24 PRINCIPAL CACTUS INSECTS OF UNITED STATES. 



of aniline dyes. For several years the commercial cochineal crop of 

 the world amounted to more than 7.000.000 pounds. Although the 

 amount produced now is very much smaller, it seems to be more or less 

 constant. In 1909, the last year for which statistics are available, the 

 United States imported 102,000 pounds of a value of $33,875. Prac- 

 tically all of this supply is obtained, either directly or indirectly, 

 from the Canary Islands. The average annual importation into the 

 United States for seven years ending with 1909 was 130,000 pounds. 



Cochineal is now used as a coloring matter for fine fabrics, certain 

 kinds of ink, and confectionery. It is also used as a coloring medium 

 for solutions and emulsions, being found practically in every drug 

 store in the country. For many years it was used more or less regu- 

 larly as an anodyne, but this use has been largely discontinued. 



The cottony cochineal insect occurs practically throughout the 

 cactus region in the United States. It has been found to be abundant 

 as far north as Young County, Tex. It is attacked by a large num- 

 ber of predaceous insects. These tend greatly to hold the cochineal 

 insect in check. Otherwise it would be a pest of prime importance 

 on Opuntia plantations. As it is, it not infrequently becomes so 

 abundant as to destroy portions of the plants and, on occasions, even 

 as far north as central Texas, it has been found that entire plants 

 have been destroyed. 



ENEMIES. 



The insect enemies of the cotton}' cochineal insect, so far as known, 

 consist of eight species of Coleoritera and three of Lepidoptera. as 

 follows : 



COLEOPTERA. 



Exochomus lathiscidus Casey; Exochomus marginipenrds Le Conte; 

 Cycloneda munda Say; Chilocorus cacti Linnaeus; Tlyperaspis trif ar- 

 eata Schaeffer; Tlyperaspis cruenta Le Conte; Scymnus loeic^ Mul- 

 sant; Scymnus hornii Gorham. 



Lepidoptera. 



Lcetilia coccidivora Comstock; Zophodia dilatifascieUa Kagonot; 

 Solaria ardiferella Hulst. 



CONTROL. 



Attention has been called to the fact thai in the United States the 

 insect enemies of the cottony cochineal insect prevent its reaching 

 great numbers until the middle of summer. In artificial plantings at 

 times it may be necessar}^ to resort to remedial work. In such cases 

 the best plan to follow will be to remove the masses on the joints 

 b}' means of a very stiff brush or to burn them with a torch. In some 

 cases spraying with kerosene emulsion or the lime-sulphur mixture 

 might be followed, but the extensive secretion of the insect will 

 interfere greatly with the application of any insecticides. 



