How insects move 



Fig. 57. A sawfly. Order Hymenoptera-Symphyta. Note the network of 

 large cells in the wing, and the absence of a 'waist' to the abdomen 



lence. If you watch a patch of brilliant sunlight, either in a wood, where 

 shafts of light fall across a dark background, or towards evening, when 

 the rays are more horizontal, you can see the spots of Ught ghnting from 

 these insects as they are carried to and fro in the air. They obviously 

 have little power of controlled flight compared with, say, a wasp or a 

 bee. 



It is mostly these insects that are carried up in the air to great heights, 

 and from one continent to another, across oceans and deserts. Now 

 and then good fliers, such as hoverflies, have ahghted on ships far out 

 to sea and have obviously been carried away by the wind from their 

 usual haunts, and have gone on flying mechanically until they found 

 somewhere to alight. Quite large butterflies and other insects take part 

 in mass migrations, as we shall see in the next chapter. But by and large, 

 the inseas that are carried helplessly from one country to another are 

 the small and the weak fliers, and it is from these that much of the 

 insect population of remote areas has been derived. 



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