f 
104 INDIRECT INJURIES CAUSED BY INSECTS. 
as IT, concinna, attack and devour them; so that, on account of their 
ravages, the land is often obliged to be resown, and frequently with no 
better success. It has been calculated by an eminent agriculturist, that 
from this cause alone the loss sustained in the turnip crops in Devonshire, 
in 1786, was not less than 100,000/.1 Much damage is also sometimes 
occasioned by a little weevil (Nedyus contractus), which in the same 
manner pierces a hole in the cuticle. When the plant is more advanced, 
and out of danger from these pigmy foes, the black larvae of a saw-fly 
(Athalia Centifoliz), called by the farmers the “ dlack” and “nigger” cater- 
pillars, take their place, and occasionally do no little mischief, whole 
districts being sometimes nearly stripped by them; so that in 1782 and 
1783, many thousand acres were on this account plonghed up: and in 
1835, 1836, and 1837, the injury was not less extensive.? The caterpillar 
of the cabbage-butterfly (Pontia Brassica), is also sometimes found upon 
the turnip in great numbers; and Sir Joseph Banks informs me that forty 
or fifty of the insects before mentioned, called by Mr. Walford the wire- 
worm, but more probably, as there observed, the larvae of one of the tribe 
of Brachyptera or rove-beetles, have been discovered in October just below 
the leaves in a single bulb of this plant.—The small knob or tubercle often 
obseryable on these roots is inhabited by a grub, which resembles one found 
in similar knobs on the roots of Sinapis arvensis (from which I have bred 
Nedyus contractus, and N. assimilis, small weevils nearly related to each. 
other), and like it produces a small weevil, Ceutorhynchus sulcicollis. This, 
however, does not seem to affect their growth. Great mischief is occa- 
sionally done to the young pase by the wire-worm. I was shown a field 
last summer in which they had destroyed one fourth of the crop, and the 
gentleman who showed them to me calculated that his loss by them would 
be 100/. One year he sowed a field thrice with turnips, which were twice 
wholly, and the third time in great part, cut off by this insect.8 The roots 
are also sometimes seriously injured by the caterpillars of the moth 
(Agrotis Segetum) before mentioned as destructive to wheat crops on the 
Continent. Whether the disease to which turnips are subject in some 
parts of the kingdom, from the form of the excrescences into which the 
1 Young’s Annals of Agriculture, vii. 102. Tor a full history of Haltica Nemorum, 
from the egg to its perfect state, see the very valuable paper of Henry Le Keux, 
Esq., in the Transactions of the Entomological Society of London (ii. ar who, 
though no entomologist or agriculturist, has by his practical good sense and habits 
of patient and accurate observation, thrown more light on this previously obscure 
subject than all his predecessors. 
2 Marshal in Philos, Trans, Ixxiii. 1783, See Trans. Ent. Soc. Lond. i. proc. 1xvi., 
ii. proc. Ixxviii. and the admirable Prize Essay, containing a full history of this 
insect by G. Newport, Esq., 1838, See also the valuable papers on this insect, and 
on the turnip-flea, in Journal of the Royal Agricultural Society of England, vol. ii., by 
John Curtis, Esq. 
5 Trans, Soc. Ent. Lond. ii. proc. xxx. A striking instance of the use of hand- 
picking (in most cases by fur the most effective mode of getting rid of insects) ap- 
peared in the West Briton, a provincial paper, in November, 1838, stating that Mr. 
G, Pearce of Pennare Goran had saved an acre and a half of turnips, sown to replace 
Wheat destroyed by the wire-worm and attacked by hosts of these larve, by setting 
boys to collect them, who, at the rate of three half-pence per 100, gathered 18,000, 
as many as 50 having been taken from one turnip, Thus at an expense of only 
Il. 2s, 6d. an acre and a half of turnips, worth from 52 to 7/, or more, was saved; 
while as the boys could each collect 600 per day, 80 days’ employment was given 
to them at 9d. per day, which they would not ai evens have had. 
