127 



the species prior to the seventh decade of this century, and it seems to 

 have first attracted attention almost simultaneously in Australia, Africa, 



and America, all the evidence point- 

 ing to its introduction into Califor- 

 nia by the late George Gordon, of 

 Menlo Park, about the year 1808, 

 and probably from Australia on 

 Acacia latifoUa. 



The genus Icerya was founded by 

 Signoret, a French entomologist, in 

 1875, being based upon the single 

 species I. sacchari (Guerin). This 

 species and the one that we are now 

 dealing with are the only two spe- 

 cies of the genus. 



In my Annual Eeport as United 

 States Entomologist for 1886 1 have 

 given a very full characterization of 

 the species in all its stages, but the 

 only facts that I need draw atten- 

 tion to on this occasion are, first, 

 " That the female undergoes three 

 molts and the male two; i. e., each 

 has one more stage than had pre- 

 viously been recognized by ento- 

 mologists and observers; secondly, 

 that it differs from all other members of its family {Coccidw) in its ex- 

 tended powers of locomotion in most of its stages ; in its extreme har- 

 diness or power of surviving for a given period without food, and in its 



Fig. 24. Icerya pvrchasi, newly hatched female 

 larva — greatly enlarged (after Eiley). 



Fig. 25. Icerya purchasi, male larva, second 

 stage— greatly enlarged (after Eiley). 



Fig. 26. Icerya purchasi, a, female larva, second 

 stage — enlarged ; b, antenna— still more en- 

 larged (after Eiley). 



