F. M. CAMPBELL-THE HESSIAN FLY. 
191 
with stronger straw, on a field of good soil, was not supposed to be 
attacked, so well it looked, and yet was found on threshing to con¬ 
tain more puparia than any other. Of course, had seasons like 
1886 reduce the vitality of every plant, hut so far the limited 
English experience has been the same as the wider one of America, 
viz. that a healthy plant, grown on good soil, may he sufficiently 
strong not to suffer from the withdrawal, by one or two larvae, of a 
portion of its sap. Further, the stronger stem may, in addition, 
offer a resistance to their rudimentary mouths and anchor, in the 
same manner that the thicker-cuticled American vines appear to 
partly withstand the attacks of the Phijlloxera vastatrix. But 
whatever consolation such considerations may encourage, we must 
not forget that, notwithstanding all the knowledge of the Americans, 
the loss occasioned in 1885 * by the Hessian fly in the State of New 
York was £26,000, and was much more severe in some other States. 
Every practicable precaution will of course always have to he 
taken against every pest, hut it appears that the vigour and in¬ 
trinsic health of the particular plant attacked are its best safeguards. 
There always will he pests, and that plant will come out best in 
the end which can best endure the bleeding of its natural sap. A 
strong plant may produce well, after having suffered depletion that 
would have destroyed a weaker plant. 
Geneeal Obseevations. 
It is a strange coincidence that the wheat-midge (Cecidomyia 
tritici , Kirby), like the Hessian fly, was first observed in Hertford¬ 
shire (1795),f and it was only two years later that Kirby wrote 
that he had not examined in his walks any ear of wheat which 
was “not inhabited by these larvse.” J It is unnecessary to detail 
the constant injury done to the crops by that insect. It is to he 
hoped that the same will not he said of the Hessian fly. I am no 
alarmist, hut must hold that a serious danger threatens us. It 
would he well if the members of our Society were not only to 
ascertain if the new pest had visited their neighbourhood, hut 
also to make known the precautionary measures which should be 
adopted. 
I am inclined to think that the Hessian fly has been com¬ 
paratively recently introduced into the United Kingdom, for it 
could scarcely have escaped the enquiries of Sir Joseph Banks, 
Kirby, Curtis, and other entomologists. The only evidence I have 
which hears upon the length of its settlement with us is that 
of a farmer at St. Margarets, who told me that, just before harvest, 
twenty-five years since, at Mary Hill, Glasgow, having accidentally 
observed a puparium in wheat, he was led to examine the stalks 
of sickly ears, in which he found others. He correctly described 
to me the puparium and its position, and on my showing him one 
in situ , stated that those he had seen were the same, but of a 
* ‘Report of President of-Entomological Soc. of Ontario,’ 1886. 
f ‘ Trans. Linn. Soc.’ vol. iii, p. 242. 
X Op. cit. vol. iv, p. 231. 
