Tlie Diamond-hack Moth. 
627 
" No, we cannot find it, but charlock is not abundant in this 
district."— R. C, for Lord Auckland. 
" Charlock affected."— G. D. 
" I have noticed charlock, but could never find any caterpillar 
on it."— J. P. D. 
" Having no charlock, cannot say." — J. D. 
" A caterpillar is said to have attacked charlock, of which there 
are great quantities in some fields near here, but I cannot say which 
variety."— W. F. 
" In regard to ' charlock,' I infer by this you refer to what we 
in this country side (and indeed generally in Scotland) denominate 
ranches, otherwise ' wUd mustard,' and in some parts ' skellicks.' 
The insect feeds as greedily on it as on the turnip." — J . G. 
" This is undoubtedly the same caterpillar that frequents char- 
lock. I have carefully examined it with the naked eye, and also 
with the magnifying glass." — J. H. 
" The caterpillar seems to eat the charlock much in the same 
way as the turnip, neither more nor less." — J. L. 
" Charlock not grown here much." — " N. Lines." 
" Charlock and turnips suffered equally, mangel not at all ; in 
Bome fields have never known them on charlock before, and we 
have plenty." — R. C. R. 
"Scarcely any charlock on farm ; couch the chief weed." — J. Sn. 
" There certainly is a considerable amount of wild mustard 
about our land. I did not notice the caterpillar on it, but cannot 
say I looked carefully." — J. B. S. 
"There is charlock (yellow weed, wild mustard) in Islay, but 
you may drive a summer's day and not see a specimen, so that plant, 
I may sav, has nothing to do with appearance of the grub. ' — 
R. S. S. 
"No charlock in this neighbourhood." — R. W. S. 
" Have no experience of charlock." — G. T. 
"In an early-sown field, where turnips (swedes) and charlock 
came together, both seemed to suffer equally. 
" In part of a late-sown field with only a little charlock in it, 
wliere, owing to continued dry weather, the charlock came before 
the turnips (yellow), the former was much more severely attacked 
than the latter."— D. W. 
"Affects charlock about the same as turnips." — F. W. 
ScMM^uiY. — The above observations prove that the diamond-back 
caterpillars frequent charlock as a regular food-plant, although this 
plant is by no means always mentioned in lists of the plants especially 
liable to this infestation. 
7. Kinds of birds especially useful in clearing the caterpillars. 
"Cannot say that I observed any birds actually at work devour- 
ing the larva;." — E. A. A. 
" Have no doubt but that the starling and the sparrow have 
assistetl largely in mitigating the evil. Possibly the rook may 
