SOME INSECTS OF ECONOMIC IMPORTANCE. 311 



(c) Warble flies. These deposit their eggs on the 

 cattle. The maggots also are licked into the mouth 

 and pass to the gullet. They do not, however, pass direct 

 to the stomach, but bore through the gullet walls, migrat- 

 ing throughout the body. They eventually arrive at the 

 tissue just under the skin in the neighbourhood of the back- 

 bone. They thus live within the ox for about ten months, 

 when they find their way to the outside through the skin. 

 The larva falls on the ground, pupates, and in a few weeks 

 becomes an adult. The hides are thus injured by the exit 

 of the fly and are known as " warbled hides." The losses 

 entailed through the activities of this fly are very consider- 

 able. 



3. Flies attacking Crops, etc. 



There is a long list of these, the most important of 

 which is undoubtedly the Crane fly or " Daddy-long-legs." 

 Its life-history is outlined below. 



The Crane Fly or Daddy-long-legs. 



There is more than one species of fly of this type to be 

 met with, but the habits of the two commonest are very 

 similar. They may be seen on the wing from May to 

 September, one species appearing early and the other later. 

 A specimen should be caught and examined. 



It will be found to be a true fly, i.e. it has one pair of 

 wings only. Behind these there is a pair of slender, 

 knobbed, rod-like bodies. These take the place of the 

 wings occurring here in most other insects, and are known 

 as " halteres " or balancers. Other structures worth noting 

 are the large greenish compound eyes and slender feelers 

 on the head, and the three pairs of long " spidery " like 

 legs. Two kinds of insect will be noticed. In one the tip 

 of the hind body tapers to a fine point. This is the female 

 insect. In the male, which is smaller, the tip is blunt and 

 appears slightly upturned. 



These insects may be seen flying about pastures or by 

 roadsides where long grasses abound. Sometimes they 



