The Biarnond'hack Moth. 
591 
diately followed. Further information was, however, desirable as to 
whether the subsequent damage and consequent money loss from 
the attack had been to the extent apprehended, and also as to what 
remedies had been tried, what was their success, and generally 
any information bearing serviceably on the matter from ob- 
servers acquainted with the infestation, so as to be able to distin- 
guish it trustworthily from that of turnip sawfly or other attacks 
to turnip leafage. 
With this object I at once arranged a short circular requesting 
information on the following points 
1. Any estimate of amount of loss, whether in acreage, mileage, or money 
loss on crop. 
2. Any measure found to amice}- in lessening amount of ravage, or loss 
from its effects; as, for instance, effect of fertiUsers, as nitrate of soda, 
superphosphate, soot, lime, &c., given as dressings to push on crop ; or any 
dry or fluid dressings applied to the leaves to clear the grubs, and how 
Fig. 1. — Plutella cnucIFF.UAIa•^r. 
1, Caterpillar ; 2, eggs ; 3, diamond-back moth (all natural size) ; 4, 5, diaruoud-back moth, 
at rest and tij ing (magnified).' 
applied, as by strawsonizer, knapsack sprayer, &c. ; also effects of any 
mechanical measxu'es, as taking horse-hoes, or scufflers with houghs on them, 
through the crops ; or use of " sbeep-diiving." 
3. Opinion asked as to benefit of heavy rains. 
4. Nature of land — also how cultivated (especially whether autumn 
cultivated and whether ploughed deeply) — what manure was used, and was 
salt used ? 
5. Was weather observably wet or dry in previous autumn, so as to 
cause difficulty in cleaning the land, and was any particular weed unusually 
noticeable ? 
fi. Is this caterpillar found to e^'pecia.Yly frequent charlock? 
7. What hinds (f birds are especially useful in clearing the caterpillars ? 
This circular I forwarded to my correspondents, requesting to be 
favoured with replies, and in the following pages I have embodied 
(with due acknowledgment to the contributors) tlie chief points of 
the information sent me regarding this year's attack, and also of 
the information previously in my hands. 
This I have divided in the following pages under three headings. 
' This figure is inserted by permission of Messrs. Blackie & Son, Glasgow, 
