92 
PEAR. 
leaves when attacked soon turn brown, wither, fold, and drop as in 
winter.” 
On September 23rd, Miss Culverhouse wrote that the insects had 
largely increased in numbers, but that the remedies which I suggested 
(noted below) had been tried; and that the liveliness caused by the 
application of lime-dust, and consequent exudation of slime, soon 
disappeared on a second application, and their eradication soon would 
be complete. 
On September 15th specimens of this same kind of shiny cater¬ 
pillars were sent me from Serlby Hall, Bawtry, Yorkshire, with the 
observation that they had devastated a long wall of Pear trees, so that 
the leaves had turned quite brown and were falling off. 
The Slug-worm attack can be checked by dusting or syringing. 
The caterpillars, if annoyed by throwing a caustic powder on them, 
such as quick-lime or gas-lime, can throw it off at first by exuding a 
coating of slime, and thus as it were moulting off the obnoxious 
matter; but they cannot keep on continuing this process ; therefore a 
second application of the powder (of course soon after the first) takes 
effect and kills them. If a good time is allowed to elapse between the 
dressings, they will have regained the power to produce the slime 
exudation, and the dressing will do little good. Tobacco-water, lime- 
water, and syringings are all stated to be of service, but it is desirable 
the syringings should be applied early or late, as before 7 o’clock in 
the morning or 5 in the afternoon. 
The recurrence of the attack, which, as it will have been observed 
in the above notes, is a very common circumstance, may be prevented 
by skimming off the surface of the ground and removing the cocoons. 
These may lie below the surface at from one to about four inches deep, 
according to the state of soil. If the earth is stirred over by a competent 
observer, little balls, probably much resembling the colour of the earth 
they are in, will be found, and may at once be identified by just tearing 
the spun case open, when the caterpillar or, later on, the chrysalis will 
be found within. When once the observer has found how deep these 
cocoons lie, it is easy to have the surface-soil removed to just below 
that depth, and by removing this and destroying it, with the cocoons within 
it, the infestation may be fairly carried out of the place ; but care must 
be given that the cocoons are destroyed, or otherwise the Sawflies that 
hatch out of them will fly back to the trees and begin the attack over 
again. 
It might probably save a deal of trouble, in the case of espaliers or 
wall-trees, when the flies are seen to be infesting them, to run a length 
of tarred cloth or paper beneath the boughs, and shake them well 
morning or evening. The flies are stated to fall and to remain 
motionless for a short time ; this would allow of them being stuck fast to 
the tarred surface which they fell on, and would save much egg-deposit. 
