HESSIAN FLY. 
13 
insect, the damage has only here and there been to the amount that 
was to be feared from what has taken place in other countries. 
No damage has hitherto been reported on the young Wheat or 
Barley; the accounts of attack are limited to injury to plant when 
running up in stalk, and in this condition, although much injury has 
in some cases occurred to Barley, Wheat appears to have done what is 
called “resist” attack, and strong firm stems of good sorts well 
cultivated not to have elbowed down, or to have suffered but little 
under the attack of the pest. 
In the following pages I have endeavoured to class the information 
sent in during the past season under the following heads :— 
First appearance of the perfect fly (male and female) from “flax¬ 
seeds ” preserved from last autumn’s British crops. 
First appearance of attack on the crops. 
Observations of appearance of the pest on Wheat and Barley, 
which I have arranged in order of date, and under the heads of the 
countries in which they occurred, viz., England and Scotland. 
Observations on other points which have been investigated, as 
examination of imported straw and sweepings of ships; non-presence 
of Hessian Fly attack on Oats; information regarding the species of 
parasites which have been identified as found in Britain; kinds 
of Wheat which have been reported as not suffering much under 
attack, &c. 
These observations are arranged for convenience of reference under 
their respective headings, and two maps are added, showing the 
districts known to be infested both in England and Scotland. 
Life-History of Hessian Fly. 
For such as may not have studied the nature of Hessian Fly attack, 
it may be desirable to mention that where the attack occurs (as it 
mostly does with us) to the growing stalk, the white legless maggot 
feeds outside the stalk, but inside the leaf-slieath just a little above one 
of the knots. Commonly it is just above the second knot, but the 
attack may occur lower down at the first knot, or close to the root, or 
higher up above the third or fourth knot. 
The mark of attack being present is the stem elbowing sharply 
down just above where the maggot lies. It does not commonly break, 
but, unless the straw is very firm, it bends at the weakened spot, and 
thus damage is caused to the fallen head, besides difficulty in reaping 
from the confused state of the straw. 
It appears from Dr. Lindeman’s careful observations in Russia 
that the larva (or maggot) lives about twenty-eight days in this 
condition. Then it changes at the precise spot at which it fed to a 
