242 
PARASITES OF GIPSY AXD BROWN-TAIL MOTHS. 
Fig. 45.— Chalcis flavipcs: Female 
Hind femur and tibia, showing 
markings. Greatly enlarged 
(From Crawford.) 
ment of pupae from Japan, but the exact localities from which these 
shipments came is not known. 
Both are, or appear to be, invariably solitary, notwithstanding 
that there is an ample food supply in one pupa for several individuals. 
Invariably there is an abundance of unconsumed matter in the host 
pupa, and on this account the parasite has rarely been successfully 
reared from any of the imported pupse except the small males, in 
which this matter is in such small amount as partially to dry before 
receipt at the laboratory. In the large 
female pupae the decomposing contents of 
the pupal shell form a semiliquid mass, 
^Sj \ which is shaken about while the material is 
in transit, and completely overwhelms the 
larva or pupa of the parasite. The parasite 
is able to withstand this condition to a re- 
markable extent, but not to the extent fre- 
quently brought about by the unnatural 
conditions incident to transshipment. 
Partly on this account, but still more 
owing to the difficulties which have stood in the way of securing an 
adequate supply of gipsy-moth pupae in good condition from localities 
where Chalcis occurs, it has not yet been possible to colonize either 
the European or the Japanese species satisfactorily, nor, so far as 
known, successfully. Only a few hundred have been received, all 
told, since their status as primary parasites 
was first established in 190S. Had they all 
been of one species, received at one time, 
and colonized in the same place, there would 
be some reason to expect that the coloniza- 
tion would be followed by establishment. 
There were two species, however, they were 
not all colonized in one place, and coloniza- 
tion has extended over three years. The 
best and largest colony was liberated in 1909 
and strengthened by the addition of the 
small number received from abroad in 1910. 
A single specimen was reared from a lot of gipsy-moth pupae col- 
lected in the immediate vicinity of the colony shortly after it was 
founded in 1909, but none issued from similar collections made in 
1910. 
Both Chalcis Jlavipes and C. obscurata have been carried through all 
of their transformations in the laboratory on American pupae. The 
females are able to oviposit very shortly after emergence, and will do 
so with considerable freedom in confinement, making possible the 
artificial multiplication of either species were it possible to secure a 
Fig. 46. — Chalcis obscurata: Fe- 
male. Hind femur and tibia, 
showing markings. Greatly en- 
larged. (From Crawford.) 
