104 Forty-third Report on the State Mvseum. [8] 



many instances been in a condition that rendered it absolutely 

 unfit for table use — only suitable for feeding to animals who 

 have not the privilege of selecting their food. At the same time, 

 the intelligent and enterprising fruit-grower has been able to 

 meet his hosts of insect Enemies and triumph over them by means 

 of the spraying devices and the insecticidal washes that the 

 recent experiments and studies of our economic entomologists 

 have placed in his hands and directed him how to use. The 

 ravages of the apple-worm can now be so easily controlled, that 

 worm-eaten apples should henceforth serve as an attestation of 

 the ignorance, thriftlessness, or laziness of their grower. The 

 destructive and dreaded plum-curculio is being so successfully 

 fought that it will probably soon be brought under similar 

 control. 



May I, in the above connection, offer to the notice of your 

 board an illustration of the benefit that may result from ento- 

 mological studies in the promotion of the material interests of 

 our people. 



A scale-insect, known popularly from its peculiar appearance, 

 as "the cottony-cushion scale," and scientifically as Icerya 

 Purchasi, chanced, about twenty years ago, to be brought into 

 California, on an acacia from Australia. From this plant it spread 

 to various other plants, shrubs, and trees, " attacking almost every- 

 thing," but manifesting a decided preference for the orange. It 

 especially multiplied to such a degree upon the orange trees that 

 within the last few years many thousands of them have been 

 killed, and entire orchards broken up and abandoned. Every 

 possible means known to science, in the use of washes or other 

 applications, that gave promise of killing the insect, was resorted 

 to, even to the costly experiment of constructing portable canvas 

 tents of a capacity for inclosing the largest trees, and forcing 

 within them, by the aid of an apparatus devised for the purpose, 

 the deadly vapor of hydrocyanic acid gas. Yet notwithstanding 

 all that science had been* able to accomplish, the little scale con- 

 tinued to multiply alarmingly, and to extend its range, until it 

 appeared as if the orange culture in California, yielding so large 

 an income to the State, would soon have to be abandoned. 



At this juncture the thought came that the unparalleled multi- 

 plication of this pernicious scale might largely be owing to its 

 having been brought to this country unattended by the natural 

 enemies that may have kept it under control in its native home, 



