2 ‘MISC. PUBLICATION 188, U.S. DEPT. OF AGRICULTURE 
The Division of Preventing Spread of Moths, Bureau of Ento- 
mology, in operation at the time this work began, was divided into three 
distinct activities: (1) The quarantine and. inspection service, (2) the 
scouting and extermination work, and (3) the research projects. All 
employees in the field were instructed to collect and send to the labo- 
ae any interesting larvae that they found in the course of their 
uties 
When the Plant Quarantine and Conol Administration was estab- 
lished, July 1, 1928, the research projects were transferred to the 
Division of Forest Insects of the Bureau of Entomology, under F. C. 
Craighead, with C. W. Collins continuing directly in charge of this 
research work. ‘The cooperation has continued as heretofore, and 
each year the men working in the field have sent many collections of 
Insect material to the laboratory. Representatives of the several 
State organizations throughout the gypsy-moth-infested area and 
many oi the local superintendents of moth work and tree wardens in 
Massachusetts have cooperated by sending in material from time to 
time. As the result of this cocperation of the various agencies, an 
abundance of material was received from widely scattered localities 
throughout the Northeastern States. 
To cbtain data on dispersion of some of the introduced parasites, 
more especially Compsilura concinnata Meig., some special trips have 
been made from the laboratory to obtain collections of larvae outside 
of the gypsy-moth-infested area. 
From the foregoing the unusual opportunities offered for procuring 
material from New England, New York, New Jersey, and eastern 
Pennsylvania can be readily appreciated. 
The insects were received in all larval instars from newly-hatched 
to full-grown larvae and occasionally in the pupal stage. Many of 
the species were received during periods of abundance or during local 
outbreaks; often, perhaps, at a time when their parasites were at a 
low ebb. It must be understood also that many collections were 
received in a stage too early for attack by certain of their parasites, 
and other collections were made too late to obtain the parasites that 
issue from the earlier instars. Few pupal collections were received, 
so the parasites which normally attack their hosts while in the pupal 
stage are poorly represented in the lists. 
Insufficient material, in many cases, undoubtedly was the reason 
for the absence of parasites or for the fact that only a small number 
were secured from some of the host species. 
Anyone having had experience in rearing insects will readily under- 
Nand the difficulties encountered in handling so many larvae and of 
such varied types. There were some losses due to faulty methods of 
handling, to improper hibernation conditions, and, in no small degree, 
to disease. 
THE INSECT LISTS 
The host-parasite list, as summarized, includes under each host 
species (1) food plants; °2 (2) occurrence (this includes the specific 
localities from which it was received, except in the case of common 
2 The common names used for the trees were adopted from the following publication: SuDworTH, G. B. 
CHECK LIST OF THE FOREST TREES OF THE UNITED STATES, THEIR NAMES AND RANGES. U.S. Dept. Agr. 
Mise. Cire. 92, 295 p. 1927; and those for the shrubs and’ plants from the following: Britton, N. L., and 
BROWN, A. ANILLUSTRATED FLORA OF THE NORTHERN UNITED STATES, CANADA AND THE BRITISH POSSESSIONS 
FROM NEWFOUNDLAND TO THE SOUTHERN BOUNDARY OF VIRGINIA”. . . Ed. 2, rev. and. enl., 3 v., illus: 
New York. 1913. 
