338 Landscape Gardening 



to the rose, grape-vine, etc., though it attacks some other 

 shrubs and trees. 



Remedy. — The remedy is thorough spraying with kero- 

 sene emulsion, or by the use of pyrethrum appHed just at 

 night it may be kept under control. 



Red Spider {Tetranicus telarius). — This insect is so 

 minute as to be difficult to detect with the naked eye, 

 except by the closest inspection, until it has done con- 

 siderable mischief, when its work is shown in the light 

 green or grayish color of the leaves attacked. It works 

 only in very dry and hot weather, when it increases very 

 rapidly and attacks a great many kinds of trees and 

 shrubs. 



Remedy. — As this insect cannot exist in a moist, cool 

 atmosphere, the spraying of the trees with cold water 

 applied with considerable force is a certain remedy, a heavy 

 thunder-shower often completely checking their work. 

 Dusting the foliage with flowers of sulphur when the leaves 

 are wet will also have a beneficial effect. 



Aphides {Aphis sp.). — There is hardly a species of tree 

 or shrub that is not more or less affected by aphides (or 

 plant-lice so called). One season they are abundant and do 

 much harm, and another very few and do little injury. 

 These insects increase with astonishing rapidity; a single 

 pair, it is said, may be responsible under favorable conditions 

 of food and temperature for millions of progeny in a single 

 season. They injure plant-tissues by sucking the juices 

 of the tender parts, and when numerous all of the terminal 

 shoots are stopped in growth and the tree or plant has a 

 stunted, sickly appearance. When the leaves alone are 

 attacked, they curl and roll up, and are soon covered with 

 black substances collected from the dust of the atmosphere 

 coming in contact with the sticky surface caused by the 

 exudations of the aphides. 



