INSECTS AND INSECTICIDES. 



specks on the leaves, fruit, or bark of his trees until it is too 

 late. The proper time for effective work is when the insects 

 first appear, and not after the trees are half killed by their 

 attack. 



Nearly all species of scale insects can be killed by the reme- 

 dies recommended in this bulletin, but some species have to 

 be treated by fumigation with hydrocyanic acid gas; especially 

 is this true on evergreen trees, it being difficult, owing to the 

 dense foliage, to reach every individual by sprays, and a suffi- 

 cient number always escape to 

 reinfest the trees. Our report 

 for 1903-04 gives a list of scale 

 insects and also illustrates many 

 species of parasites which attack 

 them, colonies of which will be 

 supplied to growers on applica- 

 tion to this department. 



Following are the sprays rec- 

 ommended for the various scale 

 insect pests: 



Winter Wash for San Jose Scale, 

 Pear Diaspis, and Greedy Scale. 

 Following is the lime-sulphur- 

 salt solution: 



Unslaked lime 40 pounds. 



Sulphur 20 pounds. 



Stock salt 15 pounds. 



Water, to make 60 gallons. 



Place 10 pounds of lime and 

 20 pounds of sulphur in a boiler 

 with 20 gallons of water, and 

 boil over a brisk fire for not less 

 than one hour and a half, or 



until the sulphur is thoroughly dissolved. When this takes 

 place, the mixture will be of an amber color. Next place in a 

 cask 30 pounds of unslaked lime, pouring over it enough hot 

 water to thoroughly slake it; and while it is boiling, add the 

 15 pounds of salt. When this is dissolved, add to the lime 

 and sulphur in the boiler, and cook for half an hour longer, 

 when the necessary amount of water to make the 60 gallons 

 should be added. 



FIG. 3. Brown apricot scale (Euieca- 

 nium armeniacum, Craw). 



