INSECTS AND HUMAN WEALTH 



413 



only insect that supplies food to man is the honeybee, whose 

 honey has been used by man for many centuries. 



446. Insect products. The wax obtained from bees is of 

 great practical value, but it is coming to be replaced more 

 and more by paraffin, which is obtained from petroleum. 



Another insect product of 

 growing importance, and one 

 for which no satisfactory sub- 

 stitute has yet been found, 

 is lac. The lac is used as a 

 dressing for wood and other 

 materials, as shellac, as a stif- 

 fening for felt in the making 

 of hats, as an insulating var- 

 nish in electrical work, in the 

 making of lithographer's ink 

 and of sealing wax, and in 

 increasing quantities in the 

 manufacture of phonograph 

 records. 



The cochineal, another 

 member of the scale-insect 

 family, furnishes a beautiful 

 red dye, which was formerly 

 used in large quantities. This 

 source of supply is of de- 

 clining economic importance 

 because of the rapid development of the anilin-dye industry. 



The whole silk industry rests upon the fiber obtained from 

 the cocoon covering of the silk moth. Although the chemists 

 have devised ingenious processes for making artificial silk out 

 of cotton and out of wood, we shall probably continue to 

 cultivate the silk moth for a long time to come. 



Many of the beetles may be considered as useful, since 

 they destroy large amounts of dead animal remains, as do 



Fig. 214. Destruction wrought by ants 



Part of a post completely ruined by the 

 excavations of carpenter ants. There are 

 several species of Campoiiotiis and of other 

 genera which are known to bore into wood. 

 (From photograph by New York Botanical 

 Garden) 



