23 



The Frit Fly. (Oscinisfrit*) 



(PLATE III.) 



Though this fly has been known in this country for many 

 years, it had not caused much injury until 1888, or, at least 

 serious injury had not been traced to it. Curtis describes it in 

 " Farm Insects," evidently, under the name Oscinis vasfator, and 

 as injuring wheat plants. He does not speak of it as attacking 

 oat plants. In 1888 the Frit Fly was most destructive to oat 

 plants in many parts of England, and since then it has been 

 more or less troublesome. This year, very great harm has 

 been done to the oat crop by its action, which was materially 

 helped by the weather. During the last few years it has not been 

 noticed to have injured wheat or barley plants in this country, 

 though Schiner says it attacks barley plants, and gives Musca 

 hordei as one of its synonyms, f In Sweden also it is most 

 destructive to barley, and chiefly, as it appears, from the larvae 

 living upon the grains of barley before they harden. 



The spring of 1892 was very backward, and where farmers 

 missed the few opportunities of getting in oats that were afforded 

 them in February and the first part of March, this crop was sown 

 unusually late. Indeed, many of the oats were " cuckoo " oats, and 

 as is well known to practical men, late sown oats never grow 

 away rapidly, but linger, and are apt to " die away in May." 

 This gave opportunities to the larvae of the Frit FJy to feed 

 fully upon the soft part of the plant, in the bulb or crown, just 

 above the ground, and the insects increased and multiplied 

 enormously, and followed the plants throughout their stages. 

 Larvae were found in the bulbs, then in the nascent ears, and 

 lastly on the grains themselves. Some large fields of oats were 

 closely watched throughout the spring and summer, and this 

 progress of the mischief was clearly traced. By many the 

 sickly appearance of the oat plants and their slow growth were 

 attributed to the late sowing and the dryness of the early part 

 of the summer, whereas the larvae were really the cause. In 

 most instances there was no suspicion of the real origin of 

 their unhealthy state, as the larvas are so minute that they 

 would not be noticed by unobservant persons. 



Many of the plants attacked by this insect did not form any 

 panicles, but were stunted and abortive, and for the most part 

 exactly like the plant shown at d., Plate III. Upon examination 

 it was seen that the bulb, or centre, had been riddled by the 

 larvae. A proportion formed grain, but the panicles remained 

 enveloped in the sheaths, the plants not having strength, 

 apparently, to force them out. Traces of the action of the larvae 

 were noticed all up the stems, and pupae were found among the 

 panicles still in their sheaths. In many cases where the plants 



* It is so named because " frit " is used in Sweden, -where the fly is very 

 destructive, to designate thin " tail " corn. 



f Fauna Au.itriaca. Die Flieyen. Von. J. Rudolph Schiner. 



