permit specific identification of the host trees. On the other hand, the omission of such records would 
mean the loss of certain information which is valuable in other respects. 
In its present form this report is nothing more or less than a straightforward compilation of 
certain basic data on the macro- and microlepidoptera and their parasites, obtained through the Forest 
Insect Survey in the southern part of Ontario between 1937 and 1948. No attempt at analysis or synthesis 
has been made beyond the listing of foodplant and parasite relationships. Records of yearly fluctuations 
in abundance of many species must be taken with a grain of salt; they may or may not represent true 
conditions in the forest because in the majority of cases the samples submitted were qualitative rather 
than quantitative in nature and their significance depends, to some extent, on the keenness and the 
enthusiasm of the individual collector. 
Notwithstanding these recognized deficiencies, the report is worth publishing because it contains 
a considerable amount of new information on insect distribution, a great number of new records of host- 
parasite combinations and quite a good list of foodplants. As such, it should be particularly useful to 
systematists and students of insect parasites. When the data, here presented, will become integrated in 
the projected general technical report for the whole of Canada, their value to forest entomologists and 
ecologists will be more evident. 
I 
Division of Forest Biology, 
Science Service, Department of Agriculture, 
Ottawa. 
