NEMATOCERA. 77 



on other grasses, and that broods from these infest the wheat : the 

 reference above is certainly in favour of this theory. The "Wheat 

 Midge " is attacked by Flaiygaster tipulce, which lays eggs within its 

 eggs by means of a very long ovipositor, and by Macroglenes pene- 

 trans, which lays eggs within the larvs. This insect was first 

 recorded in England in 1776, then in North America, then in France, 

 and later in x^ustria, Hungary, Germany and Prussia. 



Prevefttioti and Remedies of Attack : 



Miss Ormerod says (in the work mentioned before) : " The best 

 method for prevention of this ' Red Maggot ' is to give it no winter 

 shelter, which is naturally at the roots of the corn crops or of couch 

 grasses, and artificially in large chaff-heaps. The chaff-heaps and the 

 rubbish and dust from the threshing machine can be easily managed, 

 and in the fields a great deal of the ' Red Maggot ' may be got rid 

 of by special methods of ploughing, or by taking the cultivator 

 through the land and collecting and burning the stubble roots." 



In America various methods of ploughing in the stubble and top 

 soil, and thus placing the " Red Maggot " under unfavourable condi- 

 tions, are employed. But one of the most important points in pre- 

 venting the spread of this pest is entirely doing away with those hot- 

 houses of "Wheat Midge," namely, heaps of chaff and dust from the 

 threshing machine, which are so often seen. Not only does this 

 mode of heaping the chaff seem to hasten and favour development 

 of the Midge, but it enables the breeding to take place more freely, 

 for we know that very few (J's are found in the cornfields, and Miss 

 Ormerod, from her observations, thinks that the pairing takes place 

 amongst the countless number seen over these heaps ; if, then, tlitse 

 were burnt or placed in unfavourable conditions, such as in cattle 

 yards, much good might be done by not only retarding development 

 of the " Red Maggot," but by stopping the further production of the 

 species. 



Dr. Taschenberg recommends the destruction of couch grass near 

 cornfields, as it harbours this fly to a large extent, and he further 

 says: "The meadow foxtail grass is certainly at present open to 

 suspicion of infestation."* Griffithst says destroy especially the \>ild 

 oat grass {Avenafatua), upon which the larvae of the wheat fly feed. 



D. Erax/nella, Mea.de.) a, nn, , , Ta ^ ^„ 



' ;- The Ash-cauliflower Gnat. 



= C. Jl/i/iiita, Wtz. i 



Dr. Meade says this is probably the same as C. minufa, of "Win- 



nertz. It seems to be intermediate between Diplosis and Cecidoni '. ia. 



* Practische Insectenkunde, pt. iv., p. i6 ; also vide American Gov. Repo.15. 

 t Diseases of Crops, chap, iv., p. 117. 



