CHAPTER XXIV 

 ORDER LEPIDOPTERA* 



The Moths, the Skippers, and the Butterflies ' 



The winged members of this order have four wings; these are mem- 

 branous, and covered with overlapping scales. The mouth-parts are 

 formed for sucking. The metamorphosis is complete. 



The members of this order, the moths, the skippers, and the butter- 

 flies, are well known to every observer of nature. Their most easily 

 observed distinguishing characteristic is that which suggested the name 

 of the order, the scaly covering of the wings and body. Every lad that 

 lives in the country knows that the wings of moths and butterflies are 

 covered with dust, which comes off upon one's fingers when these insects 

 are handled. This dust when examined with a microscope is found to be 

 composed of very minute scales of regular form. The body, the legs, 

 and other appendages are also covered with scales. 



The scales of Lepidoptera are modified setas. That is, they are setae 

 which, instead of growing long and slender as setae usually do, remain 

 short, but grow very wide as compared with their length. Every grada- 

 tion in form can be found from the ordinary hair-like form, which occurs 

 most abundantly upon the body, to the short and broad scale, which is 

 best seen upon the wings. 



There is a great difference among the 

 insects of this order regarding the regular- 

 ity of the arrangement of the scales upon 

 the wings. With some of the lower moths 

 the scales are scattered irregularly over the 

 wings. But if the wing of one of the higher 

 butterflies be examined with a microscope, 

 the scales will be found arranged in regu- 

 lar, overlapping rows; the arrangement be- 

 ing as regular as that of the scales on a fish 

 or of the shingles on a roof (Fig. 323). In 

 the upper part of the figure the membrane 

 is represented with the scales removed. 



The chief use of the scales on the body is for the protection of the 

 insect. Another use of the scales may be to strengthen the wings. 

 A secondary use of the scales is that of ornamentation; for the beautiful 

 colors and markings of the moths and butterflies are due to the scales. 

 If the scales are removed the colors of the insects are destroyed. 



The mouth-parts of moths and butterflies are especially adapted for 

 sucking nectar from flowers. If the head of a butterfly be examined, 



* Lepidfiptera : lepido {\tirls, \inl5os), scale; pteron (irrepov), a wing. 



183 



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Fig. 323. — Part of wing of butterfly, 

 greatly magnified. 



