CORN SAWFLY. 23 
in a cocoon within the lowest part of the stem, as mentioned at p. 21, 
it spends the winter (still in larval state) in this shelter. In the early 
summer it changes to the chrysalis state, from which the Sawfly comes 
out in time to lay her eggs on the corn; it is considered that one egg 
only is laid in each stem, the female fly continuing to lay on successive 
stems until her supply of eggs is deposited. Wheat and Rye are both 
subject to attack, and Barley occasionally suffers. 
One of my correspondents who was well acquainted with the 
appearance of the attack reported it in 1887 as present in Barley stems 
in the neighbourhood of Goring Heath, near Reading, but he observed 
that Oats were not infested, even when growing in the same field 
mixed with the Barley. 
The fly is of the shape figured at 1, p. 21, and about a third of an 
inch in length. The general colour black, varied more especially in 
the male with yellow. The antenne black and yellow. The flies are 
to be found in summer on grass in woods, and on flowers in corn-fields, 
and especially on those of umbelliferous plants. 
PREVENTION AND Remepies.—The maggot winters in its spun case 
in the lowest part of the corn-stem, at or below the ground-level, 
where it is left undisturbed by the falling of the upper part of the 
stem which it had cut through, and any method of destroying the 
stubble, in which it is thus harbouring, is an effectual method of 
clearing the infestation. 
This may be done by whichever of the common agricultural methods 
is preferred. All that is needed is to skim or loosen the surface, so 
that the lumps of stubble may be collected and gathered in heaps and 
burned. Common ploughing in is not to be trusted, for a great deal 
of the stubble would not be buried away deeply enough to prevent the 
fly coming up through the ground at hatching time. Some part of 
the infestation would be got rid of, but not all. Where burning the 
standing stubble can be conveniently managed, this is an excellent 
plan for killing the grubs, but this is so rarely done that there is risk 
of causing more harm than the good would counterbalance. Where, 
in case of bad attack, it is wished to try this plan, it may be safely 
managed in the Canadian method by firing the field first round the 
borders. Thus, instead of the fire going wildly where the wind may 
drive it, there is only a slight heat at first and a line of fire under 
control near the hedges. The fire thus spreads over the dry stubble 
towards the middle of the field, and the flames cannot return over the 
already charred surface. 
