57 



ment. The porcentago of scales killed was rioted from time to time 

 throughout the winter and the following spring, and in the case of 

 no tree, even where the wash had been used at considerably greater 

 strength than recommended in California, were results of any very 

 great value seen. A full record of these experiments is given in Bul- 

 letin No. S (new series) of the Division of Entomology. It was 

 noted at the time of these tests that a considerable percentage of the 

 San Jose scale died during the winter where no treatment had been 

 given, usually as much as -io or ,50 per cent perishing. Therefore, the 

 treatment was considered to be of no value unless a notably greater 

 percentage of scales were killed than would have succumbed normally. 

 Both the California wash and the Oregon wash were tested at normal 

 and double strengths. With the knowledge that the applications, as 

 reported above, were more carefully made than would be ordinarily 

 the case with farmers and fruit growers, the results were so poor 

 that this wash was not recommended for use in the East. The 

 reports of the success following its use in California, in view of these 

 results, were not easily understood, and at lirst it was thought they 

 might be founded on error, but the speaker had subsequently the 

 opportunity to visit California and personally inspect results on the 

 Pacific slope, and he found that there was no possibility of questioning 

 the efiicienc}^ of the wash in that region. The explanation was evi- 

 dently in the differences in climate between the Atlantic and Pacific 

 coasts. In the former, the wash being applied in winter, remained on 

 the trees unaffected by rains or moist weather, often for several 

 months, the wash being applied after the rainy season, in late winter. 

 In the East, on the other hand, the wash is usually subjected to wash- 

 ing rains within a few days after application, and it was believed 

 that this explained the difference in results. Later on he had again 

 taken up the investigation of the lime, sulphur, and salt wash in coop- 

 eration with the Bureau of Chemistry of the Department of Agii- 

 culture. The results of these experiments are given in Bulletin 

 No. 31 (new series) of the Division of Entomology. The wash 

 had been prepared with the use of a steam plant and after the most 

 approved California methods, and was applied almost boiling hot 

 to scale-infested trees. In this instance it killed every scale on the 

 trees, the application being thoroughly effective. The reason for 

 this seemed to be that the weather conditions following the experi- 

 ment were ver}^ favorable. The heat of the wash does not explain 

 the death of the scales because, however hot may be the liquid when 

 broken up into a thin spra}", it is cool a few inches distant from the 

 nozzle. Mr. Marlatt further stated that he still believed that, as a 

 rule, the same difference would be experienced l)etween the East and 

 West on account of the greater rainfall of the former section, and that 

 the wash was on this footing, namely, that if weather conditions are 



