HAWAIIAN ISLANDS 371 



numerically insignificant. The entry of the Icerya into other 

 regions of the globe subsequently led to the introduction of the 

 predatory beetle into Florida, the Hawaiian Islands, New Zealand, 

 South Africa, Portugal, Italy, Syria, Egypt, the South of France 

 and Malta, with the same satisfactory results. 



The remarkable efficiency of the Vedalia is to be ascribed to a 

 combination of biological features. The insect is very active 

 both as larva and adult, which easily seeks out the sedentary 

 fluted scales on the trees. Also, it has at least two generations 

 in the time its prey is passing through but a single generation. 

 Furthermore, the Vedalia appears to be free from natural enemies 

 of its own, an important and remarkable fact. The rapid and 

 complete establishment of the Agromyzid fly Cryptochcetum 

 iceryce, which was introduced from Australia along with the 

 Vedalia, has also proved an important factor in the control of the 

 cottony-cushion scale. It has become evident that the success of 

 the Vedalia cannot wholly be dissociated with the activities of this 

 fly. The widespread publicity accorded to the success of the 

 Vedalia experiment was, in a sense, a pit-fall for the growers, who 

 soon came to believe that the expense involved in insecticidal 

 treatment against other pests was no longer necessary ; all that 

 was required was to obtain the natural enemies of a pest and 

 subjugation of the latter would follow. As Howard remarks, by 

 blinding people to other and assured methods of repression, the 

 predominant success of the Vedalia actually retarded the general 

 progress of insect control in California. 



The Hawaiian Islands. The sugar planters of these islands 

 have set an example to the rest of the world in the reliance they 

 have placed on the application of scientific knowledge to the 

 cultivation and protection of their crops. Among the severest 

 factors they have had to contend with have been the insect 

 enemies of cane. The latter are almost entirely immigrant species 

 which have become established in the Islands unaccompanied by 

 parasites or predators, which control them to a large extent in 

 the lands from whence the pests originally came (Imms, 1925; 

 Timberlake, 1927). The fact that artificial methods of repression 

 generally proved expensive, and gave poor results, had much 



