154 PARASITES OF GIPSY AND BROWN-TAIL MOTHS. 
GIPSY-MOTH CATERPILLARS, SECOND TO FIFTH STAGES. 
EUROPEAN IMPORTATIONS. 
The first importations of gipsy-moth caterpillars in the second to 
fifth stages were made in 1907. Small wooden boxes, each with a 
capacity of about 40 cubic inches, were used for the purpose, and 
all shipments were by mail. The caterpillars, usually to the number 
of 100, were inclosed in these boxes, together with several twigs 
bearing fresh foliage. 
The method was of doubtful utility, and at the same time no 
improvement upon it could be devised short of cold storage en route. 
On receipt the twigs would usually be stripped bare of foliage. Some 
of the caterpillars were invariably dead—whether from starvation or 
from injuries received at the time of collection or subsequently could 
not be determined. The remaining caterpillars were in all stages of 
emaciation and many of them, though still living, were too weak to 
recuperate. 
Parasites in considerahe variety but always in very small num- 
bers issued, for the most part en route, but occasionally from the 
caterpillars after receipt. Nothing could be decided as a result of 
these importations and their repetition was resolved upon. 
It was planned to import much larger numbers in 1908 without 
modifying the methods employed the year before. In this respect 
success was not achieved, principally, it would appear, on account of 
the difficulty of collecting these small caterpillars in numbers, espe- 
cially in localities where the gipsy moth was not very abundant. 
Furthermore, it became increasingly evident that the percentage of 
parasitism (so far as it could be determined by the actual number of 
parasites secured) was so insignificant as to make the task of import- 
ing sufficiently large numbers of any one parasite for the purpose of 
colonization wholly impracticable. Many of the lots of caterpillars 
which were received in the best condition produced no parasites at 
all. It was therefore evident that if extensive operations in any 
locality should be determined upon, complete failure might result 
through the absence of the parasites in that particular locality dur- 
ing that particular season. Nothing less than an improvement in 
the service of several thousand per cent over that of 1907 or 1908 
would answer, and this was altogether out of the question, except 
at an expenditure which even the generous funds appropriated by the 
State and Federal Governments could not cover. Further importa- 
tions from Europe were regretfully decided to be impracticable. 
