12 
Psyche 
[March 
Having thus bared a very pessimistic attitude and ex- 
posed to view what you have doubtless recognized as the 
clear, clinical picture of an inferiority complex, let us re- 
turn to some purely entomological phases of the matter. 
How do the several types of food-habits among vegetarian 
insects affect their pracitical importance in relation to the 
human food supply? It is generally conceded that mono- 
phagous and oligophagous types are the ones most destruc- 
tive to cultivated crops. We can at once recall a long series 
of such species, the potato-beetle, the codling moth, the 
oriental peach moth, and many others whose importance is 
due to the fact that they unerringly pick out valuable and 
widely cultivated agricultural plants. On the other hand, 
many with a considerable range of food-plants, the boll- 
worm, the corn-borer, the Mediterranean fruit fly, the melon 
aphid, the red scale and the like are very destructive, but 
quite generally less so on the whole, in spite of the much 
greater variety which may feed upon a particular species 
of plant. General feeders like the various types of locusts, 
army worms, etc., although very conspicuously destructive 
in some regions and on certain occasions, are in the long 
run less generally dreaded by agriculturists. To return then 
to our earlier discussion of monophagy and oligophagy, we 
must admit, without further ado, that our present civiliza- 
tion could well dispense with this interesting evolutionary 
phenomenon, since it is a gift of Nature that serves to in- 
crease injury to cultivated plants, at least under modern 
agricultural conditions. We might return the gift with 
thanks, but so far, science has been unable to write a suf- 
ficiently polite or forceful note to accompany the transfer. 
There is just one more matter relating to these destruc- 
tive insects which I hesitate to mention as it is so familiar 
to all of us. It was one of the first choice bits of information 
we acquired as students and we have religiously passed it 
on to our students ever since. The most destructive insect 
pests are those that have spread from their original habitat 
into some other faunal region. The reasons for this are 
usually said to be well understood on the basis of predatory 
and parasitic control, but there is much to suggest that 
other factors remain still to be elucidated. 
