ORTHOPTERA 



137 



in wait," and may thus be called aggressive resemblance. Several species 

 from India resemble flowers, and thus attract insects, upon which they 

 feed. This is an example of alluring colors. 



The walking-sticks [Phas'mida;) (Fig. 106) afford even better examples 

 of special protective resemblance than the mantids. Our species are 

 wingless and may be either green or brown, and are usually found upon 

 twigs of a color corresponding to that of their bodies. The body, which 

 is long, straight, and slender, looks exactly like a twig, while the slender 

 legs look like so many tiny branches. One may pick up a walking-stick, 

 thinking it a twig until it moves. Although it is so repulsive to the unin- 

 itiated, it is a perfectly harmless creature. The only common species in the 

 northern states, Diapherom' era femora' la, " feeds upon the leaves of oaks 

 and other trees. It drops its hundred seed- 

 like eggs loosely and singly on the ground, 

 where they lie through the winter, hatching 

 irregularly through the following summer,"' 

 or even the second summer. Over six hun- 

 dred species of this family are known. They 

 are numerous in the tropical and sub-tropical 

 countries and present many striking resem- 

 blances to their environment, one of the most 

 perfect of which is the " green-leaf insect " 

 (Fig. 90, p. 117). Its wings, flat body, ex- 

 panded legs, and even head and prothorax 

 are bright green flecked with yellow, making 

 it look wonderfully like a leaf attacked by 

 fungi. 



" The locusts or short-horned grasshoppers 

 (Acrid'idoe) include those ' grasshoppers ' in 

 which the antennae are shorter than the body, 

 and in which the ovipositor of the female is 

 short and made up of four separate plates. "^ 

 The tarsi have three joints. The first ab- 

 dominal segment has a tympanic membrane 

 on each side. It is to this family that the 

 locusts mentioned in the Bible and in his- 

 tory belong, as well as those which have 

 wrought such havoc in our own country. 

 A conspicuous species is the common red- 

 legged locust, Melan'oplus fe'mur-ru'brum. 

 There are about five hundred species of this 

 family in the United States, but only three or 

 four of them are migratory. These go in swarms, sometimes so dense 

 as to obscure the sun as a great cloud, and when they alight they literally 

 devour every green thing in that region. The largest, most injurious, and 

 most numerous of these are the Rocky Mountain locusts (Melan'oplus 

 spre'ius). Their permanent breeding-grounds are upon the western pla- 

 teaus, from 2000 to 10,000 feet above sea level, and they cannot endure 

 for successive generations the low, moist land of the Mississippi Valley. 

 " These locusts show a tendency to become gregarious from the beginning 

 of their life as nymphs. A recent method of fighting them is to cultivate 



' Kellogg. 

 2 Comstock. 



t' 



Fig. 107. — Carolina lo- 

 cust killed by a fungus. 

 (Bulletin No. 81, New 

 Hampshire Experiment 

 Station Insect Record, 

 1900.) 



