2 CIRCULAR 3 6 5, XJ. s. DEPARTMENT OF AGRICULTURE 



report of its occurrence in the United States was in 1895 (3) , 3 in Cali- 

 fornia. In 1897 Cockerell (4, p. 20) mentioned its occurrence on 

 azalea in Washington, D. C, and in 1909 it was again noted in green- 

 houses in California (10) . Apparently these early infestations were 

 eradicated, and there were no further reports of this scale until it 

 was discovered in New Orleans. 



Although since 1925 there has been little extension of the outer 

 limits of the area infested by the camphor scale, the insect has 

 become more generally disseminated through the south-central part 

 of Louisiana. Its distribution in Louisiana in the spring of 1934 is 

 shown in figure 1. 



Figure 1. — Camphor scale infestations in Louisiana, May 1, 1934. The shaded area 

 represents a section of general infestation. The solid circles outside this area are 

 localities where the scale is found at the present time. Infestations that have been 

 eradicated are not shown. 



Because of its relative resistance to low temperatures, it is possible 

 for the insect to become a pest considerably north of its present dis- 

 tribution. It has survived temperatures of 10° F. in northern Loui- 

 siana, and at New Orleans a minimum of 19° F. in 1924 killed only 

 about 16 percent of the scales (2). The scale could probably thrive 

 under greenhouse conditions anywhere in the United States. 



This circular summarizes the information about the scale that will 

 be of interest and value to entomologists, nursery inspectors, and 

 growers who are faced with the problem of its control. More tech- 

 nical data have appeared in other publications (i, 7, 8). 



3 Italic numbers in parentheses refer to Literature Cited, p. 19. 



