THE BRITISH NATURALIST. 



183 



of the rubbish from the machine is deposited in heaps in the yards and 

 fields, where the flies hatch next year, and so the attack is continued. 

 It is therefore most important that all infested screenings should be 

 burnt and so effectually destroy this pest. The light grain, that also 

 may contain many puparia, should be boiled and given to stock, the 

 puparia being thus killed, which they are not by passing through an 

 animal's alimentary canal. Many " flax-seeds " were found in the early 

 threshings in South Devon, and these with the accompanying Wheat 

 Midge puparia are left, I find, as elsewhere, in heaps to decay. 



A large number of " flax-seeds " are also left in the stubble or gratten, 

 either on the straws when cut high or fallen out on to the ground. This 

 I particularly noticed last year in barley fields near Teignmouth. It is 

 also important, then, to destroy these by some inexpensive methods. 

 Burning the infested stubble or ploughing it in deeply wiil be found to 

 do this. In burning the stubble care should be taken to start the fire 

 all round the edges of the field, so that the fire burns to the centre. In 

 deep ploughing the kind of plough required is one fitted with a skim- 

 coulter, the skimming thrown into the preceding furrow and so buried. 

 Clean farming will also tend to keep down the pest, especially by 

 destroying that pernicious weed, "couch" grass or "twitch," for the 

 Hessian Fly lives also upon this grass as well as upon Timothy Grass. 

 Near Teignmouth, Torquay, and Exmouth I found in the Autumn 

 many puparia upon " couch " grass, as well as in the stubble. The 

 kinds of corn attacked are wheat, barley, and rye. So far there are no 

 records of oats being destroyed. I do not think it has been recorded 

 in rye in South Devon, and I have not myself observed it. The stiff- 

 strawed varieties withstand attack better than the thin, and where the 

 fly has appeared, if possible the former should be chosen. It is also 

 desirable that Autumn-sown wheat should be put in as late as possible, 

 so that the second brood of the fly will have died off before the plant is 

 up. One cannot well account for its great increase last year in South 

 Devon. Although no doubt it has been present there for some years, 

 it would surely have been noticed before had it been in such numbers. 

 I observed it in a large number of places in the southern part of the 

 county, especially where the ground was not " done " well, and I saw 

 in the Sta?tdard that Mr. Enock also noticed its abundance in the same 

 1 district. I expect if this fly were searched for, it would be met with in 

 Cornwall and other parts of Devon, in fact inmost parts of England. I 

 suppose its numerous and constant records from the East of England 

 are due to the quantity of that " valueless " crop, wheat, grown in that 

 part. 



Correction. — On page 137, in line 10 from top, read erucifovnus for cruciformis, 

 and also for description of woodcut, Fig. 1, same page. 



