affecting the Pea- crops, Mangolcl-wiirzel^ and Beet. 405 



mountain-ash; it seems therefore probable that it will live upon 

 caterpillars ; and Dr. Calvert, some years since, sent me spe- 

 cimens he had found in his wheat-fields in Yorkshire, ^vhicli 

 he suspected injured the corn. The most remarkable trait in 

 the economy of this insect is, that its larva will feed upon the 

 leaves of the mangold-wurzel, for it had always been considered 

 to live, like its parent the beetle, upon putrid animal substances, 

 Mr. Haliday, however, has found a few larvae of a Silpha at the 

 roots of artichokes in Ireland, and they are also abundant under 

 marine rejectamenta there ; it is therefore possible that they feed 

 upon sea- weeds and any succulent or gelatinous vegetables 

 which approach animal substances in texture and fleshiness : but 

 here again, if such be the case, is a considerable difference in 

 the habits of the insects ; because the larvae hitherto known, only 

 live upon putrid animals, such as dead birds, rabbits, hares, 

 hedgehogs, &c., whereas those I am about to describe feed upon 

 theyr^^A- expanding leaves of the mangold-wurzel. 



In June, 1844, my attention was first called to this subject by 

 W. Ogilby, Esq., who sent me specimens of the larvae, for- 

 warded to him by the Rev. Edward Bowen ; and he informed 

 me that they had eaten off all the mangold-wurzel on the farm 

 of John Ferguson, Esq., of Castle Forward, Londonderry. 

 Nothing further occurred until I received a communication from 

 the Rev. C. Maxwell, of Birdstown, Londonderry, dated 31st 

 May, 1846, with one of the larvae, and stating that his mangold- 

 wurzel was being devoured by this animal; and, on June the 9th, 

 he added that every plant had been annihilated. The field had 

 been entirely dressed with common farm-yard manure : on the 

 23rd of April, about half a rood of carrots and the same of 

 parsnips were sown ; next in order an acre of mangold-wurzel, 

 then Swedish turnips ; and, on the 1st of May, beet- root. 

 Every crop promised to succeed, except the mangold-wurzel, 

 which was destroyed by the larvae alluded to. They were 

 to be seen in large quantities in the mangold-wurzel ground, but 

 none in that portion of the field under other crops. Subse- 

 quently, however, the beet-root was assailed by the same insects : 

 it seems the crop was attacked almost as soon as it appeared 

 above ground, viz., about the 21st of May, and the larvae dis- 

 appeared at Midsummer, for only two could be found on the 

 24di of June; they were then in the pupa state, or might be 

 starved for want of food. It is the leaves they devour, leaving 

 only the fibres. In 1847, Mr. Maxwell says, in a letter dated 

 June the 12th, " This destructive animal has again visited the 

 same crop this season, at the same time of the year, and under 

 similar circumstances; but in greater numbers and with in- 

 creased injury to the crop. The specimens transmitted are 



VOL. VIII. 2 E 



