CORN SAWFLY. 
55 
tube, which is often partly filled with maggot-dirt. It makes its way 
along the whole of the inside of the straw by cutting a passage 
through the knots, and about harvest-time, when it is full-grown, it 
goes down the straw (always inside) to ground-level. There, with its 
jaws, it bites a ring round the straw (on the inside), so that presently 
the straw breaks and falls ; but the maggot lies secure in the short 
stump of stubble remaining in the ground, where it protects itself for 
the winter by spinning a covering, in which presently it changes to the 
chrysalis-state, from which the sawfly comes out early in the following 
summer. 
Much damage is sometimes caused by the attack, as the maggot 
gnawing within the straw injures the progress of the ear, and when the 
straw at last falls, this, of course, is hurtful to the harvest. 
Nothing at all can be done when attack is set up to remedy it, but 
recurrence (from obvious infestation) may be prevented by scuffling 
the surface, and dragging the stubble together and burning it. 
Ploughing the stubble under will destroy the maggot within, or at least 
prevent it coming to maturity and spreading infestation, if the stubble 
is well covered down, and not turned up again until July of the 
following year, when the time for the flies to come out is past; but as 
this is difficult to ensure, the simplest and safest plan is collecting the 
stubble and burning it. 
