29 



a season, the exact number of which is still iu doubt, but possibly 

 as many as five. 



Food Plants. 

 The list of food plants of the San Jose scale insect, so far as 

 known, are as follows : apple, pear, peach, plum, cherry, apricot, 

 quince, flowering quince, almond, spiraea, raspberry, rose, haw- 

 thorn, cotoneaster, gooseberry, currant, flowering currant, per- 

 simmon, elm, osage orange, linden, euonymus, acacia, English 

 walnut, pecan nut, alder, weeping willow and laurel-leaf willow. 



Methods of Distribution. 



As the mature female is wingless, and fixed to the tree on which 

 she feeds, she will not be likely to cause other regions to become 

 infested unless the tree to which she is attached is removed. Her 

 progeny, however, when they are moving about freely, may be 

 transported to places more or less distant by other insects, birds, 

 larger animals or even by man ; but the chances are not favorable 

 for 'any very wide dispersion in this way. They may, however, 

 be carried from one tree to another at no great distance. Infested 

 'fruit may be transported from one part of the country to another, 

 and by chance be left in some place where it is possible for the 

 young to crawl to some suitable food plant ; but by far the most 

 favorable method for the wide distribution of this insect is on 

 nursery stock, and to this the most careful attention should be 

 given. 



It will be decidedly to the advantage of every dealer in nursery 

 stock to take measures to clean his trees from this scale and to 

 keep them free, for, if this be not attended to, purchasers will 

 find other and more satisfactory parties to deal with. 



Remedies. 



If only a comparatively few small trees are infested in a nursery 

 or orchard, the best way is to burn them, taking great care that in 

 doing so none are scattered. There is no method of destroying 

 insects equal to cremation. 



Professor Howard, after having a long series of experiments 

 performed for the purpose of ascertaining the best and most 

 economical method of destroying this insect, says : "The only 

 perfect results that have been reached have come from the applica- 

 tion of two pounds or more of commercial fish-oil or whale-oil 

 soap to a gallon of water soon after the leaves fall in the autumn, 

 and from the application of a resin wash of six times the nor- 

 mal summer strength. The effects following the application of 



