24 



brown, almost black. The central portion, however, is much lighter, 

 giving the aj^pearance of a dark ring with a light center. The num- 

 ber of generations can not be accurately given, breeding going on 

 throughout the year, but undoubtedly in greenhouses and tropical 

 regions six or seven generations are not unusual, and in subtropical 

 regions five generations nia}^ be safely counted. It seems never to have 

 attracted any attention as an enemy in the orange and lemon groves of 

 California, the dry climate evidently not suiting it. The moist climate 

 of Florida and the Gulf region seems more favorable to it. 



The Red Scale of California. 



This species {Aspidiotus auraritii Maskell) (fig. 14) is entirely distinct 

 from the red scale of Florida. Its name comes not from the covering 

 scale, as with the Florida species, but from the fact that the body of 

 the mature female turns a reddish brown and shows through the thin 



^^^ - ^ ^ transparent waxy scale. 



^ '% This insect, although for 



J J years very common and de- 



K, 5 structive in the groves of 



p^ iri southern California, and 



1^ 'M enio3'ing also a cosmopoli- 



= tan distribution, has, curi- 

 ously enough, never ap- 

 peared in a destructive wa}'" 

 ^^^.^^^^^ ,, -- elsewhere in this country. 



„ ,. , . , Its origin is a matter of 



Fig. 14.— Cahlorma red scale { AsjiiiUntn^ annintii), illus- ° . , 



trating a group of the female and male scales as they SOmC Uncertaint3\ It IS nOW 

 occur on an orange leaf — enlarged about 7 diameters widelv distributed and haS 



undoubtedly been a scale 

 pest in oriental countries for centuries. It is not limited to citrus 

 plants, but may occur on almost an}^ plant growing in tropical or 

 subtropical regions. It is the most destructive and injurious of all 

 the scale insects afi'ecting the orange in California, being especially 

 troublesome in the districts about Los Angeles. So far no effective 

 parasites or predaceous insects have been found to combat it. It is 

 controlled by the oily washes, and also by the gas treatment. The 

 young are born free, or, in other words, the insect is semi-oviparous, 

 and therefore any wash which will kill the old scale will destroy the 

 young also. 



This insect has, in California, a rather well-marked variety, known 

 as the yellow scale {Aspidiotus citrinus Coq.). This variety does not 

 differ in any structural feature from the red scale, but the mature 

 insect remains yellowish in color. This variety is attacked by quite a 

 number of parasitic flies, which keep it more or less in check, so that 

 it is not, as a rule, so abundant as the red variety. 



172 



