April, '13] ESSIG: SAN JOSfi SCALE CONTROL 273 



saw results of a test spraying where whitewash was used, and in almost 

 every instance the tops received no treatment. If the application is 

 thorough the dilution can be greater. The one to thirteen dilution is 

 efficient if the work is good, and the one to nine will give no better re- 

 sults if large patches on the trees are left untouched. I believe that 

 it is better to use an excess of a somewhat weakened spray than to 

 use an insufficient amount of a real strong solution. 



In order to make the areas sprayed more apparent and to avoid 

 missing portions of the trees, some of our growers add ten pounds of 

 slacked lime to every one hundred gallons of the diluted lime-sulphur 

 spray. 



Under proper management one application should serve to keep the 

 trees in good condition for one or two years. 



4. Time of applicatiofi: Fall and winter are the proper times to 

 spray for 1>his scale. It must be remembered that the pest is then 

 more or less dormant. In many parts of California the winters are 

 mild and the resistant powers of the scale are not so great as in the 

 colder regions, and it is quite possible that somewhat better results 

 can therefore be obtained. Though I am not at all familiar with work 

 under your conditions, I should think that it would be advisable to 

 begin spraying in the fall, just as soon as most of the leaves have fallen, 

 and before the scale becomes too dormant. 



Natural Enemies. The use of natural enemies has been responsi- 

 ble for much good in many of the states, and especially in California. 

 Many badly infested orchards have been mysteriously rid of the scale 

 much to the surprise of the unsuspecting orchardists. The important 

 natural checks — the internal parasite, Aphelinus fuscipennis How., 

 and the predaceous two-stabbed lady-bird beetle, Chilocorus hivul- 

 nerus Muls., both of which are native insects — are responsible for most 

 of this work. The average orchardist is not content to leave the subjec- 

 tion of the scale to these natural foes, and this attitude has been 

 abundantly justified by the many failures of these beneficial insects. 

 However, they are always to be sought as a valuable adjunct to arti- 

 ficial control and in not a few cases they have proven the salvation 

 of an industry. 



Conclusion. In conclusion I might state that under normal con- 

 ditions the control of the Pernicious Scale in California and elsewhere 

 is exceedingly successful. I can remember when the presence of this 

 pest in an orchard meant complete condemnation of the fruit, while 

 today little is thought of such an occurrence. In fact, many of the 

 localities which were badly infested are today comparatively free of 

 the pest; a condition due to a more thorough understanding of the 

 control methods herein presented. 



