12 CIRCULAR 2 3 7, U. S. DEPARTMENT OF AGRICULTURE 



quantities are to be made, 8 teaspoonfuls to each gallon of water, 

 not later than July 4, with a second application from two to three 

 weeks later: Linden (basswood), horsechestnut, elm, willow, Lom- 

 bardy poplar, European white birch, Norway maple, sycamore, pin 

 oak, chestnut oak, cypress, larch, and sassafras. Boxwood and mag- 

 nolia are somewhat susceptible to injury from arsenicals, especially 

 where heavy applications of lead arsenate are used. These plants 

 should be covered with canvas to protect them from drift or drench- 

 ings while near-by trees are being sprayed. 



SHRUBS AND ORNAMENTALS 



The shrubs and ornamental plants likely to be injured as a result 

 of beetle feeding are: Flowering quince, spirea, hawthorn, althea, 

 buckeye, rose, hollyhock, dahlia, geranium, canna, evening prim- 

 rose, zinnia, China-aster, hibiscus, and Virginia creeper. These 

 plants should be treated with the lead oleate coated lead arsenate 

 as described for the protection of shade trees. Where small quanti- 

 ties of spray solution are needed, 8 teaspoonfuls of lead oleate coated 

 lead arsenate to each gallon of water should be used. All plants 

 not over 10 feet in height can be sprayed with a hand or bucket 

 pump sprayer in case power outfits are not available. 



No satisfactory spray has yet been found, however, for the 

 protection of the flowers, as it is not possible to keep the expand- 

 ing bloom covered with a film of poison. Individual flowering 

 plants, or groups of plants, can be protected by inclosing them with 

 cloth mosquito netting. Frames for holding the netting can be 

 constructed of wood or iron pipe at moderate cost. Several grow- 

 ers of choice roses have successfully protected their flowers by this 

 method. Where mosquito netting is used, it may be necessary to 

 make one or two applications of fungicide during July and August, 

 because inclosed plants are more subject to mildew than plants 

 grown in the open. 



FRUIT TREES 



Most of the fruit trees found in the cities and towns are consid- 

 ered in this circular as either shade trees or ornamental plants. 

 Apple and cherry trees and grapevines can be treated as specified 

 for shade trees. Peach and plum trees are somewhat susceptible to 

 arsenical injury; therefore the lead arsenate in the spray for the 

 protection of these trees should be 3 pounds to 100 gallons of water 

 plus 16 pounds of hydrated lime. For smaller quantities of the 

 spray solution 2 teaspoonfuls of lead arsenate and 8 teaspoonfuls 

 of hydrated lime to each gallon of water should be used. 



MISCELLANEOUS METHODS FOR DESTROYING BEETLES 



The methods recommended in the foregoing paragraphs are in- 

 tended for the protection of plants. Other methods have been worked 

 out which are intended for the destruction of large numbers of 

 beetles. They should be used, however, only when it is desired to 

 reduce the infestation without regard to protection, and the pro- 

 tective sprays already described should never be omitted if there 

 are plants that might suffer from attacks of the beetles. 



