108 INDIRECT INJURIES CAUSED BY INSECTS. 



America has made us no present more extensively beneficial, compared 

 with which the mines of Potosi are worthless, than the potato. This in- 

 valuable root, which is now so universally cultivated, is often, in this 

 country, considerably injured by the two insects first mentioned as attack- 

 ing the carrot, and also by the wire-worm. The Death's-head-hawk- 

 moth (^Acherontia Atrojjos) in its larva state feeds upon its leaves, though 

 without much injury. In America it is said to suffer much from two 

 beetles (^Cantharis cinerea and vittata),of the same genus with the blister- 

 beetle^ ; and another species, C. verticalis, in 1839 wholly destroyed the 

 leaves of the crops at Volterra in Tuscany.^ In the island of Barbadoes 

 some hemipterous insect, supposed to be a Te^^ig-oma, occasionally attacks 

 them. In 1734 and 1735 vast swarms devoured almost every vegetable 

 production of that island, particularly the potato, and thus occasioned 

 such a failure of this excellent esculent, especially in one parish, that a 

 collection 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 unfolded, a whole 

 host of little jumping beetles, composed chiefly of Haltica Nemonim, 

 called by farmers the Jly^ and black jack, but assisted also by other species, 

 as H. concinna, attack and devour them ; so that, on account of their rav- 

 ages, 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/."* Much damage is also sometimes occa- 

 sioned 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-jly (Athalia 

 Centifolia) ,C2i\\&di by the farmers the " black" and " nigger" caterpillars, 

 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 ploughed 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 



» Illiger, Mag. i. 256. * Passerini, quoted in Eev. Zool. 1841, p. 354. 



3 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 restricted 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 bop planters are judiciously beginning to dis- 

 tinguish by the name of the "/ea." 



* Young's Annals of Agriculture, vii. 102. For a full history of Haltica Nemorum, from 

 the egg to its perfect stale, see the very valuable paper of Henry Le Keux, Esq., in the 

 Transactions of the Entomological Society of London {i'l. 2i.), who, though no entomologist 

 or agriculturist, has by his practical good sense and habits of patient and accurate observa- 

 tion, thrown more light on this previously obscure subject than all his predecessors. 



* Marshal in Philos. Trans. Ixxiii. 1783. See Trans. Ent. Soc. Land. 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 insect, and on the turnip-flea in 

 Journal of the Royal Agricultural Society of England, vol. ii. by John Curtis, Esq. 



