DIAMOND-BACK MOTH. 
73 
evening, and lay their eggs (sometimes in great numbers) on various 
kinds of plants, and especially infest all the Cabbage tribe. 
The caterpillars are about half an inch long, and slightly tapering 
to the bead and tail, green or yellowish in colour, with grey or black 
bead, and the ring next the bead has several small black spots. These, 
when full-fed, spin cocoons of fine net-like texture on the remains of 
their food-plants, or on the ground, from which the Moth comes out 
in about three weeks or less, so that there may be a succession of 
generations during the summer. The autumn chrysalids remain 
unchanged during the winter. The caterpillars feed in heads of 
Cauliflower, and on unripe seeds of some plants of the Cabbage kind, 
as well as on leafage. 
The first specimens of these Moths were sent me on July 9th by 
Mr. Edward Riley, from Kipling Cote, Market Weighton, who men¬ 
tioned, on August 27th:—“ When we began to hoe the Turnips on 
July 9tli I was struck with the number of Moths flying about 
(hundreds of them), and was certain mischief would follow. However, 
the caterpillars did not do much harm to the early White Turnips, but 
some Rape in the same field was damaged seriously. The Rape leaves 
had white patches as large as a shilling all over the leaves, and, in the 
case of a neighbour’s Rape adjoining, the leaves were quite blanched.” 
[This white appearance was probably from the exceedingly fine web, 
like the thinnest gauze, which the Diamond-back caterpillars have 
been noticed as spinning over parts of the leaf whilst feeding (see 
Curtis’s * Farm Insects,’ p. 87).— Ed.] 
Mr. Riley further says :—“ Iliad afield of Swede Turnips attacked, 
and at once sowed nitrate of soda at the rate of 1 to 1J cwt. per acre, 
putting a small quantity on each Turnip, which in ten days had a 
marvellous effect, the Turnips growing right away from the attack. 
“ I think the reason the caterpillars have done so little damage 
among the early White Turnips is that they grew so wonderfully well 
from the first.” 
On July 30tli I received information from Mr. H. Stourton, of 
Holme Hall, York, that a great deal of damage was being done to 
Turnips by a caterpillar (of which specimens were enclosed) feeding 
on the leaves. These caterpillars proved to be of the Diamond-back, 
and nitrate of soda was about to be used to “ put some strength into 
the plant.” 
On August 8tli Mr. Stourton mentioned that he hoped not to suffer 
to any great extent, but that there were bad accounts from some farms 
in the district up to a w r eek before ; the Turnip plant had been looking 
very weak from the wet cold weather, but was then looking more 
healthy. He notes :—“ I put on nitrate of soda and soot where the 
caterpillars were numerous; we shall see the result. One of my 
