244 INJURIOUS AND USEFUL INSECTS 



effectual. It was soon made known that the symptoms 

 described were due to the attack of a scale-insect, known in 

 America as the fluted scale, or cottony cushion-scale (Icerya 

 purchast). 



This formidable plague gradually increased its range, in spite 

 of the vigorous use of poisonous washes. It was not till i888 

 that an effectual remedy was found. The late C. V. Riley, 

 Entomologist to the United States Department of Agriculture, 

 had anxiously considered the ways of checking the fluted scale. 

 He found out that it came from Australia, where it infested the 

 bushes called wattles (Acacias), that it had been introduced 

 into California about 1868, probably on Acacias, that in its 

 native country it was not a serious plague, although no 

 remedies were employed. He concluded that it must be kept 

 down in Australia by natural enemies of some kind, which did 

 not exist in California, and that the real policy was to discover 

 and import these enemies, whether parasitic or predatory. 

 Official difficulties hindered the execution of the plan. Funds 

 were not to be had, and the rules of the treasury required that 

 money granted for scientific experiments in agriculture should 

 be expended only within the national territory. It was not till 

 1888 that he found himself able to act. In that year Congress 

 voted money for sending public officers to the Melbourne 

 Exhibition. Riley was able to send a trained entomologist, 

 Albert Koebele, to visit Australia, examine the gardens, and 

 report. He found that the fluted scale, though widespread, 

 was kept in check by several insect-foes. The most promising 

 of these for Californian purposes was considered to be an 

 Australian lady-bird known to naturalists as Vedalia cardinalis. 

 This beetle, both as larva and adult, greedily devours the scale- 

 insect and its eggs, preys upon no other species, and is very 

 prolific. Koebele was diligent in procuring an abundant sup- 

 ply both of Vedalia and other insects destructive of the fluted 

 scale. He kept them torpid in the ice-house of the steamer, 

 and landed them in California without loss. The lady-birds 

 were soon distributed, and found plenty of occupation. In a 

 year and a half they had practically rid California of the pest. 



By a curious coincidence, almost at the same time that the 

 Vedalia was, by the foresight of Riley, brought to the help of 

 the Californian orange-growers, the same insect was accidentally 

 introduced into New Zealand, where the fluted scale was making 



