190 DISEASES AND INSECT ENEMIES 



remarkable growth and the leaf development was 

 so great that it seriously interfered with the pro- 

 duction of flowers. Furthermore, we found that 

 the plants were making such rapid growth and 

 were becoming so tender and soft at the approach 

 of the spot season that great difficulty was experi- 

 enced in warding off this disease. On the whole, 

 this question may be summed up by saying that 

 by proper attention to the care of the soil and of 

 the plants little trouble need be apprehended 

 from nematodes, and it will not be necessary to 

 adopt the expensive method of sterilizing the soil. 



INSECTS AND OTHER PESTS. 



Red Spider. This little pest, which is really 

 not a spider, but a mite, is one of the worst 

 enemies with which violet growers have to deal. 

 It is present at all seasons of the year and is 

 ready at all times to begin its destructive work if 

 allowed to do so. It is difficult to estimate the 

 damage these mites do to plants, for the reason 

 that it is seldom that any plants are entirely free 

 from them and no fair comparisons can therefore 

 be made. Ordinarily when there are only a few 

 of the mites present the plants show no external 

 evidence of their attacks. As the numbers in- 

 crease, however, the leaves gradually become 

 yellowish and dwarfed, and eventually the whole 

 plant succumbs, unless action is taken to rid it of 

 the pest. 



