FRUITS AND VEGETABLES UNDER GLASS 



CHAPTER XVII 



DISEASES AND INSECT PESTS THAT AFFECT PEACHES 

 AND NECTARINES 



THE successful grower of indoor fruit must wage an incessant figiit against 

 insect pests and diseases. These affect both the Peach and Nectarine 

 more or less, and if not checked will spread more rapidly than on trees 

 grown in the open field or garden. This is especially the case with San Jose scale. 

 The extra heat and humidity of the house favor the rapid increase of this noxious 

 pest. When I was working for some years in a district where San Jose scale 

 was very prevalent on all outside fruit trees and shrubs, I decided to import 

 all my Peaches and Nectarines, with the view to having clean stock. But my 

 precaution was useless, for while I got my trees in good condition, San Jose 

 scale appeared within a year, although I did not come into close contact with 

 the scale outside, the infected trees being some distance away. It seems, there- 

 fore, that small birds and bees, and especially the bumble bee with its hairlike 

 feet, are the means of carrying and spreading this pest. The scale, when just 

 hatched, is as fine as dust. At that time hydrocyanic acid gas was little known, 

 and the only means we had of keeping the pest in check was lime, sulphur and 

 salt. This formula was troublesome to use in a close structure, with white paint 

 to protect, but it was fairly successful. We discarded it later in fa\or of liydro- 

 cyanic acid gas. 



It was different with the Peach borer, however, for while we used the lime- 

 sulphur formula about four years and succeeded in keeping the borer down, 

 when we discarded this for the gas, the borer appeared again in numbers. I 

 have found in my long experience with different insecticides and fungicides, 

 that we may learn something from all of them. 



Insect pests, if allowed full sway, will very soon weaken the constitution 

 of even the most healthy and vigorous of trees. During the Winter months:, 

 or while the temperature is low, they hibernate in their burrows under tiie bark, 

 reappearing and beginning their work of destruction when the warm weather 

 comes or the heat is turned on. Larvae of various sizes may be found on the 

 trees at almost any time, ranging from very small ones to those that are nearly 

 full grown. The period of preparation and emerging of the moth being extended, 

 there will be different crops during the season. The borer turns into a cocoon 

 and comes to the surface just before the fly emerges from the same. With 

 close attention the borer may be gathered up before the fly leaves its cage. It 



