INDIRECT INJURIES CAUSED BY INSECTS. 153 



this excellent esculent, especially in one parish, that a collec- 

 tion was made throughout the island for the relief of the poor, 

 whose principal food it forms. 



The chief dependence of our farmers for the sustenance of 

 their cattle in the winter is another most valuable root, the 

 turnip, the introduction of which into our system of agriculture 

 has added millions to our national revenue ; and they have 

 often to lament the loss and distress occasioned by a failure 

 in this crop, of which these minor animals are the cause. On 

 its first coming up, as soon as the cotyledon leaves are un- 

 folded, a whole host of little jumping beetles, composed chiefly 

 of Haltica Nemorum, called by farmers the Jiy^ and black 

 jack, but assisted also by other species, as H. 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 agri- 

 culturist, that from this cause alone the loss sustained in the 

 turnip crops in Devonshire in 1786 was not less than 

 100,000/.-^ 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 ad- 

 vanced, and out of danger from these pigmy foes, the black 

 larvae of a saw-fly (Athalia Centifolice), called by the farmers 

 the " Mack " and " nigger " caterpillars, take their place, and oc- 

 casionally do no little mischief, whole districts being some- 

 times nearly stripped by them; so that in 1782 and 1783, 

 many thousand acres were on this accoimt ploughed up : and 

 in 1835, 1836 and 1837, the injury was not less extensive.^ 



1 The farmers would do well to change the name of this insect from turnip-fly 

 to turnip-flea, since, from its diminutive size and activity in leaping, the latter 

 name is much the most proper. The term, the fly, might with propriety be re- 

 stricted to the Hop-aphis, and other species of the same genus; and this is the 

 more desirable, because the hop is also subject to the attack of a Haltica, which 

 the hop planters are judiciously beginning to distinguish by the name of the 



2 Young's Annals of Agriculture, vii. 102. For a full history Haltica Ne- 

 morum, 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. 24.), 

 who, though no entomologist or agriculturist, has by his practical good sense and 

 habits of patient and accurate observation, thrown m.ore light on this previously 

 obscure subject than all his predecessors. 



3 Marshal in Fhilos. Trans. Ixxiii. 178S. See Trans. Ent. Soc. Lond. i. 

 proc. Ixvi., 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 



