Hijlory of Tipula Trltici. 105 



Several fpecies of the genus Empis alfo frequented the wheat fields, 

 often carrying off our Tipula in their diminutive beaks. 



I have now given you as complete an account of thefe infcfls as 

 the obfervations of the prefcnt year enable me. Something flill re- 

 mains to be done ; for inftance, to afcertain the male, the hyberna- 

 cula of the pupa, to colle6l further fafts relative to the two new 

 Ichneumons, and, from obfervations taken in fucceflive years, to deter- 

 mine how far our crops of this grain depend upon the increafe or 

 decreafe of the Tipula and its Ichneumons, 



Cut bono? is a query often put to naturalifts; and the agricultu- 

 rifl: perhaps will afk upon the prefent occafion, Can you inform us 

 how we may prevent or diminifh the ravages of thefe infecls r In 

 reply to this, I would obferve, that the firfl ftcp towards curing a 

 diforder, is to find out its cauie. In the prefent inftance this is the 

 bufinefs of the naturalift, and this is done. The intelligent farmer 

 has no longer to alk what occafions the mifchief ; all he has now to 

 do, is to aim at difcovering a remedy. By a fet of experiments firft 

 made upon a fmall fcalc, he may poffibly find out fome method that 

 will prevent this infeiSl from laying its eggs in his wheat : thefe 

 fliould commence as foon as the ear begins to quit the folium vagi- 

 nans or hofe ; and they ought to be continued till the germen is im- 

 pregnated, or, to ufe the rural phrafe, the wheat is off the bloflbm. 

 Perhaps fumigations of tobacco or fulphur, if mnde when the wind 

 was favourable, might render the ear difagreeable to this infe6l. 

 Much of the injury which this fly does, in years peculiarly favour-, 

 able to its increafe, it is poflible, by fome fuch means might be pre-- 

 vented ; yet it is not certain that the total annihilation of it would 

 be ultimately beneficial {h). But be it granted that our labours lead' 



the 



{h) Wc are very apt to think, tliat if certain noxious fpecies of animals could be anni- 

 hilated, it would be a great benefit to the human race ; an idea that arifes only from our 

 Vol. V. P fliort- 



