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sires is of absolutely no value to the farmer. They eat just as much 
as if they were nor parasitized, and ir is really a matter of iirrle 
importance to the agriculturist whether the food that is stolen from 
him makes a moth or a fly. The caterpillar feeds all the same 
until it is full grown. 2s"ext year in the same field there will be just as 
many cutworms as there were in the previous year. The parasites have 
h:ept the number within the same limit, and the farmer has not been 
benefited. If he desires to save his crop he must himself adopt measures 
for the destruction of these insects: parasites will not help him in the 
least. Let us take another instance: One of the species of Tortricids 
infesting the Cranberries is very subject to the attacks of parasites, 
two species being abundant, and a third rare: yet every year the bogs 
suffer equally from this species. Lf we collect a large lot of larva? in the 
eaiiy spring we will find that very few of them will give out parasites. 
From the second brood we will breed a great many more, while of the 
third and last brood, probably 75 per cent will prove to be infested by 
parasites. This sounds very pretty, indeed, and we say that the insect 
has been controlled by its parasites, and so it has: but not until it has 
ravaged the bogs, and has done all the injury that it could do. It has 
destroyed the crop, and, seeing the enormous increase of the parasites 
during the year, the natural conclusion is. that they will next spring 
still further reduce the number of their host and bring matters to such 
a state that little or no further injury is to be apprehended. Yet. as a 
matter of fact, nothing of the kind occurs. We find that somehow 
during the winter the mortality among the parasites has been very 
much greater than it has been among the moths, and that just as in the 
previous year the first brood of moths will be almost exempt from the 
attacks of parasites. VTe will have on the bogs exactly the same his- 
tory that we found in the previous year. Of what practical benefit is 
this parasite to the farmer? It does not do anything in the world to 
prevent the destruction of his crop, nor does it in any way lessen the 
damage, for where these insects occur and are allowed to increase with- 
out check, except by their natural enemies, they appear in sufficient 
numbers each year to take the entire crop. This is not a solitary 
instance. It can be matched with ease in all our common insects. The 
Codling Moth, for instance, has parasites, and is doubtlessly kept in 
some check by them: yet every one present knows that if parasites and 
natural enemies alone were depended upon, farmers could not count on 
a single perfect apple. They do check the excessive increase of the 
insect, but they do not lessen in the least the number that can be sup- 
ported by the food plants. All the parasites that have been described 
from the Codling Moth, from the Plum Cureulio. and any others of our 
injurious insects do not benefit the farmer one dollar in the value of his 
crops, and I think it is well that this should be generally understood, 
because of the tendency that I have already mentioned to expect too 
much from the parasites. It must be remembered also that in the opera- 
