178 



THE CANADIAN HORTICULTURIST. 



scales are arranged on oleander leaves. 



Lecaniums are also frequently found on 

 indoor ferns, on oranges, on lemon plants, 

 and on acalyphs, which resemble the olean- 

 der scale to a large extent, but are referred 

 to different species, such as the hemispheri- 

 cal scale and the orange scale. 



The treatment for the soft scales is simi- 

 lar to that used against the mealy-bugs. 

 Small plants are often dipped in soap or to- 

 bacco solutions. The most certain remedy 

 is the hydrocyanic acid gas treatment, simi- 

 lar to the method adopted in the nurseries 

 against the San Jose scale. A special com- 

 partment is necessary for this work, and 

 special precautions must be taken with re- 

 gard to quantities used and against possible 

 poisoning. The writer will be pleased to 

 give full directions to anyone who would 

 like to try this method. 



Among the armored scales which infest 



greenhouse plants are the Florida red scale 

 (aspidiotus ficus), and Bouche's scale (as- 

 pidiotus hederae, or nerii). Fig. 2580 shows 

 the form of the scales. The former scale 

 is nearly circular in outline, about 1-25 inch 

 in diameter, and dark brown in color. The 

 latter is not so circular, and is white. It is 

 found on a large number of green house 

 plants, such as oleanders, cycas, yucca, 

 acacia, etc. 



With these scales the treatment with soap 

 or tobacco solutions is to be commended. 

 Repetition is necessary, and when the plants 

 are dipped they should be rinsed afterwards 

 with clear water. 



There are many other scales which are 

 usually found in every large greenhouse 

 containing tropical plants, but enough has 

 probably been said to draw the attention of 

 the owners to the commoner scales and to 

 the best methods of treatment. 



Fig. 2580. (a) Bouche's scale; (b) Bouche's scale on a leaf; (c) Florida red scale; 



(d) Florida red scale on a leaf. 



