148 INDIRECT INJURIES CAUSED BY INSECTS. 



in marshy lands, and at others not less so to corn. Reaumur 

 informs us, that in Poitou, in certain years, the grass of whole 

 districts has been so destroyed by it, as not to produce the 

 food necessary for the sustenance of the cattle.^ In many 

 parts of England, in Holderness particularly, it cuts off a 

 large proportion of the wheat crops, especially if sown upon 

 clover-lays.^ Reaumur concludes from the observations he 

 made that it lives solely upon earth, and consequently that 

 the injury which it occasions, arises from its loosening the 

 roots of corn and grass by burrowing amongst them : but my 

 friend Mr. Stickney, the intelligent author of a treatise upon 

 this insect, is inclined to think from his experiments that it 

 feeds on the roots themselves. However this may be, the 

 evil produced is evident ; and it appears too from the ob- 

 servations of the gentleman last mentioned, that this animal 

 is not killed by lime applied in much larger doses than 

 usual.'^ 



Our national beverage ale, so valuable and heartening to 

 the lower orders, and so infinitely preferable to ardent spirits, 

 is indebted to another vegetable, the hop, for its agreeable 

 conservative bitter. This plant, so precious, has numerous 

 enemies in the Lilliputian world to which I am introducing 

 you. Its roots are subject to the attack of the caterpillar of 

 a singular species of moth {Hepialus Humuli), known to 

 collectors by the name of the ghost, that sometimes does them 

 considerable injury.^ — A small beetle also {Haltica concinna) 

 is particularly destructive to the tender shoots early in the 

 year ; and upon the presence or absence of Aphides, known 

 by the name of the fly, as in the case of peas, the crop of 

 every year depends ; so that the hop-grower is wholly at the 

 mercy of insects. They are the barometer that indicates the 



^ Reaura. v. 1 1. 



^ Two species are confounded under the appellation of the grub, the larv£B 

 namely of Tipula oleracea and cornicina, which last is very injurious, though not 

 equal with the first. In the rich district of Sunk Island in Holderness, in the 

 spring of 1813, hundreds of acres of pasture were entirely destroyed by them, 

 being rendered as completely brown as if they had suffered a three months' 

 drought, and destitute of all vegetation except that of a few thistles. A square 

 foot of the dead turf being dug up, 210 grubs were counted in it ! and, what 

 furnishes a striking proof of the prolific powers of these insects, the next year it 

 was difficult to find a single one. 



3 Stickney's Observations on the Grub. 



4 De Geer, i. 487. 



