28 
CORN. 
extensile tip, which showed extremely plainly in Mr. Fitzgerald’s 
specimen. 
The life-history is stated to be for the parent sawfly to pierce the 
corn-stern and lay an egg within it. The maggot which hatches feeds 
within the tender straw, and, according to strength or circumstances, 
pierces through one or more knots, until when nearly full-grown it goes 
down again, and just about harvest-time cuts the straw through, or 
nearly through, with its strong jaws just about ground-level. It then 
goes down into the part below the cut, and there makes itself a kind 
of silken case (as observed at p. 27 by Col. Eussell), in which it 
changes to the chrysalis-state, and from this the four-winged fly 
(figured at 1, p. 26) comes out in the following summer. The colours 
are chiefly black and yellow; the yellow is clearest and brightest in 
the male. 
The damage is only partly caused by the sawing through of the 
stems. This causes them to fall, and makes confusion in the crop; 
but the great mischief is from the feeding of the maggot in the stem, 
having more or less stopped the proper formation of the ear. In the 
specimens sent me the marks and state of the stem showed very 
plainly where the maggot had been working within it. 
As the maggot remains in its silken case down the pipes of the 
stubble left on the field, and the fly does not come out until the early 
summer of the following year the means of preventing reccurrence 
of attack are very easy. If the stubble is scarified or skimmed so as 
to loosen it, and the plants then dragged and collected in heaps and 
burnt, the mischief is entirely put an end to. It would be worth 
while, where attack has been bad, to have the stray plants of stubble, 
which may have been left by the regular farming operations, hand- 
collected and thrown to the heaps for burning. 
In this, as well as in Hessian Fly attack, it would be a most 
excellent way of getting rid of infestation, if the thing could he 
managed, to burn the standing stubbles after harvest. But the plan is 
difficult to carry out in this country for many reasons. 
SCEEENINGS. 
Com Insects of various kinds. 
During the enquiries which followed on the first appearance of the 
Hessian Fly in this country during the past season, as to the possible 
methods by which this pest could have come amongst us, I was 
strongly urged to endeavour to direct attention to the great risk that 
is incurred of insect corn-pests being spread generally in consequence 
of the increasing use of screenings or injured corn, foul with all sorts 
