i>4 Slnni SnninHUji of our KtioirUdtfi' of the Frit-flji 



S})!-!!!^ sowing should be avoided, when ]K).s«ible, on or near fields 

 which were attacked in the previous year. With regard to the seed, 

 early varieties, and such as are best suited to the soil and locality, 

 should be chosen. 



In 1917 ill the /'/ ,'7-inl(',stcd county of Oxfoi'dshiie it was found tiiat 

 the best time to loll the fields sown with spring oats was immediately 

 after the seed had been drilled, or at least before the young plants were 

 through the ground; oats rolled later, probably owing to the check in 

 their growth, were more severely attacked (Bland, July, 1917). 



Rorig (1893) recommended that a forage ci'oj) should not be sown 

 with oats or barley on a field that had been affected, but this advice 

 was directed to continental farmers. It would appear that grass layers 

 or newly cultivated grass or waste-land should be ploughed early in 

 the summer and bastard fallowed before planting with winter wheat 

 (Petherbridge, November, 1917). It should be remembered that on a 

 field which has been attacked and the crop harvested, the grasses and 

 young plants growing from the shelled-out corn are probably badly 

 infested ; these should therefore be ploughed up early. 



Kulagin (1913) mentioned an experiment recorded by Lindeman 

 (Russia) in which a field was sown with rye on August 10th next to a 

 badly infested crop of oats ; in the ordinary course the complete destruc- 

 tion of the rye would have been certain, but on August 13th (before 

 the rye had sprouted) the oat field was ploughed up, with a result far 

 exceeding expectations, there being no subsequent damage to the rye. 

 Fields should be kept clean of grass, and the destruction of grass borders 

 round fields, and grass edgings to field roads has been recommended. 



OBSERVATJOXS. 



This summary must not be accepted as complete, as many observa- 

 tions may have been overlooked, and the publications in wdiich some 

 are recorded have been inaccessible; also it naturally contains many 

 conflicting and probably often inaccurate statements, and impracticable 

 advice, but it should })rove of some value to those who ai'c woi'king. oi- 

 about to work, at the frit-fly problem. 



Thei'e ai'e still vei-y many })oints in the bionomics of the frit-fly 

 re(|uiring elucidation, and a very large amount of experimental work to 

 be done, before the eflicient control of this pest can be assured ; moreover, 

 reseaix'h and exiicrinicntal \\uv\< undertaken in (say) Russia caniu)t lu' 

 relied u))on as giving coi rcct data for England. The climatic conditions 

 and the ajfricultural luetliods differ so much in dilferent countries, that 



