516 



INVERTEBRATE MORPHOLOGT. 



forms, being in the Butterflies usually club-shaped, while in 

 male moths they are frequently featherlike, though more sim- 

 ple or filiform in the females. The mouth-parts are adapted 

 for sucking, forming in most cases a long tube, which, when 

 not in use, is coiled into a helix. In the smaller members of 

 the group (Microlepidoptera), which are in many respects the 



most primitive and include such 

 forms as the Clothes-moth (Tinea), 

 the moth of the Apple-maggot (Car- 

 pocapsa), the leaf-rollers (PyralidaB), 

 etc., the sucking arrangement is by 

 no means perfect, the mandibles being 

 present, and the maxillae and labium 

 resembling in structure the corre- 

 sponding parts in biting insects, ex- 

 cept that the two inner terminal 

 plates of the labium are united to 

 form a short tube. In the higher 

 forms (Macrolepidoptera), however, 

 the mandibles (Fig. 241, mn) are quite 

 rudimentary and the labium is much 

 reduced in size, though its palps (Ip) 

 are frequently large and well de- 

 veloped. The sucking-tube is com- 

 posed of the two maxillae (m) which are produced into two 

 long filaments grooved on their mesal surfaces, and by their 

 apposition the tube is formed. 



The metamorphosis is in all cases complete, the larv^ 

 being wormlike structures known as caterpillars. Their 

 mouth-parts are adapted for biting, and they live for the 

 most part upon the leaves of various plants, frequently ac- 

 complishing much destruction. This is especially the case 

 with the Tent-caterpillar (CKsiocampa), which lives in colonies 

 enclosed within a web which is extended from twig to twig as 

 the leaves are gradually eaten ; various kinds of trees suffer- 

 ing from its ravages. The shade-trees in cities, especially 

 the Horse-chestnut, are sometimes greatly injured by the 

 caterpillar of the Tussock-moth (Orgyia), and the larvae of the 

 common white Cabbage-butterfly (Pieris) feed upon the leaves 



Fig. 341.— Head of Moth. 

 Sphinx ligustri, showing 

 MOUTH-PABTS (after New- 

 port). 



a = auteuuee. 

 i = labrum. 

 Ip — labial palp ; that of 



left side removed, 

 m = maxillae. 

 mn = mandible. 

 o = eye. 



