ENTOMOLOGY. 



563 



seconid division is made from tlie form and tcxtnre of the wings and wing cases ; 

 those vary very much in all the diflferent orders, whilst those few which are 

 apterous or possess no wings whatever, or only the vestiges of them, have been 

 classed in the orders to which they evidently belong, both from the structure 

 of their mouth and general affinity. Thus the flea, although wingless, is placed 

 among the flies or diptera, as possessing a piercer or trunk, and the rudimenta 

 of wings which are undeveloped. The number of wings is generally four. In 

 beetles the upper pair are hard or leathery, and covering another pair of a men>- 

 branous texture, and generally transparent ; in the butterfly, however, all the 

 four wings are exposed. 



Form of mouth. 



"Wings. 



Month famished with jaws, and 

 formed for biting or mastica- 

 tion. 



Mouth armed with distinct man- 

 dibles, or jaws, and also hav- 

 ing a ligula, tongue, or pro- 

 boscis for suction. 



Mouth flimished with a piercer, 

 or sucker, and not capable of 

 biting solid substances. 



Four wings: the upper pair hard or 

 leathery, and covering a pair under- 

 neath ; under wings folded only trans- 

 versely, or having a sort of elbow. 



Four wings: the upper pair hard, or 

 leathery, and covering a pair under- 

 neath; under wings folded lengthwise 

 like a fan. 



Four wings: membranous and reticula- 

 ted, the veins resembling network. 



Four wings: membranous and divided 

 into large cells. 



! Four wings, covered with colored scales 

 resembhng powder or dust ; mouth with 



I a spiral trunk only. 

 Four wings, generally placed horizon- 

 tally ; the upper pair being half of a 

 leathery texture, and the other half be- 

 ing membranous ; moixth armed with 

 a conical beak. 

 Four wings, generally slanting upwards 

 when at rest, like the roof of a house, 

 and frequently of the same membranous 

 texture ; mouth armed with a beak. 

 Two wings only ; mouth a proboscis, for 

 sucking; sometimes having small, lan- 

 cet-like appendages for piercing, con- 

 cealed inside the trunk as in the horse 

 fty, &.C. 



Coleoptera, (beetles, or sheath- 

 winged insects.) 



Orthoptera, (cockroaches, graSB- 

 hoppers, katydids, itc.) 



1 iVeurcTJtero, (dragon fly, May 

 i fly, &c.) 



1 Hymenoptera, (ichneumon i 

 > &c., wasps, bees, &c.) 



Lepidoptera, (butterflies, moths, 

 millers, &c.) 



Heteroptera, (plant bugs, squash 

 bug, chinch bug.) 



Homoptera, (cicada, or sin^gbig 

 ^ locust, plant and bark lice.) 



Diptera, (mosquito and house 

 fly, bot fly, horse fly, &c.) 



Insects also undergo three metamorphoses or changes of form. First, the 

 eggs are deposited by the female in or upon some vegetable or animal substance 

 on which the young larvae live and feed. These eggs produce grubs, cater- 

 pillars, or maggots, which are indiscriminately called larvee, from a Latin word 

 signifying a mask or disguise, as the insect iu this preparatory state bears not 

 the slightest resemblance to the full-grown and perfect insect. The larva, after 

 feeding voraciously, sheds its skin, and the pupa or chrysalis makes its appear- 

 ance ; in this second stage of its existence the pupa takes no sustenance what- 

 ever, but lies almost motionless, the limbs of the future insect appearing as if 

 wrapped iip in swaddling clothes ; hence the name pupa, which also is a Latin 

 word, signifying a puppet or baby. Finally, this outer envelope is thrown off, 

 and the perfect beetle, bee, butterfly, or fly, emerges from the shed skin, fully 



