280 



The Frit Fly. 



[June, 



control : a top-dressing of sulphate of ammonia does not appear 

 to be satisfactory, but nitrate of soda is said to be effective if 

 a-pplied early enough. Winter oats are seldom damaged, and 

 records show that this cereal, sown in the spring, will escape 

 infestation, possibly because it tillers more freely. In any case 

 it must be sown quite early if a crop is to be obtained. 



Experiments made to test the resistance of different varieties 

 of oats to frit fly attack, show that there are marked differences 

 but that the}^ are not the same in all parts of the country. In 

 general the more modern varieties do better than the older 

 " Abundance " types, owing to the greater speed with which 

 they throw up the central shoot. On the other hand the old 

 straw-producing oats such as Potato and Sandy, owing to their 

 powers of tillering, recover well from the first attack, though it 

 would seem that they tend to suffer more from the grain attack. 

 Probably the variety best suited to the district will in most cases 

 be found to suffer least from attack, owing to a rapid and healthy 

 growth in the young stages. In this connection the importance 

 of a good seed bed in the case of oats must not be forgotten. 

 Eough, cloddy land tends to retard growth, and in consequence 

 makes the crop very susceptible to frit fly. 



