ORANGE PESTS 



1499 



Yellow Scale 



For Control, see Red Scale, under 

 Grape Pests. 



DOSAGK TABLE FOR FUMIGATION 



The amount of cyanide used depends 

 upon the pest to be treated. Accordingly 

 several schedules (Fig. 1) have been 

 made, based upon dosage schedule No. 1 

 for purple or red scale, made by R. S. 

 Woglum. This dosage consists of li^ 

 ounces of potassium cyanide to every 100 

 cubic feet of air space. The schedule 

 dosage for black scale usually consists of 

 three-fourths of schedule No. 1 and is 

 designated dosage schedule No. %. 



It sodium cyanide is used the dosages 

 are reduced 25 per cent. 



Black Scale 



Eitlier dosage schedule No. % or % for 

 potassium cyanide or '•_. for sodium cya- 



nide. The smaller dosage is recommend- 

 ed only where there is an even hatch of 

 very young scale insects. 



Purple, Bed. Yellow Scale 



Use dosage schedule No. 1 for potas- 

 sium cyanide and No. % for sodium 

 cyanide. 



Mealy Bug- 



Tlie same dosage as for black scale 

 gives almost as good results as the 

 heavier doses. 



Length of E.xposure 



The time required to complete the gen- 

 eration of the gas is not long, but it is 

 advisable to leave the tents upon the 

 trees for at least 45 minutes after the 

 dosage is placed under the tent. Some 

 prefer 30 minutes, while others insist 

 upon a full hour. 



Distiiiice Around Trees 



iMg. 1. 



chcdule No. 1. Tlio lirsr t>w dnsntrt's sliouhl ho tiitutilod. 

 (U. S. Departmei3t Agriculture.) 



