cy 
7 
Insects Attacking Ferns in the Hawaiian Islands. 
BY 0. H. SWEZEY. 
(Presented at the meeting of March 3, 1921.) 
In a recent paper by Dr. Charles T. Brues on “The Selec- 
tion of Food-plants by Insects, With Special Reference to 
Lepidopterous Larvae,” * he says, “The term phytophagous 
with reference to insects is commonly employed in a consider- 
ably restricted and rather inaccurate sense, including only those 
species that feed upon the higher plants, meaning by these the 
ferns and flowering plants. Only an extremely small, almost 
negligible, proportion subsist upon ferns, so that from a practi- 
cal standpoint, we would include only those feeding upon the 
Spermatophytes.” 
It is to be presumed that Dr. Brues has in mind conditions 
of his region, the Eastern United States, when he says an 
aimost negligible proportion of insects subsist upon ferns. Here 
in the Hawaiian Islands a considerable number of insects sub- 
sist exclusively upon ferns, besides quite a number of others 
which are more or less associated with them. 
During the seventeen years that the writer has been engaged 
in economic entomology in the Hawaiian Islands, the study of 
the habits, host-plants, life histories, parasitic relations, etc., of 
the endemic insects have received considerable attention as well 
as have the introduced insects which were of economic impor- 
tance. In becoming familiar with the endemic insect fauna 
of the Hawaiian Islands, one soon learns that the different 
species are largely attached to particular trees or plants, and 
conversely that each species of tree or plant has its own 
peculiar insect fauna—one or more species of insects which 
feed upon it exclusively. Following out this phase of the insect 
relations to the plants, much attention has been given to the 
study of the insect faunas of some of the more important 
native trees which seemed to have a larger insect fauna than 
many of the other species. 
Along these lines, the native ferns in the Hawaiian Islands 
have come in for their share of similar consideration. The 
Proc. Haw. Ent. Soc., V, No. 1, October, 1922. 
} * American Naturalist, LIV:313, 1920. 
