August, '19] FERRIS: LAC INSECTS 331 



University, had investigated it to some extent and had pubHshed 

 several short articles concerning it. In one of these papers' he records 

 the results of an examination of the lac and states: ''It will thus be 

 seen how closely the gum lac from Arizona agrees in characteris- 

 tic properties, structure and chemical composition with the India 

 varieties." In the same paper he states: "From observations by a 

 number of gentlemen acquainted with that portion of the country, 

 it appears that the Larrea lac is very widely distributed throughout 

 Arizona and the southern part of California (Mohave and Colorado 

 deserts), and the gum is used by the inhabitants in place of solder for 

 mending kettles." 



Professor J. H. Comstock^ states: "Another true lac insect occurs 

 in Arizona upon the stems and branches of Larrea mexicana. Judging 

 from the specimens in the Museum of this department, the lac occurs 

 upon this plant in sufficient quantity to be of economic importance. " 



In 1889 C. V. Riley^ reports that a correspondent residing at 

 Tucson, Arizona, wrote as follows concerning this lac: "I am led to 

 believe that these exudations, if properly examined, would give a 

 splendid bright red coloring matter and a very superior varnish 

 resembling the celebrated Japan Lacquer. ... I should think 

 that a man could gather from 60 to 100 pounds of clear exudation matter 

 in a working day of ten hours. " 



In 1897, Dr. L. O. Howard wrote^: "We have, however, in the 

 southwest, on the very abundant creosote bush, a lac insect occurring 

 in enormous quantity, the commercial possibilities of which have not 

 been developed." 



As there appeared to be no record that any thorough investigation 

 of this matter had ever been made the writer called the attention of 

 the Committee on Agriculture, Botany and Zoology of the National 

 Research Council to it. This committee considered it a fit subject for 

 an investigation and agreed to supply the relatively small sum neces- 

 sary to permit the writer to carry this out. 



I may state, without further delay, that the results of this investiga- 

 tion were entirely unfavorable. However, the information obtained 

 should be recorded. 



The first thing to be determined was the distribution and abundance 

 of the insect. Taking into consideration the nature of the country in 

 which the creosote bush occurs, it seemed that the investigation might 



' Stillman, J. M. American Chemical Journal, vol. 2, p. 4 (1880). 

 ' Comstock, J. H. In Report United States Commissioner of Agriculture, p. 291 

 (1880). 

 » Riley, C. V. Insect Life, vol. 1, p. 345 (1889). 

 * Howard, L. O. Bull. 9, n. s., U. S. Dept. Agric, Div. Ent., p. 38 (1897). 



