PREVIOUS WORK WITH INSECT PARASITES. 23 
yet been reported upon, but theoretically speaking the experiment 
should have excellent results. 
THE TRANSFER OF BENEFICIAL INSECTS FROM ONE COUNTRY TO 
ANOTHER. 
EARLY ATTEMPTS. 
Dr. Asa Fitch, for many years State entomologist of New York, 
was probably the first entomologist in America, or elsewhere for that 
matter, to take into serious consideration the question of the transfer 
of beneficial insects from one country to another. In 1854, following 
a disastrous attack upon the wheat crop of the eastern United States 
by the wheat midge (Contarinia tritict Kirby), a species that had been 
accidentally introduced from Europe during the early part of that 
century, Dr. Fitch, who had made a careful study of the insect both 
in this country and from the European records, was struck with the 
fact that in Europe the insect in ordinary seasons did no damage, and 
that when occasionally it became so multiplied as to attract notice it 
was but a transitory evil which subsided soon and was not heard of 
again for a number of years. He was aware that in Europe certain 
parasites of this insect were found, and, comparing the insects taken 
from wheat in flower in France with those taken from wheat in flower 
in New York, he found that in France the wheat midge constituted 
but 7 per cent of the insects thus taken, while its parasites constituted 
85 per cent; whereas in New York the wheat midge formed 59 per 
cent of the insects thus captured, and there were no certain parasites. 
He speculated as to the cause for this extraordinary difference and 
wrote: 
There must be a cause for this remarkable difference. What can that cause be? 
I can impute it to only one thing; we here are destitute of nature’s appointed means 
for repressing and subduing this insect. Those other insects which have been created 
for the purpose of quelling this species and keeping it restrained within its appropriate 
sphere have never yet reached our shores. We have received the evil without the 
remedy. And thus the midge is able to multiply and flourish, to revel and riot, year 
after year, without let or hindrance. This certainly would seem to be the principal if 
not the sole cause why the career of this insect here is so very different from what it is 
in the Old World. 
Quite naturally after this train of reasoning had entered his brain, 
Dr. Fitch made an effort to introduce the European parasites of the 
wheat midge, and in May, 1855, addressed a letter to John Curtis, 
the famous English economic entomologist, and at that time president 
of the Entomological Society of London, informing him of the immense 
amount of damage done by the midge in America and suggesting the 
‘manner in which parasitized larve could be secured in England and 
transmitted alive to this country. Mr. Curtis was ill and on the point 
of starting for the Continent, but laid the letter before the Entomolog- 
ical Society of London, which resulted in the adoption of a resolution 
