244 INSECT ORDERS 



ably from the other two in appearance. They are small and slender and 

 a pale green color. As their name indicates, they live in trees and start 

 their shrill song at dusk, continuing it far into the night. 



4. Roaches. These insects have flattened bodies which enable them 

 to crawl through small cracks. They prefer to run rather than fly, but 

 have functional wings and will fly sometimes when cornered. They 

 usually come out to feed during the night and hide during the day so 

 that a house can be badly infested without the knowledge of its owner. 



Photo by Winchester 



Fig. 17.3. Ventral view of the large German cockroach. Note the flattened body and 



the powerful running legs. 



5. The mantids. These are commonly called praying mantids or 

 devil-horses. They are large carnivorous insects that are very bene- 

 ficial because of the great number of harmful insects which they eat. 

 The praying mantis gets its name from the fact that it holds its front 

 legs up in an attitude of prayer, but the name "preying mantis" would be 

 more appropriate since it is probably just waiting for some insect to get 

 within reach so that it can grab it with these legs. 



6. The walking sticks. These have long stick-like bodies that are 

 remarkably like twigs upon which they rest. They do some damage by 

 eating leaves, but usually are not present in sufficient numbers to be 

 serious. 



