DIAMOND-BACK MOTH. 
101 
If these dressings were strewn early in the morning, or in the 
evening, when the dew is on, and consequently the dust would adhere 
to the leaves, there would be good reason to hope that they would do 
good; at least the plan would be worth a trial, as on a small quantity 
of land this could he done very thoroughly at small expense. 
Notes of useful dressings will be found in the following paper, 
which gives observations of successful applications of the above kind in 
the case of attack of Turnip Diamond-back Moth-caterpillars to Kale. 
Diamond-back Moth. Plutella crucifer arum, Zeller; Cerostoma 
xylostella, Curtis. 
Plutella cruciferarum. 
1, Caterpillar; 2, eggs; 3—5, Diamond-back Moth, nat. size and magnified. 
The caterpillars of the Diamond-back Moth are at times exceed¬ 
ingly destructive, and in 1883 and 1884 I had observations of them as 
being mischievous to leafage of White and Swede Turnip, Rape, and 
Kohl Kabi. The localities from which specimens were sent were 
chiefly various parts of Yorkshire, and near Inverurie, in Aberdeen¬ 
shire ; but notes of severe attack which appeared to be of the same 
kind were sent in 1883 as occurring in the district near King’s Lynn, 
in Norfolk, also from Watten Mains, Caithness, N.B., mentioning 
prevalence on Turnip-fields on the seaboard. In 1884, Mr. Tait, of 
Inverurie (who had himself identified the moths) wrote me in August 
that he had seen several fields in different localities all more or less 
affected, and that by report he considered the attack must be general 
over the north-eastern district of Scotland. 
From 1884, I had no further reports of the presence of the 
infestation until the autumn of 1889, when I was favoured by the 
following communication (with specimens of caterpillars accompanying) 
from Mr. Henry Ross, of Chestham Park, Henfield, Sussex. This is of 
very serviceable interest, as previously very little was known as to 
there being any good working remedy.* 
* As this attack is especially destructive to Turnips, the note stands best under 
this heading, though the special injury in the above case was to Kale. 
