192 
F. M. CAMPBELL — THE HESSIAN ELY. 
brighter red colour. This could be explained if they had been 
recently formed. But he added that he had found them also on oats 
during the same year. Now, as already mentioned, all observers 
agree that the Hessian fly does not attack oats, and this leads me to 
think he must have been mistaken. The question arises,—Whence 
has it come ? The answer can only be speculative. It is more easy 
to form an opinion as to. the means of its introduction. There is a 
great quantity of straw imported as straw, and also in manure; * and 
it is used also generally for packing. It is impossible not to admit 
how easily the puparia or flax-seeds could, in such manner, be 
conveyed—first to our ports, and then all over the country. Miss 
Ormerod, to whom agricnltnrists are already much indebted for the 
publicity given to the remedies against injurious insects, informs 
me that, having organized a search amongst imported straw at our 
ports, she has received and identified one puparium of the Hessian 
fly which came from Belgium. At the same time her correspondents 
in that country, and in the Netherlands, inform her that the Hessian 
fly has not yet been discovered there. 
The new indenization of any animal is of the greatest interest to 
a naturalist; but, independently of this general view, there are 
points connected with Cecidomyia destructor, Say, on which further 
information is required. I refer more particularly to— (a) Whether 
wheat, barley, and rye are the only food-plants of its larvae ? In 
other words, are these cereals the essential, or only the preferred 
nidi ? (b) The identification of its parasites; and (e) Whether the 
larvae, like others of the same genus, are capable of agamogenetic 
reproduction ? 
The injury inflicted on our crops by this insect pest may as yet 
be comparatively slight, but with the knowledge of its devastations 
in America, we should be more than careless if we neglected pre¬ 
cautionary measures. 
[I regret to add that the C. destructor now (July) infests every 
barley and wheat field in this parish (Hoddesdon), and I have found 
it on farms in Hertford, Ware, Stanstead, Amwell, St. Margaret’s, 
Broxbourne, Wormley, Cheshunt, and Stanstead Mountfitchet, near 
Bishop’s Stortford. The puparia in the wheat are situated just 
above the first joint, and sometimes at the crown of the root,—and 
these will therefore remain with the stubble. Early ploughing 
would be of considerable service. Some Americans recommend 
feeding off with sheep, under the impression that the puparia 
would be trampled on. Barley is attacked more than wheat, and 
I have found as many as seven puparia on one stem.] f 
* Mr. G. E. Palmer informs me that large quantities of manure from London 
have been used on Eevell’s Hall Farm for the last five or six years : some of the 
straw may have been imported. 
f The figures illustrating this paper are kindly lent by Miss E. A. Ormerod, from 
her pamphlet on e The Hessian Fly.’— Ed. 
