CHAP. VIII. CLASSIFICATION OF INSECTS INTO ORDERS. 45 



No insect is possessed of a voice or breath sound, and those 

 which appear to sing such as the Katydids anfl Crickets 

 produce their notes by the rubbing together of certain parts 

 of the body. The Cicada, or Harvest- fly, is furnished with a 

 thin, transparent instrument, which is alternately indented 

 and relaxed, producing a sound somewhat similar to that 

 made by indenting a tin pan. 



Some insects produce a shrilling noise by elevating the wing- 

 cases, and rubbing their edges together; others rasp the inside 

 of their hind legs against the outer edges of their wing-cases; 

 some,, while on the wing, make a somewhat similar noise by 

 rubbing the front edge of the hind wings against the under 

 side of the wing-cases, Some kinds of Beetles sometimes 

 make a squeaking noise by rubbing the base of the thorax 

 against the adjacent part of the wing-cases. 



CHAPTER VIII. 



CLASSIFICATION OF INSECTS INTO ORDERS. 



Naturalists separate insects into two Sections, characterized 

 by the difference in the mouth-parts; and into seven Orders, 

 according to the number and the structure of the wings. 

 These Sections are as follows : 



SECTION 1. GNAWING INSECTS (Mandibulata). These 

 insects are furnished with a pair of jaws. 

 This Section includes the Orders as follows : 



1. HYMENOPTERA (from two Greek words meaning 

 menbrane-winged). Such as Bees, Wasps, Saw-flies, etc. 

 2. COLEOPTERA (from two Greek words, signifying 

 sheath-winged). Such as Beetles and Weevils. 



3. ORTHOPTERA (from two Greek words, meaning 



straight-winged). Such as Grasshoppers, Crickets, etc. 



4. NEUROPTERA (from two Greek words, meaning 



nerve-winged). Such as Dragon-flies, Lace-winged Flies, 



etc. 



