164 ECONOMIC ZOOLOGY AND ENTOMOLOGY 



tain Locust, Melanoplus spretus, which used to appear 

 occasionally in countless numbers in the grain fields of the 

 Mississippi valley, travelling a thousand miles by a single flight 

 from the Rocky Mountain plateau, is no longer such a danger, 

 but there are many other non-migratory species of grass- 

 hoppers which constantly attack the field crops. Some of 

 these injurious Orthoptera are referred to in Chapter XXXVI 

 and remedies for their attacks described. 



Order Euplexoptera. The Euplexoptera, or earwigs, com- 

 prise a small number of insects which were formerly included 

 in the Orthoptera. They are small brownish or blackish insects 

 readily recognized by the curious forcep-like appendages on 

 the tip of the abdomen. They are either winged or wingless, 

 and when winged have small thickened wing-covers extending 

 only about half way to the tip of the abdomen with the well- 

 developed, nearly hemispherical hind wings compactly folded 

 underneath them. Earwigs are nocturnal in habit, and feed 

 by means of their biting mouth-parts on ripe fruit, flowers 

 and other vegetable food. Despite the name they have 

 nothing to do with ears. The young undergo an incomplete 

 metamorphosis, and closely resemble the parents, except in 

 size, from the time of their hatching. 



Order Hemiptera. The Hemiptera, or sucking bugs, 

 cicadas, aphids, scale-insects, etc., compose a large order which 

 includes over 5000 species in North America, representing a 

 large variety of insect life. Many of them are of great econo- 

 mic importance. Some of the most destructive crop pests and 

 most discomforting insect scourges of man and the domestic 

 animals belong to this order. The chinch-bug of the corn and 

 wheat fields of the Mississippi valley, the tiny sap-sucking 

 aphids or plant-lice and phylloxera, and the insignificant- 

 looking scale-insects cause annual losses of millions of dollars 

 to American fields, orchards and vineyards. 



The mouth-parts in all the Hemiptera. are arranged to form 

 a piercing and sucking beak capable of taking only liquid 

 food. This food is usually the sap of living plants or the blood 

 of living animals. The wings are typically four in number, 

 although some species have but two wings and others none. 



