MOTHS AND BUTTERFLIES. 435 



ORDER X. - - LEPIDOPTERA. 



The order of Lepidoptera, which comprises the forms familiarly known as moths 

 and butterflies, receives its name from the fact that its wings are covered with minute 

 scales laid on much like the shingles on a roof. This character alone 

 would be of little systematic importance, but we find associated with it 

 many other peculiarities of structure, all of which show the group to be 

 a natural one. The head is small and the mouth-parts are greatly 

 modified, the maxillae forming the long tongue, which, when not in use, 

 is coiled up like a watch-spring, while the mandibles are obsolete. The 

 wings are broad and membranous and are supported by numerous veins, 



I?IG. 552. Scales 



the arrangement of which affords good systematic characters. The from wings of 



... _. butterflies. 



transformations are complete. The active larva (rarely footless) is pro- 

 vided with three pairs of thoracic legs, while on the abdomen occur from one to five 

 fleshy appendages, the prolegs. The butterflies pass from the larva into a pupa or 

 chrysalis which is naked or merely enclosed in a cocoon of leaves, etc., while the 

 moths spin a cocoon of silken threads, inside of which the pupa is placed. In 

 the pupa one can Avith little difficulty trace the parts of the perfect insect; but 

 the cases which enclose the legs, antennae, wings, etc., of the adult are all firmly 

 united and not free, as for instance in the pupae of the beetles. At the proper time 

 the perfect insect emerges from the chrysalis skin, extends its various members which 

 rapidly become firm and dry, and then the butterfly or moth begins its short but active 

 life. 



In the perfect state the Lepidoptera do no damage, the slight amount of food they 

 take being in a liquid state ; in fact they are unfitted for eating any solid substances. 

 In their larval stages they are to be regarded as among injurious forms, for they feed 

 upon plants and other objects that man regards as valuable. A few of the larvas of 

 the moths are predaceous in their habits, while some of the BombycidaB repay the 

 damage they cause to various plants by the valuable textile fibre, silk. 



The large size and brilliant colors of many of the forms make them conspicuous 

 among insects, and the butterflies have long been the favorites among collectors ; but 

 the moths, on account of their immense numbers, their innumerable variations, and 

 the minuteness of many of the characters upon which systematic classification is 

 founded, have been greatly neglected by naturalists, and in the following pages but a 

 few of the more striking or more important forms can be noticed. 



The Lepidoptera are divided into two sub-orders known, respectively, as the 

 Heterocera or moths, and the Rhopalocera or butterflies, the distinctions of the popular 

 names agreeing exactly with the limits of the groups recognized by naturalists. 



SUB-ORDER I. - - HETEROCERA. 



This group of insects, popularly called moths, may be distinguished from the but- 

 terflies (Rhopalocera) by having the antennas variable in form, and the wings seldom 

 elevated in repose. The larger number fly only by night, or, if disturbed in the day- 

 time, they fly only a short distance before alighting. Many of them have two simple 

 eyes on the top of the head, one on each side, behind the antennse and near the com- 

 pound eyes ; and the greater number have a frenulum or bristle attached to the first 



