HESSIAN FLY. 
37 
parasites have been notably observed to be present; and during the 
past season attempts have constantly been made, with greater or less 
success, to identify them, and thus, by finding whether they were of 
the kinds known to infest Hessian Fly in Russia or in America, to gain 
a clue as to whether it was from Russia or America that the attack 
came of the insect whereon they feed, viz., the Hessian Fly. 
Up to the end of October, however, no certain conclusion had been 
arrived at, as most of those concerned (so far as I am aware), and 
myself amongst the number, identified, or endeavoured to identify, 
solely from published description, without knowledge gained from 
personal examination of either American or Russian specimens. Our 
best guidance was from the information kindly given by Prof. Riley, 
Entomologist of the Department of Agriculture of the United States, 
who, after long and careful examination of British specimens, at which 
I had the advantage of being present, stated that none of those sub¬ 
mitted to him appeared to agree with specimens of the kinds known to 
him as North American ; and that the points laid before him regarding 
the attack inclined him to consider it of European rather than American 
origin. I also myself, so far as I could form an opinion in such a 
difficult matter, have already mentioned that one of the specimens 
appeared to me to agree in essential points with the Russian Semiotellns 
nigripes, Lind. 
Under the difficulties of identifying from description alone, I for¬ 
warded a small collection of parasites (bred from “flax-seeds” saved 
from the infested corn of the year 1886 by Mr. D. Taylor, of Daleally 
Farm, Errol, N.B.) to Dr. Charles Lindeman, Professor at the Academy 
of Agriculture, Moscow, who has devoted much attention to the study, 
both practical and scientific, of Hessian Fly in Russia, and has 
especially studied and written upon the subjects of its hymenopterous 
parasites. These specimens Dr. Lindeman had the great courtesy and 
kindness to examine carefully, and on the 31st of October I received 
the following communication from him, announcing that four of the 
five kinds he had examined were Russian; and with his letter he also 
sent a small collection of Russian specimens, truly valuable for our 
British service. Dr. Lindeman wrote me as follows :— 
“ I now hasten to attend to your communication sent to me with 
the parasites of the Cecidomyia destructor, and I have found the following 
species :— 
“1. Semiotellus nigripes , L. 
“2. Tetrastichus Rileyi, L. 
“ 3. Merisus intermedins, L. (var. micropterus). 
“ 4. Platygaster minutus, L. 
“ Along with these Russian species I find an example of what I am 
inclined to consider to be the American Merisus destructor. At least, it 
