38 
CORN. 
is distinguished from my Merisus intermedins by the form of the body 
and brown shanks, and agrees well with the description by Riley.” 
The first four of the above parasites being Russian kinds, points to 
our attack of the Hessian Fly, on which the maggots of these insects 
feed, being certainly in part from Russia. 
Whether the presence of the Semiotellus (or, as it is now called, the 
Merisus ) destructor of Say, points to some part of our attack coming 
from America, does not appear to me so certain, because, although 
this is without doubt an American insect, it has also, under the 
synonym of Ceraphron destructor, Say, been recorded as parasitic on the 
Hessian Fly in Germany; and therefore it appears to me that this 
parasite may have come to us either from America or Germany. 
Therefore the case stands at present that it is certain that four of the five 
kinds, which have been trustworthily identified, are Fiussian, and it is very 
possible that the ivhole of the attack has come from the Continent of Europe. 
On the 22nd of November Prof. Riley further wrote me that he had 
given two whole days to the examination of Hessian Fly parasites 
reared from British puparia, together with a collection of specimens of 
Russian parasites sent him by Dr. Lindeman, with the result that 
all the conclusions he had previously arrived at were confirmed. I 
give the list (by kind permission) of the species identified by Prof. 
Riley, which it will be seen includes the four species noted above which 
I had forwarded to Dr. Lindeman, and which were named by him as 
Russian, and likewise three other Russian forms :— Semiotellus nigripes, 
Tetrastichus Rileyi, Merisus intermedins, Platygaster minutus, Eupelmus 
Karschii, and Euryscapus senilis, all. species of Lindeman; likewise 
Dacnusa senilis, Hal. (not a Chalcid). Thus Prof. Riley remarks, 
“ Every one of Dr. Lindeman’s forms have been reared in England, 
but I should not have been able to speak so positively without his 
types, which he has been kind enough to send me.”* 
Those who desire the latest and fullest information regarding these 
parasites are referred to a paper by Prof. C. V. Riley, Entomologist to 
the Department of Agriculture of the United States, “ On the Parasites 
of the Hessian Fly,” published in the ‘ Proceedings of the United 
States National Museum,’ 1885, pp. 413-422, one plate. Also ‘Die 
Pteromalinen der Hessenfliege’ [Cecidomyia destructor , Say), by Prof. 
Lindeman, Moscow, 1887. 
* As I have Prof. Riley’s kind permission to give the information with which he 
furnished me, it may be of interest to some of the Hessian Fly observers to mention 
that he considered the Semiotellus nigripes, Lind., would probably be found 
synonymous with Entedon epigonus , Walker ; that Euryscapus sallator, Lind., was 
Euryscapus Degeeri, as determined by Mr. Marshall; and that there were great 
varieties in the forms of Merisus intermedius; but as I believe that we may look 
forward to aid from Prof. Riley’s skilled pen and pencil in putting the whole series 
of British parasites in order before us, I do not add more from the short notes he 
has kindly given me. 
