SHADE TREE INSECTS 55 



whenever the residue from the preceding application is removed by rain or weath- 

 ering action. 



No satisfactory method has been found to protect those flowering plants which 

 are attractive to the beetles, because it is not possible to keep the unfolding 

 bloom covered with a protective residue. Also spray residue on a flowering plant 

 destroys the beauty of the blooms. Covering such plants with a wire or cloth 

 screen during the time the beetles are flying has been suggested. 



Nonflowering plants, certain vegetables, and some fruit trees may be protected 

 by keeping them coated with a spray composed of 1 pound of hydrated lime to 

 3 gallons of water. Lead arsenate is not advised for these. 



Grub-proofing an established lawn. — To kill the grubs in an established lawn 

 or other grassy area, lead arsenate without a sticker can be applied to the turf 

 at the rate of 10 poimds to 1,000 square feet. In order to spread this small 

 amount of lead arsenate evenly over such an area it may be mixed with dry sand 

 or light, dry soil to give it sufificient bulk. The lead arsenate should be washed 

 into the soil immediately^ after application, to remove it from the surface where 

 it may be a hazard to man or animals and to carr\- it down to the root^ where the 

 grubs are feeding. 



Where a power sprayer is available, lead arsenate may be applied as a spray. 

 The lead arsenate should be mixed with the least possible amount of water to 

 obtain a uniform distribution without flooding the turf. A mi.xture of 1 pound 

 of lead arsenate to 2 gallons of water, applied at the rate of 20 gallons to 1000 

 square feet of lawn, has given satisfactory results when the spray material in the 

 tank was kept properly agitated. After this spray is applied, it should be well 

 washed into the soil to remove the poison from the grass before the spray dries. 

 Turf may be treated with lead arsenate at any time of the year when the ground 

 is not frozen, but best results are obtained when the poison is applied before 

 July. 



It is advisable not to apply lead arsenate to turf where cattle graze. Children 

 should be kept from playing on recently poisoned turf until the lead arsenate 

 has been washed into the soil so that no residue remains on the surface. 



Grub-proofing a lawn under construction. — If only a few grubs are observed 

 in the soil during the preparation of the seed bed, it is advisable to have the grass 

 well established before the lead arsenate is applied. If the seed bed is prepared 

 and the grass sown in the late summer or early fall, the lead arsenate should be 

 applied the next spring when the grass has become established in order to have 

 the poison in the soil before the grubs of the next generation appear. The direc- 

 tions given for treating an established lawn should be followed. 



If many grubs are noticed when the seed bed is being prepared, it is advisable 

 to apply the lead arsenate to the ground before seeding, to prevent the grubs from 

 destroying the grass as soon as it has germinated. The lead arsenate should be 

 applied in the dry form only, and mixed thoroughly with the top soil to a depth of 

 3 inches, at least 30 days before seeding, in order to kill a large proportion of the 

 grubs before the grass germinates. Thirty-five pounds of lead arsenate to 1,000 

 square feet of surface may be used in such areas. Fine, dry, top soil should be 

 thoroughly mixed wnth the lead arsenate to give it bulk enough to be spread 

 evenly over the surface. Later the grass may be sown in the ordinary manner. 

 In areas so treated the grass is slower in germinating and growing, and is darker in 

 color than that on unpoisoned soil. Later there is little difference between the 

 two. This treatment may be expected to make the turf immune to grub injury 

 for about 10 years. Mowing, watering, and other operations may be practiced 

 as usual on treated land. Although no harmful effects have been noted following 



