NET- WINGED INSECTS. 261 



is said of the Cockroaches? What of the Earwigs? What of the 

 Praying Mantis ? What of the Walking-stick ? Of the Leaf In- 

 sect ? What does the family Saltatoria include ? What is said of 

 the Mole Cricket ? Of the Tree Cricket ? How do the Grasshoppers 

 differ from the Crickets ? What is said of the Katydid ? In what 

 way is its ssund produced? How do the Locusts differ from the 

 Grasshoppers ? In what countries are they at times exceedingly nu- 

 merous ? Describe their appearance in Russia in 1825, and the means 

 taken to destroy them. What is said of their ravages ? Give the de- 

 scription from the Prophet Joel of the invasion of an army of Locusts. 

 What is- said of these insects as food ? 



CHAPTER XXVI. 



NET -WINGED INSECTS. 



449. THE insects of the order Neuroptera, or Net- wing- 

 ed Insects, have, like the Coleoptera and Orthoptera, a 

 mouth fitted for mastication, but differ from them in their 

 wings. They have no wing-covers, but there are com- 

 monly four thin and transparent wings, with the veins 

 forming a delicate net-work, as seen in Fig. 207 (p. 262). 

 The posterior wings are ordinarily as large as the ante- 

 rior, but in some species they are quite small, and in some 

 few entirely absent. The body is long, slender, and soft. 

 These insects are of intermediate size, none being either 

 very large or very small. There are about a thousand 

 species. The metamorphosis is not alike in all. In some 

 it is complete, the larva having a form very different from 

 the imago or perfect insect, while in others there is little 

 difference except in the absence of wings in the larva 

 and their presence in the imago, as in the Grasshoppers 

 and Locusts. By these differences the order is naturally 

 divided into two groups, in the first of which the insect 

 is active during its pupa state, while in the other it is 

 torpid during this state, except just before its last meta- 

 morphosis. Of the first group there are five families, the 

 Dragon-flies, Day-flies, Stone-flies, White Ants, and Book- 



