176 



NATURAL HISTORY OF ARTHROPODS. 



eastern slopes of the Rocky Mountains. This is a still smaller insect than the preced- 

 ing, is wingless and rather stout-bodied. It lives entirely on the ground, which it 

 resembles very closely in color, and is very active, running with as great rapidity as do 

 the various species of tiger-beetles that are to be met with in similar localities. 



The commonest species in Europe is the Mantis religiosa. In Buenos Ayres 

 Mantis argentina is said to seize and eat small birds. 



The PhasmidjE, popularly known as spectres, walking-leaves and walking-sticks, are 

 the most bizarre of the Orthoptei-a. They are sluggish in their movements, and are 

 found upon the twigs and leaves of plants, to which they bear a striking resemblance. 

 In fact, the species of this family are all imitative in a greater or less degree, and fur- 

 nish the strongest examples of that mimicry which is so frequent among insects, and 

 which brings them into harmony with their surroundings and enhances their protec- 

 tion. The body in most of the Phasmidfe is remarkably long and slender, and the 



wings are either aborted, very 

 small, or strikingly leaf-like. 

 The head is long and horizontal, 

 while in most of the species the 

 antennae are rather short. The 

 legs are of the ordinary type, 

 being made neither for jumping 

 nor seizing, and, as a rule, quite 

 long and stick-like. When the 

 insect is at rest the front pair are 

 stretched out in front so as to 

 increase the resemblance to a 

 twig. The characters by which 

 the insects of this family are 

 classified are similar to those used in other families in the Orthoptera. The antennae, 

 however, acquire more or less importance in different genera. Although there are a 

 few representatives of this family in the United States, they find their most congenial 

 home in the ti'opics, where some of the species attain to over a foot in length, ex- 

 clusive of the legs. 



The walking-sticks ai;e strictly herbivorous, and in color closely imitate the plants 

 upon which they feed. Their eggs are oval or elliptical, and have a lid on the front 

 end which is pushed open by the young larva when it is ready to escape. They are 

 dropped singly on the ground. Tlie larvae differ but little from the imago except in 

 size and in their greenish color. Their mode of life varies somewhat from that of their 

 parents. During the first few weeks they generally live upon grass and low bushes, 

 where they readily drop to the ground when disturbed, thereby escaping notice. The 

 transformations of but few of the Phasmidse have been studied. We cannot, there- 

 fore, be positive as to the number of moults suffered by the representatives of the 

 various genera. The history of Diapheromera femorata has been carefully studied 

 by Riley. The eggs are oval, slightly compressed at the sides, polished black in 

 color, with a ventral whitish stripe, and look something like small leguminous seeds. 

 They are tough and are simply dropped upon the ground' from whatever height the 

 female happens to be, so that during the latter part of autumn where the insects are 

 common they produce upon the dry leaves a constant pattering not unlike that of rain. 

 The number of eggs laid by a single female is near a hundred. They remain upon the 



Fig. 252. —Leaf insect. 



