13 
.93 
.83 
.97 
1.16 
.99 
.93 
1.92 
1915-16_ 
66 
1,037 
1,050 
1,046 
3,133 
2. 33 
2.86 
2.91 
1.36 
1.21 
1. 57 
2.62 
1.35 
3.97 
1916-17_ 
64 
921 
1,015 
1,001 
2,937 
4.36 
5. 27 
6.46 
2.36 
2.77 
3.31 
5.01 
2.66 
7. 67 
1917-18_ 
68 
792 
1,034 
981 
2,807 
6.19 
7.69 
9.54 
2.30 
2.83 
4.18 
7. 26 
2.78 
10.04 
1918-19_ 
64 
890 
913 
852 
2,655 
9.25 
10.22 
10.75 
.11 
.09 
.21 
9.83 
.12 
9. 95 
1919-20_ 
49 
439 
730 
731 
1,900 
9. 75 
11.16 
12. 53 
.50 
.58 
.92 
10.84 
.61 
11. 45 
1920-21_ 
49 
667 
742 
694 
2,103 
15.57 
17.85 
19. 56 
.03 
.07 
.13 
16.98 
.06 
17.04 
1921-22_ 
51 
357 
708 
695 
1,760 
25.03 
28.60 
31.20 
.09 
.12 
.23 
27.86 
.13 
27.99 
1922-23.._ 
49 
351 
758 
333 
1,442 
17.22 
24. 25 
30.10 
.98 
.85 
1.12 
21.94 
.93 
22.87 
1923-24 «_ 
17 
119 
359 
104 
582 
18. 51 
23.02 
30.35 
.71 
.52 
. 17 
22.18 
.55 
22.73 
1923-24 «_ 
60 
560 
1,403 
389 
2,352 
16.32 
20.00 
26.78 
.33 
.32 
.21 
20.96 
.29 
21. 25 
° A uniform method of collecting and examining the eggs was followed during the years from 1912 through 
the spring of 1923. The infestation was so light over much of the area during the fall of 1923 and spring of 
1924 that the collections had to be made over a larger area around some of the points. The examination of 
the eggs from 17 of the points was made in the usual manner. A slightly different method was used for the 
examination of the eggs from 60 points for 1923-24; the results for the two methods are separately presented. 
most of the towns on Cape Cod and 
along the northwest coast of Buzzard's 
Bay. Good records of parasitism by 
Schedius are often obtained from gipsy- 
moth eggs collected at Martha's Vine¬ 
yard and from the northeastern part 
of Rhode Island. 
Each fall a survey is made of the 
towns in the southern part of Massa¬ 
chusetts and collections of masses of 
gipsy-moth eggs are made from road¬ 
side and woodland trees. The percent¬ 
age of parasitism by Schedius of these 
collections has increased each year to 
and through the fall of 1922. The 
examination of the eggs collected in 
the fall of 1922 gave the following per¬ 
centages of parasitism for the towns 
named: Sutton, 35; Dartmouth, 36; 
Marion, 37; Mashpee, 18; Harwich, 26; 
North Harwich, 46; and Woods Hole, 
48. Collections of eggs made during 
the fall of 1923 showed the parasitism 
to have fallen a few points, but it is 
still considered good. 
SUMMARY 
Two egg parasites of the gipsy moth 
have been established in America/ 
Schedius kuvanae Howard, a species 
which had never been described until the 
project of gipsy-moth and brown-tail 
moth investigations was started, was 
introduced from Japan, its only known 
habitat. The other species, Anastatus 
bifasciatus Fonsc., came from Japan 
and from several parts of Europe. 
The biology of the two species varies 
greatly, Schedius having several gene¬ 
rations and hibernating as an adult, 
while Anastatus has but one generation 
and hibernates as a full-fed larva 
within the egg of the gipsy moth. 
Both species are slow-spreading para¬ 
sites and considerable colonization 
work remains to be done before they 
will have the same distribution as the 
gipsy moth in the Northeastern States. 
Anastatus was established by liberat¬ 
ing the imported parasites, and its 
colonization has been continued each 
year by collecting its host's eggs in 
New England and separating the para¬ 
sitized eggs from those containing 
gipsy-moth larvae. A total of 54,345,- 
193 Anastatus have been colonized. 
Schedius was established by breeding 
a relatively few adults received from 
Japan through several generations until 
enough adults of the parasite were 
obtained to warrant making liberations. 
It has been colonized in each succeed¬ 
ing year by breeding it through several 
generations at the laboratory, after 
having obtained the breeding stock 
from gipsy-moth eggs collected in New 
England. A total of 20,799,537 adult 
Schedius have been colonized. 
The data which have been obtained 
and presented in this bulletin show that 
Anastatus is now an important egg 
parasite of the gipsy moth in the area 
in which it has been generally colonized 
in New England. 
