LEPIDOPTERA 163 



rudiments. Find those rudiments on a large specimen and 

 compare with the mouth parts of the grasshopper. 



The compound eyes are large and conspicuous. 



Some of the Lepidoptera have ocelli, 1 one on either side above 

 and near the margin of these compound eyes, but they are usually 

 hidden by the scales covering the head. 



The many jointed antennae are very various in size, shape, and 

 color. 



The thorax bears three pairs of legs and two pairs of wings. 

 The wings are large, membranous, and covered with overlapping 

 scales, which are, in reality, modified hairs. These scales 

 strengthen the wings and give coloration to the species. 



The abdomen has no paired appendages. 



The metamorphosis is complete. The larvae of Lepidoptera 

 are commonly called caterpillars. They are very destructive, 

 being almost without exception injurious to vegetation. . Corn- 

 stock says, "a very few feed upon plants below the surface of 

 the water." The species which destroys scale-bugs, also those 

 attacking woolen cloth, feed upon animal matter. Caterpillars 

 are usually cylindric. The thorax bears six clawed, jointed, 

 tapering legs, which develop into the legs of the adult. The ab- 

 domen bears from two to ten thick, fleshy, non-jointed, contrac- 

 tile pro-legs (see figure of silkworm, p. 126), which are shed at 

 the last molt. The pro-legs are usually surrounded at the ex- 

 tremity by many minute hooks. The mouth parts of caterpil- 

 lars are formed for biting, hence they can be exterminated by 

 the arsenical poisons when it is safe to use them. 



The Lepidoptera pupate in chrysalids or cocoons. The 

 adult stage is the familiar winged form. It does no harm except 

 the occasional puncturing of fruit to get the juice. 



Distinctions Between Butterflies and Moths. The antennae of 

 butterflies are filiform or thread-like for most of their length, but 

 the end is thickened into a spindle-shaped enlargement or club. 

 The antennae of moths are of various forms, usually filiform or 

 pectinate (feathery), but never clubbed. Butterflies are diurnal, 

 while the moths are crepuscular or nocturnal. Butterflies 

 at rest fold the wings together in a vertical position above the 

 back. Moths spread the wings horizontally, or fold them leaf- 

 1 Comstock, p. 199. 



