58 THE NOETH DAKOTA FARMSTEAD 



trees will justify a very heavy watering just before the ground 

 freezes, to provide considerable soil moisture for the protection of the 

 roots. In the shelter belt manure mulching is not always practical. 

 The mulch is there provided by thorough cultivation during the entire 

 summer. 



INSECT PESTS AND STANDARD SPRAYS 



All insects can be divided into two main groups, those with 

 biting mouth parts that eat the foliage and those with sucking 

 mouth parts that suck the sap from the leaves and stems. The same 

 spray material cannot be used for both these groups. Those with 

 biting mouth parts can be poisoned with a spray of Paris Green, y 2 

 Ib. to 50 gal. water, or with arsenate of lead, 2 to 4 Ibs. to 50 gal. 

 of water. The arsenate of lead is the better of the two, because it 

 adheres to the foliage for a longer time. Sucking insects must be 

 combatted by a spray that will kill the insect by coming in contact 

 with it. Such materials are soap solutions, principally of whale oil 

 soap, 1 Ib. to 6 gal. water for use on foliage. tobacco decoctions 

 and kerosene emulsion, made by dissolving half a pound of hard 

 soap in 1 gallon of boiling water, then adding 2 gallons of kerosene, 

 emulsifying the mixture into a creamy mass by stirring or running 

 through a spray pump, diluting this material with 3 or 4 parts of 

 water to one part of the emulsified solution for winter tree spraying, 

 and with 8 to 10 parts of water for use when the leaves are on the 

 trees. 



These general instructions apply to vegetables, flowers, fruit, 

 forest and ornamental trees and shrubs. 



COMMON TREE AND SHRUB INSECTS 



The most common serious insect pests of forest trees and ornamen- 

 tal trees and shrubs are: Canker Worm, attacking most forest trees, 

 Box-Elders and Elms, denuding them of early spring foliage. Can 

 be controlled by spraying with arsenate of lead early in the spring 

 to poison the caterpillars, or placing a band of tar or some other 

 sticky material around the trunk of the tree in August to catch the 

 female moths as they climb up the tree to lay their eggs. It is best 

 to put this sticky material on a piece of building paper or burlap so 

 as to be sure it will not injure the tree. Where these methods are 

 not practicable continuous summer cultivation and burning the in- 

 fested leaves will tend to control this insect. 



The Cottonwood Leaf Beetle, attacking the Cottonwoods and 

 Willows: the Willow caterpillars, attacking the Willows and Poplars 

 are the most serious biting insects of early summer. The Box Elder Leaf 

 Roller is a biting insect doing its damage in late summer. 



