nffccting Carrots and Parsnips. 
175 
and profitable variety in the poor man's bill of faro, in combina- 
tion with potatoes, greens, turnips, and onions. 
Carrots are already so valuable in some counties, that the 
failure of them is severely felt ; yet, with the exception of the 
turnip, I know of no crop which is more subject to the fatal attacks 
of the insect tribes in every stage of its growth. As soon as the 
tap-root is formed, until the period of its being matured, the 
maggots of a fly, as well as other little animals, including slugs, 
are constantly diminishing the produce. The young foliage no 
sooner appears than it is filled with aphides, and at a more ad- 
vanced stage the leaves become an agreeable food for caterpillars ; 
and lastly, the seed-crops are almost annihilated by smaller cater- 
pillars, which devour the flowers as well as the seeds. 
Aphis Dauci, the Carrot-leaf Plant-Louse.* 
In the first week of July last year I visited the neighbourhood 
of Guildford, in Surrey, when Mr. Ellis showed me a field of 
carrots, which had been a strong plant ; but one-tenth of the crop 
had recently gone off. This malady was indicated by the yellow 
foliage, and on pulling up the roots they were sound and clean ; 
yet the crowns were not only discoloured, but dead or dying, and 
on opening the embryo leaves we found concealed at the base 
from 2 to 7 ov 8 green aphides. A few days after, Mr. T. Dickin- 
son, of the Guildford Nursery, took me to a bed of carrots which 
was going off in a similar way. Here, however, the aphides were 
gone, excepting a female, which had been punctured by some 
parasite ; and it was evident they had commenced their operations 
earlier in the year, for the central leaves were hard and black. 
In this instance the tap-roots were becoming woody inside, and 
some of them were throwing out quantities of fibrous roots, like 
old growing carrots which had been kept through the winter. 
1. T^hese Aphides were scarcely larger than cheese-mites, of an 
uniform pale-green colour, with 6 legs, 2 horns, and no wings. 
I had hoped to have found them at a more advanced stage, when 
the females were bringing forth young, and some of them might 
have attained wings, but I did not remain at Guildford long 
enough, and I could not meet with them in Dorsetshire or in the 
Isle of Wight. 
As soon as a bed is afTected by aphides, powdered tobacco 
should be dusted over the crowns of the carrots early in the morn- 
ing whilst the dew is upon them, or they may be watered with a 
decoction of tobacco, which is fatal to all Plant-lice. Removing 
the dying plants is of little use, as the insects remove from them 
* Cuvtis's ' Guide to an Arrraigement of British Insects,' Genus 1047 b, 
No. 39. 
