108 MARYLAND AGRICULTURAL EXPERIMENT STATION. 



and Jajianese Euonyniiis affected l\v CJdonaspis cuonynii as also on a 

 hedge of Japanese quince affected by the common Scurvy Scale Chionaspis 

 furfurus. The resin washes were also found in experiments upon the 

 Same insects to be less effectual than they are in California. 



The results since obtained at the Department of Agriculture give a 

 very high relative value to the ordinary commercial whale-oil soap, ap- 

 plied at the rate of two pounds or more to the gallon of water, and next 

 to this the resin wash used five or six times stronger than indicated in 

 the ordinary formula. My own more recent experience this winter con- 

 llrms the ethcacy of the strong whale oil soap solution. Unfortunately 

 both these washes are expensive, but in this as in so many other things 

 the best, even if the most expensive, is the cheapest, in the end, and 

 where trees have already become infested by this pernicious insect they 

 will be very likely to succumb in the end, unless some remedial measures 

 are taken or unless some special efforts are made to introduce and 

 encourage the parasites and natural enemies already treated of. 



]\Ir. Howard, in his latest article, already referred to, summarizes 

 in the following record a series of experiments in November and Decem- 

 ber, 1894, under rather disadvantageous circumstances, because of heavy 

 rains intervening : 



Whale-oil Soap. 



1. Three pounds dissolved in one gaUon of water. Fatal to all the scales on the 

 trees sprayed with it. 



2. Two pounds in one gallon of water. Same result. 



3. One and one-lialf pounds in one gallon water. Fatal to ninety per cent, of tlie 

 scales. 



4. One pound in one gallon of water. Fatal to eighty per cent, of the scales. 



5. One-half pound in one gallon of water. Fatal to one-half the scales. 



Resin Wash: 



6. Six times summer strength. Resin, 120 pounds ; caustic soda, 30 pounds ; fish-oil, 

 15 pints ; water sufficient to make 100 gallons. Fatal to all the scales on the tree sprayed 

 with it. 



7. Four times summer strength. Resin, 80 pounds; caustic soda, 20 pounds ; flsh-oil, 

 10 pints : water sufficient to make 100 gallons. Fatal to eighty-flve per cent, of the 

 .scales. 



Kerosene Emulsion. 



8. Pure. Fatal to ninety per cent, of the scales. 



9. One part of emulsion and one of water. Fatal to eighty per cent, of scales. 



10. One part of emulsion and two of water. Fatal to one-half the scales. 



11. One part of emulsion and three of water. Fatal to thirty per cent, of scales. 



12. One i)art of emulsion in four of water proved fatal to only a small percentage of 

 scales. (On potted plants in Insectary.) 



13. One part of the emulsion in six of water, fatal to a very small percentage of 

 scales. (On potted plauts in Insectary.) 



