234 ANNUAL, REPORT OF THE Off. Doc. 



iL .iL lliat time caused iu California orchards. He (considered it the 

 most pernicious scale liuown to him and found il on all deciduous 

 fruits except black Tartarian cherry. 



It spread rapidly throughout tlie fruit regions of the Pacific coast 

 and caused serious injury on every Jiand. It was fought with all 

 the usual insecticides with more or less success and, in the experi- 

 ments made, the lime, salt and sulphur wash was developed. This 

 proved peculiarly adapted to California conditions, and turned out 

 uniformly satisfactory results when the proper methods of prejjara- 

 tion and application were fully understood. 



Meanwhile the citrus orchards became infested by another scale 

 insect, introduced from Australia or some one of the neighboring 

 countries, and this proved so much more destructive that, for a time, 

 the jjernicious scale was deemed scarcely worthy of consideration. 

 The new scale was much larger, with a prominent white egg case in 

 the female, and was called the Cottony Cushion Scale. Though at 

 first attacking citrus trees, it soon invaded deciduous orchards as 

 well, and, resisting all the known insecticides, brought the fruit 

 growers face to face with failure. 



Relief came with the discovery of the natural check to this 

 insect and its introduction into California. In a marvelously short 

 time the Cottony Cushion Scale was under control, and then it was 

 realized that in many sections of South California the San Jos^ Scale 

 was no longer a destructive pest. It was practically kept in check 

 by natural enemies, and these were said to be certain species of 

 Australian lady-birds belonging to the genus, Rhisohius, which had 

 been introduced with Yedalia, to fight the Cottony Cushion Scale. 

 This was the condition of affairs when, in 1896, I visited the Pacific 

 coast to secure, if possible, such information as might guide the New 

 Jersey horticulturists in their tight against the pernicious scale in 

 that State. 



TREATOIENT AND NATURAL CHECKS IN CALIFORNIA. 



In Southern California the insect is really under control, and the 

 effective agents are, first, the twice-stabbed lady-bird, Chllocorus 

 Mvuhier^us; second, a minute parasitic wasp, Aphelinus fuscijJeiinis. 

 There were some other species found feeding on the scales, but they 

 were of no great importance in comparison with those already men- 

 tioned. 



