affecting the Turnips, Corn-crops, Sfc. 
201 
has so encourajred that pest that it has been known to destroy an 
entire field of wheat. This difference probably arises from the 
effects on the roots of the grass; if the top of the turf only be 
pared off, the roots will die, whereas by going 4 inches deep they 
lie and vegetate, so that when it is afterwards all ploughed-in the 
worms find the requisite pabulum, until the corn is forward 
enough to afford the Wireworms a more agreeable substitute. 
Dickson says that the destructive attacks of insects on lays newly 
broken up " may in some measure be obviated by eating such 
lands very closely with sheep previous to their being broken up, 
as by such a method the ova of such insects may be much de- 
stroyed and their propagation prevented ; and the treading the 
crop by sheep as well as the roller may likewise be beneficial ; 
horses have also been turned in for the same purpose by some 
cultivators." * It is supposed by many that folding oxen and 
sheep upon infested fields will check the Wireworm by stopping 
their burrowing; but it seems more likely to arise from the beetles 
not being able to get out of the earth from their pupae cases, and 
those which do effect their escape, finding no appropriate place 
for the deposition of their eggs, depurt for a more suitable locality ; 
this operation might therefore be most advantageously adopted 
early in the spring before the beetles hatch. 
Mr. Bates assured me that he preserved his turnips by harrowing 
and hard-rolling the land in March and April, and that it was of 
no use later in the season. In another place, alluding to barley,' 
Mr. Dickson also saysf that if the plants suddenly change from 
a healthy green to a yellow cast "the use of the roller should be 
had recourse to, in order that the superficial parts of the soil, 
which are probably become too loose and porous, may be effec- 
tually pressed, and thereby rendered too close and compact to 
admit the worm to prey upon the tender roots of the young 
plants. That this effect may be produced in the most effectual 
manner, the roller should be of such a size, or so loaded as to 
afford a pressure equal to the draught of three or four horses, 
which should be yoked double, in order to increase the effect by 
their treading. It has been suggested that if by this method the 
injury can be counteracted until such time as rain falls, there 
need not be any apprehension for the crop, as the plants will soon 
push forward in such a manner as to become too strong to be in 
danger from this insect." J Top-dressings of lime before using the 
roller would be useful. All this is very reasonable, for by ex- 
cessive pressure the Wireworms are compelled, at least for a time, 
to descend into the earth ; and it must be beneficial in its subse- 
quent effects, for numbers of eggs may thus be destroyed, and if 
* Practical Agriculture, vol. i. p. 582. t Ibid., vol. i. p. 570. 
X Dickson's Synopsis of Husbandry, p. 91. 
