CHAPTER XII. 



DISEASES AND INSECTS. 

 DISEASE. 



THE only diseases which attack Orchids are rot and 

 spot. During the damp months of winter, rot is 

 very apt to affect those species with thick, fleshy bulbs. 



It is caused by too much moisture in the house, or by 

 cold drip falling from the roof into the crown of the 

 bulb. During the winter, steam is injurious to Orchids 

 with fleshy bulbs, such as Cattleyas, Peristerias, Odonto- 

 glossums. 



If the rot is perceived when it has just begun, it is 

 easily checked by cutting the diseased part entirely away 

 with a sharp knife, leaving no portion of the decayed or 

 diseased bulb; then fill the wound with flowers of sul- 

 phur, keeping it dry. 



When the leaves begin to rot, the diseased part should 

 be cut clean away, and a little sulphur rubbed on the 

 parts that are cut, but the sulphur should not be allowed 

 to get to the roots of the plant. When any part of a 

 fleshy bulb becomes discolored, and the dark or dis- 

 colored part appears moist or wet, especially if any fluid 

 exudes from it on pressure, the wet or discolored part 

 should be immediately cut out, or there is danger that the 

 bulb will be destroyed, as the rot is often much more ex- 

 tensive within the bulb than the discolored appearance 

 on the outside would seem to indicate. The plant should 



