54 



AN ECONOMIC ENTOMOLOGY. 



' ' chinch-bug, " " squash-bug, ' ' and others of equal note. The 

 term Homoptera^ or similar- winged," is used for that series in 

 which the fore-wings are uniform in texture, as in the plant-lice 

 and Cicadas. 



The order Coleoptera contains the beetles, and the name, mean- 

 ing sheath- winged," is due to the fact that the anterior wings 

 are hard and horny, unfitted for flight, and used only as a sheath 

 or covering for the posterior pair. The mouth parts are man- 

 dibulate, and the metamorphosis is complete. 



An easily recognized order is the Lepidoptera, or "scaly- 

 winged," including the butterflies and moths. Here wings and 

 body are covered with minute scales, easily rubbed ofl" and 

 resembling colored dust. The mouth parts are haustellate, and 

 form a coiled tongue, which is usually concealed beneath the 

 head, but can be readily extended at the will of the insect. The 

 metamorphosis is complete. 



Equally recognizable are the Diptera, or "two-winged" flies. 

 The single pair of wings is characteristic, and with it are asso- 

 ciated mouth parts varying much in type, but never mandibulate 

 nor forming either a coiled tongue or jointed beak. The meta- 

 morphosis is complete. 



The Hymenoptera, or "transparent winged" insects, include 

 bees, wasps, ants, and the like, and stand at the head of the 

 Class Insecta. They have two pairs of transparent wings, with 

 only a few veins ; the posterior smaller than the anterior. The 

 mouth parts are mandibulate, but the tongue is often developed 

 as a lapping organ, and sometimes greatly enlongated. The 

 metamorphosis is complete. 



To show the differences succinctly the following table may be 

 of use : 



Insects which never become winged, have the mouth feebly developed 



and the metamorphosis incomplete . Thysanura, 



All others are winged : 

 With four transparent wings, which are net-veined and flat ; mouth 

 parts mandibulate and well developed ; the metamorphosis, either 



incomplete Pseudo-neuroptera. 



or complete Neuroptera. 



With the fore-wings narrow and somewhat thickened ; the posterior 

 folded fan-like, or plaited ; mouth mandibulate ; transformations 

 incomplete Orthoptera. 



