76 On the Means of preventing 



in the fields " where the wheat grew*" Under a proper system, 

 therefore, the race might in a great measure be extirpated in any par- 

 ticular district. It is absolutely necessary however, that there should 

 be a general combination for that purpose. Nothing done in the field 

 where the new wheat is sown, can be of any use, for the fly is pro- 

 duced in fields, not under wheat at the time, and flies about, until it 

 finds a plant suitable for its purpose. 



In seasons, when the frost may not be supposed sufficiently violent, 

 the desirable object may be obtained, by frequently stirring the ground, 

 and by rolling and treading it, or burning stubble upon the surface, or 

 by the use of hot-lime. Fumigations of tobacco or sulphur, made 

 when the wind is favourable, might also render the ear disagreeable 

 to this insect f. 



If other means are ineffectual, surrounding the field of wheat with 

 a belt of hemp, the smell of which is so peculiarly noxious to insects, 

 might be tried J. The smoke of burnt weeds, and in particular of 

 sea weeds, might also be of use. 



In the course of these inquiries, I have seen very strong assertions 

 made of the beneficial eflfects of elder, in protecting growing plants 

 from the attacks of insects ; in proof of which it is said, that when a 

 whole district was infested with cockchafers, and scarcely a green 

 leaf was untouched, the elder alone remained uninjured . This plant 

 is said, 1 . To preserve cabbages from being injured by caterpillars ; 



2. To prevent blights and other effects on fruit and other trees || ; 



3. To protect crops of wheat from destructive insects ; and, 4. To 

 prevent the destruction of turnips by the fly, if elder bushes are drawn, 

 for that purpose, along turnip drills. 



It is recommended, to beat the cabbages with twigs of elder, or to 

 make a strong infusion of elder water, and sprinkle it over the plants 

 with a watering pot. 



It has been remarked, that the greatest mischief is usually done to 



* Mr Sheriff has ascertained, that embryos are likewise deposited in the triti- 

 cum repens, or couch grass, which delights to grow in hedges, and other neglect- 

 ed situations ; but these could easily be extirpated. 



j- Trans, of the Linnagan Society, vol. v. p. 105. 



j: It may be proper here to mention a curious fact recorded in the Sur- 

 vey of the Hebrides. A cottager there, had bis cabbages much injured by the 

 caterpillar. He surrounded his little garden ivitli fiemp, and was no more mo- 

 lested by them, the smell of that plant being noxious to insects. The same idea 

 exists in France, as appears from the following paragraph : 



" Quelques personnes ont cru reconnaitre, qu'en semant du chanvre sur toutes 

 " les bordures d'un terrain, les chenilles n'ont point depasse cette barriere, 

 " quoiqu'elles infestassent tout le voisinage." Code of Agriculture, 4th edit, 

 p. 523, note. 



The dwarf elder (Sambucus ebulusj ought to be preferred, as its emits the 

 more offensive effluvia. It is rather a scarce plant, but is found in consider- 

 able quantities on the banks of the Almond near Mill-Haugh, in Perthshire. 

 The plant called Pokeweed, f P/iytolacca virginicaj, and henbane, (Hyoscyamus 

 nigerj, possess qualities so noxious to insects, that they might likewise be ustd 

 with some prospect of success. 



y The elder should be planted so as to entwine its branches among the fruit 

 trees. 



