&amp;lt;J Cultivation of Arable Land.lVheat Infefts, Definitive of. 



fcribed with fufficient correctnefs by writers on agriculture j* it is, however, 

 probable that there may be different varieties of the fame grub, that may be 

 hurtful to grain crops. One kind of grub is afiferted to be annually found in wet 

 fituations in larger or fmaller quantities, according as the preceding feafon has 

 been hot or cold : and that while it continues in the ftate of egg it cannot be 

 injured by any feverity of weather that may occur. Even in the grub flate it is 

 not capable of being much injured; and when in that of the fly it is equally 

 hardy. The only period in which it appears to be fufceptiblc of injury, is that 

 of its tranfmutation from the grub to the aurelia ftate, in which ftage it is ca 

 pable of being deftroyed by cold and wetnefs ; and aa this change moftly takes 

 place fome time about the end of May, or in the early part of June, at which 

 times rain generally falls in abundance, the whole, except fuch as have fecured 

 themfelves in dry hills of mould, in meadows, or the borders of ditches, are an 

 nually killed. On arable lands few or none are believed to efcape to effect the 

 purpofe of propagating their kind, unlefs in fuch feafons as are unufually 

 droughty during the time of their change into the aurelia ftate.f Hence the 

 rains that fall at fuch periods are not only beneficial in promoting the crop, but 

 in deftroying this fort of infect. 



Befides this, it is obferved in the fame work that there are feveral other grubs 

 brought forth at all feafons in dry lands, which are not lefs injurious to corn 

 crops than that juft defcribed. They equally polfefs the power of refilling the 

 hurtful effects of the weather in every, ftage but that in which they are changed 

 into the aurelia ftate, when moifture and cold have the power of readily deftroy 

 ing them. The whole of the grubs that are produced on foils of the more dry 

 kind are faid to be of the moth tribe. 



It is added, that the grub, when the autumn has been mild and warm, is 

 brought into exiftence about the latter end of October, and proceeds in its 

 growth as long as vegetation continues in any degree ; after which, probably 

 from the want of food, it feems to remain at a ftand till the fpring feafon, when 

 its ravages foon become evident. It begins to increafe in fize towards the end 

 of February, and continues to grow till the early part of May, when it is often 

 more than an inch in length, and one third of an inch or more in circumfe- 



* It has been fuggefted by the author of a paper in the twenty-fifth volume of the Annals oij 

 Agriculture as belonging to the genus tipula. 



t Farmer s Magazine, vol. IJ, p. 365. 



