[433] SCIENTIFIC MANUAL. 147 



are caterpillars, and have six true legs, and from four to 

 ten fleshy prop legs. Pupae with the cases of the wings 

 and of the legs indistinct and soldered to the breast." 



"Some kinds of caterpillars are domestic pests, and de- 

 vour cloth, wool, furs, feathers, wax, lard, flour and the like ; 

 but by far the greatest number live wholly on vegetable 

 food, certain kinds being exclusively leaf-eaters, while oth- 

 ers attack the buds, fruit, seeds, bark, pith, stems and roots 

 of plants." 



Insects of this order are by far the most injurious, both 

 as domestic pests and as destroyers of vegetation, They 

 pass through four stages, viz : the egg, the larva, pupa and 

 imago, or perfect insect. The instincts of these insects 

 teach them to deposit their eggs where the larvae, the only 

 state in which they are injurious, will have appropriate food 

 as soon as they are hatched. This is illustrated by the 

 conduct of the tobacco fly, which deposits its eggs upon 

 the leaf of the tobacco, tomato, or other plants upon which 

 the larvae feed ; the cotton moth, which deposits its eggs 

 upon the leaf of the cotton plant, and the moth of the 

 corn worm, which deposits its eggs upon the tender bud of 

 the stalk, or the young ears of corn. 



One of the most remarkable evidences of this instinct 

 is shown by the tent caterpillar, which deposits its eggs in 

 the fall upon the small limbs of those trees which are 

 among the earliest to put forth their leaves in spring. The 

 observant farmer has noticed the partiality of the moth of 

 this caterpillar for the wild crab apple tree which grows in 

 our forests, and, also, that this is the first tree in the for- 

 ests to put forth its leaves in spring. This is the caterpillar 

 which webs in the forks of apple trees in spring, and preys 

 upon the young leaves as soon as they appear. In the 

 fall it is seen in great numbers on the persimmon trees. 



The cutworm, so destructive in garden and field in 

 spring, belongs to this order. Indeed, the worst enemies 

 to our cultivated plants are found among the Lepidoptera. 



