1920.] 



The Warble Fly. 



995 



From long observation of the Nightjar and its habits we 

 believe that it is very uncommon for this bird to feed during 

 the day-time, although a few instances of day-time feeding 

 are on record ; nevertheless, the amount of food it takes from 

 sunset to sunrise must be considerable. Digestion, we know, 

 is fairly rapid, but in all the 62 birds examined there was only 

 one of which the stomach was about three-quarters full ; in the 

 remaining 61 obtained between the hours of 10 p.m. and 4a.m. 

 the stomach was tightly packed with food only recently taken 

 and the remains of food previously obtained. 



In view of the very beneficial nature of this bird's work, 

 farmers would do well for the general good and their own interest 

 to use their utmost efforts to protect and preserve it. 



As far as any future legislation is concerned, the Nightjar, 

 and its eggs, should be protected during the whole of its 

 residence in this country. 



THE WARBLE FLY. 



Every farmer is familiar with the barrel-shaped maggots 

 that are often to be found in large numbers from January 

 until May just under the skin on the backs of cattle. These 

 maggots are the grubs of the warble fly. When present in 

 large numbers they are the cause of enormous loss to farmers, 

 much greater than is commonly realised. At a low estimate 

 the annual loss in damaged hides alone is put at upwards of 

 £500,000. This, however, is not the only damage they do. 

 The butcher often finds the flesh beneath the " warbled " areas 

 so altered by the inflammation set up that the beef is what 

 is known as " licked " and is useless for human food. 



Although the maggots are the chief culprits, the adult flies 

 are by no means free from blame. When flying round on the 

 lookout for a suitable place to lay their eggs they frighten the 

 cattle, which rush about the field with their tails in the air. 

 This " gadding " often causes the animals to lose condition and 

 decreases the 3deld of milk in cows. 



Kinds of Warble Flies. — ^There are two kinds of warble flies in 

 this country ; both are much Hke small bumble bees in 

 appearance and fly in bright sunshine with a '* hum " distinct 

 but not loud. The larger warble fly, known scientifically as 

 Hypoderma hovis, and generally more common, has whitish 

 hairs over the front of the body and lemon yellow hairs at the 

 tail, while the smaller kind, H. lincata, has the front region 

 largely bare of hairs and a bright orange tuft at the tail. 



3x2 



