NEMA TO CERA. 5 9 



down so readily as the others, and where they are healthily grown, 

 they can resist any amount of attack. 



(7) The burning of stubble is an important point in aiding the 

 destruction of these insects, and is a method that may be well 

 adapted to other diseases. It may be done by commencing the 

 firing at the borders of the field, so that the fire cannot spread out- 

 wards, but gradually gets smaller and smaller as it approaches the 

 centre. 



Dr. Packard, the American entomologist, however, is strongly of 

 opinion that this remedy would be worse than useless, as large 

 quantities of the invaluable parasites would be destroyed in the straw. 



{h) Deeply ploughing in the stubble can also be employed to great 

 advantage, as the puparia, which are usually left in the stubble, 

 cannot then develop satisfactorily. (When this is done the stubble 

 should be cut high, so that the puparia are left.) 



(s) Corn and straw that is imported should also be well examined, 

 and if the " flax seeds " are discovered, even in small quantities, 

 should be destroyed at once. 



(^) The stacking of infested straw should also be paid attention 

 to. If it is stacked square, as hay, and firmly put together, a large 

 number of the insects, even if they hatch, are unable to escape, and 

 thus are not able to advance the disease. 



{n) The destruction of all rank-growing weeds and grasses in 

 hedges around the cornfields ; for, as we have seen, the Hessian-fly 

 infests certain kinds of grass, and most probably far more than we 

 know, In this way the homes of many hundreds of flies may be 

 destroyed. 



{Q) Well-manured lands resist the attack, if a top-dressing of the 

 following is added : " Two hundredweight of nitrate of soda and one 

 and a half hundredweight of salt per acre."* Without this latter the 

 crops will suffer from the attack. 



The choice of soil for wheat and barley growing in the infested 

 districts should also be noticed. In hot and dry places the crops 

 suffer far more from the Hessian-fly attacks than in less exposed and 

 damp surfaces. I have seen fields in Cambridgeshire, in dry and 

 exposed places, badly attacked, whilst others close by have almost 

 escaped. 



There are said to be certain cures ; but, as in all other cases, " pre- 

 vention is better than cure." These cures are not satisfactory in the 

 case of this pest. One of the most important is a " dressing of gas- 



* Griffiths' " Diseases of Crops." 



