294 BOARD OF AGEICULTURE. [Pub. Doc. 



The first spraying should be in May or early in June, while 

 the beetles are feeding. This treatment, as has been shown 

 by Mr. C. L. Marlatt, is very efficacious, since, by destroy- 

 ing the mature beetles, egg-laying and the consequent de- 

 velopment of larva3 are prevented. Later, when the larvae 

 have appeared and the main body of the foliage has de- 

 veloped, a second application should be made. This, if 

 thorough, may suffice for the season, although in some cases 

 a third spraying may be necessary for the second brood. In 

 all cases the insecticide should be used in liberal quantities. 



With rough-barked trees many of the larvae pupate in the 

 crevices on the trunk and even far up in the tree, hence 

 scraping the bark is advisable. This will cause the larva? to 

 descend to the ground to pupate, where they will be found 

 massed in great numbers at the base of the trees, under or 

 along the bottom rails of fences near by, and in other con- 

 venient spots. In this stage they may be destroyed by 

 kerosene emulsion applied to the trunks and to the ground 

 beneath the trees. 



Spraying Outfits. — For use in parks or cities, where 

 large numbers of trees are to be sprayed, a power spraying 

 outfit will be found the most satisfactory. This consists of 

 a small engine with suitable pump, mounted on a substantial 

 one-horse truck, which also carries the spraying tank and 

 supplies. There are several styles of small engines suitable 

 for this purpose, but the writer is of the opinion that gaso- 

 line engines are the most economical, as well as being cleaner 

 and more easily attended. City Forester Gale of Spring- 

 field informs me that the gasoline engine used by him in 

 spraying is operated at a cost for fuel of one cent per hour. 

 The pump should supply at least two lines of hose, and 

 should have a release valve or " blow-off" to save strain on 

 lines of hose temporarily out of use. The tank should be 

 cylindrical with adjustable hoops, so that shrinking of the 

 staves may be taken up. Square or rectangular tanks are 

 much less durable than cylindrical ones. 



Several large hand outfits may be substituted for a power 

 sprayer, and when this is desirable an outfit similar to those 

 used by the gypsy moth committee is recommended. This 

 is composed of a one-hundred-gallon tank, mounted on a 



