196 INSECTS 



scales," allied to the most serious of our tree pests: 

 indeed it is a tree pest, tolerated only because the insect 

 is of more value to us than the plant upon which it 

 feeds. Infested twigs are cut and stored when the insect 

 has reached the proper stage, and the adherent scales 

 and their secretions are dissolved off when they are to be 

 commercially used. Lac is a product of the Orient and 

 many of the fine polishes and lacquers of Indian, Chinese 

 and Japanese workmen are based upon it. There are 

 allied species of Coccidce occurring in tropical America; 

 but none that have been made commercially useful. 



Cochineal as a source of a beautiful crimson and 

 scarlet is well known and is also a scale insect or Coccus, 

 belonging to the mealy-bug series. It infests certain 

 kinds of cacti and is cultivated in plantations called 

 "nopalries. " It is the source of the coloring matter 

 known as crimson lake, and is a native of Mexico and 

 Central America. Before the day of aniline colors 

 cochineal was extremely valuable and important; but 

 at present the complete elimination of the insect would 

 cause little if any inconvenience. 



It is noticeable that, except in the case of silk, we 

 have substitutes for practically all the insect products 

 and even silk has been artificially produced, i.e., a 

 product so closely resembling it as to be called artificial 

 silk has been made that could be developed practically 

 in case of necessity. 



In olden days insects had a wider use, and out of 

 a plague a food supply was sometimes developed. 

 "Locusts" or grasshoppers as articles of food are known 

 among barbarous nations of many countries where 

 the insects are sufficiently abundant. The Indians of 

 the Rocky Mountain regions in America and the 

 aborigines of Africa were equally familiar with a grass- 

 hopper diet and with the methods of preparing them. 



