I 

 276 INSECTS INJURIOUS TO VEGETATION. 



from the egg, and, though naked afterwards, it has, hke the lappet- 

 caterpillars, a long fleshy wart on the top of the eleventh ring. 

 The history of the silk-worm, however, does not belong to the 

 subject of this treatise. 



There are several kinds of caterpillars, in the United States, 

 whose cocoons are wholly made of a very strong and durable silk, 

 fully equal to that obtained in India from the tusseh and arrindy 

 silk-worms. These insects, together with some others, whose 

 cocoons are much thinner, and consist more of gummy matter 

 than of silk, belong to a family called Saturnians (Saturniad^), 

 from Soturnia, the name of a genus included in this group. The 

 caterpillars are naked, are generally short, thick, and clumsy, 

 cylindrical, but frequently hunched on the back of each ring, 

 especially when at rest, and are furnished with a few warts, which 

 are either bristled with little points or very short hairs, or are 

 crowned with sharp and branching prickles. They live on trees 

 or shrubby plants, the leaves of which they devour ; some of 

 them, when young, keep and feed together in swarms, but separate 

 as they become older. When fully grown and ready to make 

 their cocoons, some of them draw together a few leaves so as to 

 form a hollow, within which they spin their cocoons ; others 

 fasten their cocoons to the stems or branches of plants often in the 

 most artful and ingenious manner ; and a very few transform upon 

 or just under the surface of the ground, where they cover them- 

 selves with leaves or grains of earth stuck together with a little 

 gummy matter. The escape of the moth from its cocoon is ren- 

 dered easy by the fluid which is thrown out and softens the 

 threads. The chrysalis off'ers no striking peculiarities, being 

 smooth, not hairy, and not provided with transverse notched 

 ridges. This group contains some of the largest insects of the 

 order ; moths distinguished by great extent and breadth of wings, 

 thick and woolly bodies, and antennae which are widely feathered 

 on both sides, from one end to the other, in the males at least, 

 and often in both sexes. The tongue and feelers are extremely 

 short and rarely visible. The wings are generally spread out, 

 when at rest, so as to display both pairs, and they are held either 

 horizontally, or more or less elevated above the body ; a very 

 few, however, turn the fore-wings back, so as to cover the hind- 



