HESSIAN FLY. 
19 
whose researches on the Diptera are too well known to require any 
comment, and had from him the benefit of definite opinion that it was 
Cecidomyia destructor, Say. Further, I have had the opportunity of 
submitting the whole series of specimens to Mr. John Marten, of 
Albion, Illinois, U.S.A., one of the economic entomologists of Illinois, 
known by his papers on injurious insects, published in Eeports of the 
Department of Agriculture, U.S.A., and whose opinion is of much 
value, as having made a special study of the Hessian Fly. 
Abstract of Life-history. 
The following extract from a German source^' gives the main 
points of the life-history of the fly in Europe in short and plain 
form :— 
“ Cecidomyia destj'uctor, Say.—The larvse live in the haulm of wheat, 
rye, and barley. The female flies usually lay their eggs on the young 
leaves twice in the year,—in May and September,—out of which eggs 
the maggots hatch in fourteen days. These work themselves in 
between the leaf-sheath and the stem, and fix themselves near the 
three lowest joints, often near the root, and suck the juices of the 
stem, so that later on the ear, which only produces small or few 
grains, falls down at a sharp angle. Six or eight maggots may 
be found together, which turn to pupae in spring or about the end of 
July, from which the flies develop in ten days.”—Stett. Ent. Zeit., 
xxi., p. 320. 
Where does Hessian Fly come from ? 
The question now arises. Where does the attack of Hessian Fly 
come from ? It does not appear to have risen up gradually in the 
country, as we find it widely spread,—that is, in various parts of 
Scotland, as well as in one district of England,—without any obser¬ 
vation of its previous presence having been reported from any 
quarter, although the attack is of a kind which is very observable, 
and attention is given to insect injuries to the crops more or less in 
every part of the island. It may come in the “flax-seed” state in 
straw imported from any of the countries troubled by this pest ; it 
may be received from Canada, or from the United States, or from the 
South of Europe, Austria, Hungary, or Eussia. 
In respect to its importation in straw, it may come in straw- 
cargoes, or in straw used as packing material. Where this straw is 
sent forward to farms as it is, or as slightly-used litter, or as “ long ” 
manure, quite a sufficiently large proportion of the flies in the flax¬ 
seeds are likely to develop to cause mischief such as we have seen in 
* See Die Pflanzen feinde, von J. H. Kaltenbach. Stuttgart. 
