The Grasshopper 349 



The limbs are at first limp and directed backward. The animal is still 

 enveloped in a thin veil or pellicle which has aided it in forcing its way 

 out of the ground. This covering shortly splits along the middle of the 

 back and works off behind. Within an hour the locust takes its natural 

 gray color. The foregoing account applies particularly to the Rocky 

 Mountain locust." 



The young grasshopper (like all exoskeletonous animals), though 

 able to feed immediately when its normal form has been completed, can- 

 not grow until it throws off its outer covering. This ecdysis occurs 

 periodically. Of course, it takes time for the new skeleton to harden, 

 so that, immediately after shedding its covering, the animal is rather 

 soft. The wings appear after the first molt (Fig. 227). They increase 

 in size with each molt but become functional only after the final molt. 

 An insect which at birth resembles its parent, but is not entirely like it, 

 as the young grasshopper, is called a nymph ( ). 



The last molt takes place in the late summer. The nymph then 

 "climbs up some grass stem or similar object, and, taking firm hold, 

 often with its head pointing downward, remains motionless for several 

 hours, till the skin swells over the head and thorax and finally splits 

 open along a median dorsal line. From this old skin the new head, 

 thorax, legs, wings and abdomen are slowly withdrawn while soft, ex- 

 panding and hardening within half to three-quarters of an hour." 



It is then a full-fledged adult and is called imago. After the eggs 

 have been laid in the fall, most of the locusts die. 



BEHAVIOR 



As there are more different species of insects than there are of all 

 other animals combined, it is not strange that insects should be of con- 

 siderable interest and importance. 



They illustrate better than any other type of animal the interrela- 

 tionships and interdependence of all living things. 



Pollen is carried from one plant to another by insects (Fig. 239), 

 thus permitting vegetation to grow wherever there is sufficient heat 

 and moisture. This makes food more plentiful. Injurious animals and 

 pests are kept down even among their own kind. For example, the swift 

 little tachina fly (Fig. 240) pokes its egg between the segments of the 

 grasshopper's abdomen, which egg then develops into a maggot, and 

 this maggot bores its way into the interior of its host, feeding on the 

 living substance as it goes. It leaves the vital organs until last, so that 

 the grasshopper does not die until the maggot has abundantly supplied 

 itself with nourishment. Then, too, insects furnish the most abundant 

 food for birds, worms, toads, fish, and other animals. Even man has 

 not hesitated to use them as food. The Bible speaks of John in the 

 desert feeding on locusts and wild honey; one itself, the insect, the 

 other, the product of an insect. 



