264 Appendix. 



possible in that circumscribed locality in Central California. Where the work 

 was properly done we have been able to control, in large measure, the codling 

 moth and consider our experiments extremely successful. As I stated, the 

 object of my visit here is more to find out than to teach. We know that you, 

 here in Oregon, have some extremely successful orchardists, that you have 

 been able in many cases to control the codling moth, and your experience 

 will be of assistance to us in California. We hope that we may be able, also, 

 to help you. While I was listening yesterday I heard a great deal of the beau- 

 lies of the Northwest and its wonderful production of fruit, and have noted 

 one fact that has been gratifying to hear, and that is, that you always com- 

 pare with California, you always use California as a criterion. That is very 

 gratifying to me, and I believe that is as it should be ; Oregon is all right, 

 and I look upon the States of the Pacific Northwest as beautiful gems in the 

 crown of California, the queen of the Pacific. We certainly shall learn of you 

 all that we can in the matter of insect control. 



We have found in the South that we do not always get satisfactory results 

 from the use of Paris green, because of the injury to the foliage. We find 

 that we frequently get better results in this respect from the arsenite of lime 

 in the Kedzie formula, or arsenite of lead, than from Paris green. We explain 

 this in this way : Paris green is generally considered to be insoluble in water, 

 but. under certain conditions, appears to be slowly soluble. In the Pajaro 

 Valley we spray the Paris green on the trees, and over night it is moistened 

 by the fog, and we thus get conditions which seem to place the material in 

 solution. Now, while we may not get the characteristic burning, that is, the 

 browning or scorching of the leaves, we may get a chronic arsenical poisoning 

 where the leaves absorb the free arsenic in solution, so that in some cases we 

 have had the leaves of affected trees fall some two months ahead of time, 

 which has been somewhat disastrous. Taking the Kedzie formula of the lead 

 arsenite we nave not had that effect. We have also found that in the com- 

 parison between the Kedzie formula and the lead arsenicals, the lead arsenicals 

 while being as efficacious as poisons, are superior, when used properly, to the 

 lime, inasmuch as from them we get no discoloration of the fruit and little 

 danger of destroying foliage. We have carried our series of spraying experi- 

 ments on tender foliaged plants, such as the bean. Where we have used the 

 Paris green, alone or with lime, bean foliage v.'as destroyed. Where we have 

 used the lead arsenical or Paris green with a slight admixture of crude oil 

 (petroleum) we have not burned eA'en this tender foliage. If we take an 

 analysis of certain of the brands of the commercial lead arsenite we will find 

 that it contains a certain percentage of asphaltum. The use of the oil may 

 be an important addition to the home-made material. By this method we cover 

 each grain of the material we are using with a slight film of oil which keeps 

 the arsenical from direct contact with the moisture on the leaf, and the con- 

 sequence is we got no burning. 



From our California experience we look upon the Paris green today as a 

 desirable compound where the nights are dry, and that is a condition throughout 

 most of California, but where there is considerable atmospheric humidity we 

 may find it advisable to switch off from the use of Paris green and choose 

 either between the lime arsenite or the lead arsenite, or add the oils as indicated 

 above. We must also bear in mind the facts presented in Prof. Woodworth's 

 paper, that the time to spray is dependent almost entirely upon the condi- 

 tion of the moth or worm, and not altogether upon the condition of the 

 tree or the fruit. You will understand that in California, at least, the rational 

 Ijrogram Prof. Woodworth presents is a possibility of much more effective work 

 than usually obtains. 



I note from conversations I have had witli some of the entomologists 

 present at this meeting that much stress is laid upon getting the poison into 

 the calyx cup. I do not want to say it is not desirable, because under some 

 conditions it is extremely desirable, but the experience in California, as pointed 



