INSECTA 79 



THE RED-LEGGED LOCUST, OR GRASSHOPPER 

 Melanopus femur-rubrum DeGeer 



Self -maintenance. The grasshopper eats grass or almost 

 any other vegetation. Its food is, therefore, abundant 

 and easily found. If hungry, it gives a few hops this way 

 and that, and finally lands in the midst of plenty. Once 

 established on a blade of grass, its jaws start swinging side- 

 ways, and it chews away until satisfied. The strong 

 mandibles, or jaws, bite off the grass. The other mouth 

 parts help manipulate the food and pass it on into the 

 esophagus, much as the lips and tongue help the teeth in 

 handling our food. 



The grasshopper is well provided with sense organs 

 which may help it in finding and testing its food (Fig. 41). 

 The antennae are supplied with tactile bristles for feeling 

 and olfactory pits for smelling. The sense of touch is 

 very acute but smell is less developed than in insects like 

 flies, which find their food by its odor. In addition to the 

 olfactory pits of the antennae, others occur on the body 

 between the bases of the legs. On some of the mouth 

 parts there are gustatory pits. These are organs of taste 

 which test the palatability of the food before it enters the 

 mouth. 



There are five eyes on the head. The front bears three 

 simple eyes, or ocelli ; two near the bases of the antennae and 

 one near the center of the forehead. At the sides of the 

 head are the great oval compound eyes, made up of 

 thousands of six-sided ommatidia. Each ommatidium is 

 a complete organ of vision, with a lens, pigment, a sensitive 

 nerve ending, and nerve fiber connecting with the optic 

 ganglion and the brain. A compound eye may see either 

 a mosaic or an apposition image. In the first type there 

 is a picture of the surroundings but it is broken up into a 

 great number of small pieces, each of which is perceived by 

 one ommatidium. In an apposition image the view in 

 each ommatidium overlaps those adjacent to it so that 



