278 



The Frit Fly. 



[June, 



The Frit Fly is a serious menace to cereal crops throughout 

 the whole of the Northern and Central Europe and the British 

 The Frit Flv' England the severity of the 



A -rfc attack varies from year to year. In bad 



A Danger to xi i i / x 



-n ^-,1 years the whole oi the country, except 



Cereal Crops. t^. ^ . . , 



perhaps the Fen Districts, is seriously 



affected; in other years local damage may occur anywhere. 

 The greatest damage is done to spring-sown oats, but winter 

 oats, winter and spring-sown wheat, barley and rye hava 

 been attacked and possibly have suffered more injury than is 

 usually recognised. 



The damage to spring-sown oats becomes apparent in late 

 spring and early summer. The main shoot and possibly the 

 first formed tillers cease to grow, the young central shoot dies, 

 but the outer sheathing leaves may remain green. Further 

 tillers form, but perhaps too late to produce ears. A fresh 

 attack occurs in July; in this case the ears are damaged and 

 while the larvae may be found living on the young soft corn, 

 which they either destroy or so damage as to render it worth- 

 less. It is true that this attack is often overlooked, as the effect 

 on the field is not very apparent. The chief indication of the 

 damage is the very light weight of the crop on thrashing. 

 Should the grain be threshed at harvest time, the cause of the 

 light weight may become further apparent from the great 

 number of flies that will issue from the store. A crop may be 

 ruined by the first and at least badly damaged by the second 

 attack. 



Frit and eel- worm may occur together, but a frit attack is 

 c.ften confused with that of the eel-worm and recorded under 

 I hat name. Perhaps the best superficial characteristics by 

 which an eel-worm attack may be determined are the swollen 

 base of the plant and the absence of the white frit grub. 

 (Irowers, however, are advised not to rely upon their own 

 diagnosis, but to consult an expert. The researches of Pether- 

 bridge at Cambridge seem to show that the attack on v/inter 

 wheat occurs almost solely when this crop follows late 

 ploughed leys — notably of rye grass. This attack may be 

 i-, voided by bastard fallowing. 



Frit-like larvae — whether the pest of the cereal or of some 

 allied species is not clear — have been found on annual meadow 

 grass, smooth meadow grass, couch grass, perennial rye grass, 

 Italian rye grass, Timothy, meadow foxtail, wood millet, 

 meadow fescue, vellow oat grass, common oat grass, and its 



