PKEVIOTJS WOKK WITH INSECT PARASITES. 



25 



also occurred, but was abundant and injurious. He therefore argued 

 that the insect was probably introduced from Australia into New Zea- 

 land, and that its abundance in the latter country and its relative 

 scarcity in Australia were due to the fact that in its native home it 

 was held in subjection by some parasite or natural enemy, and that in 

 the introduction into New Zealand the scale insect had been brought 

 in alone. The same thing, he argued, had occurred in the case of the 

 introduction into the United States. He therefore, in his annual 

 report for 1886, recommended that an effort be made to study the 

 natural enemies of the scale in Australia and to introduce them into 

 California ; and the same year the leading fruit growers of California 

 in convention assembled petitioned Congress to make appropriations 

 for the Department of Agriculture to undertake this work. In Feb- 

 ruary, 1887, the Department 

 of Agriculture received speci- 

 mens of an Australian para- 

 site of Icerya from the late 

 Frazier S. Crawford, of Ade- 

 laide, South Australia. It 

 was a dipterous insect known 

 as LestopJionus iceryx Will., 

 and for some time it was con- 

 sidered, both by Prof. Riley 

 and his correspondents and 

 agents, that the importation 

 of this particular parasite 

 offered the best chances for 

 good results. 



Neither the recommenda- 

 tions of Prof. Riley nor of 

 the then commissioner of 

 agriculture, Hon. Norman J. 

 Colman, nor the petitions of the California horticulturists gained 

 the needed congressional appropriations, and, since there appeared 

 at that time annually in the bills appropriating to the entomo- 

 logical service of the Department of Agriculture a clause prevent- 

 ing travel in foreign parts, it became necessary to gain the funds 

 for the expense of the trip to Australia from some other source. 

 A movement was started in California to raise these funds by 

 private subscription, but it was never carried through. In an 

 address given by Prof. Riley before the California State Board of 

 Horticulture at Riverside, Cal., in 1887, he repeated his recommenda- 

 tions. During the summer of 1887 he was absent in Europe, and the 

 senior author, who was at that time the first assistant entomologist 

 of the department, by correspondence secured from Mr. Crawford 

 numerous specimens of Icerya infested by the Lestophonus above 



Fig. 4.— The Australian ladybird ( Novius cardinalis), an 

 imported enemy of the fluted scale: a, Ladybird larvae 

 feeding on adult female and egg sac; 6, pupa; c, adult 

 ladybird; d, ornnge twig, showing scales and lady- 

 birds, a-c, Enlarged; d, natural size. (From Mar- 

 latt.) 



