11 



it to more general city use. Probably the largest elm tree in America, 

 the Dexter elm at Medford, Mass., has been successfully and eco- 

 nomically sprayed by the Gypsy Moth Commission. It is necessary 

 to have especial apparatus constructed, and it is equally necessary to 

 have the work done by men who are accustomed to i.t or at least are- 

 good climbers. The first successful work of this kind was probably 

 that done by Prof. John B. Smith, on the campus of Rutgers College. 

 He had a strong barrel pump, and carried the nozzle at the end of a 

 long rubber tube, with a bamboo extension pole, up into the center of 

 the trees by climbing a ladder to the main crotch. From this point 

 the spray was thrown in all directions, and the tree was thoroughly 

 coated with the mixture in a minimum of time. 



The Gypsy Moth Commission, in their earlier spraying work, sent 

 their large tank carts through the streets, stopping at each tree and 

 sending one or more men with hose and extension poles into it, thus 

 covering hundreds of large trees in a single day. If steam sprayers 

 are used (and the town or city fire engines can be and have been used 

 to excellent advantage in this way), the necessity for climbing the 

 trees may be largely avoided. By means of multiple-discharge hose 

 both sides of a tree, or even of two trees, may be sprayed at once, 

 and the extent of territory that may be covered in a day is surprising. 

 The elm trees in a small park may be treated economically and with- 

 out much difficulty by two or three men with a handcart tank. This 

 method has been adopted on the large grounds of the Department of 

 Agriculture with absolute success. 



The writer's experience at Washington leads to the conclusion that 

 it is important to spray trees once just after the buds have burst. 

 This spraying is directed against the overwintered beetles. If a large 

 proportion of these beetles can be destroyed by poisoning the leaves 

 which they eat, not only will a great deal of leaf perforation by the 

 beetles themselves be prevented, but the number of eggs laid will be 

 very greatly lessened. A second spraying should be conducted two 

 weeks later. This is directed against the larvae, the majority of which 

 will perhaps have hatched by that time or soon after. A third spray- 

 ing, and even a fourth, or under exceptional circumstances a fifth, 

 may be required if it is considered necessary to keep the trees fresh 

 and green, and particularly if the earlier sprayings have been followed 

 b\ raiirs, as is apt to be the case in the earlier part of the season. In 

 Bridgeport, Conn., where only a part of the trees are sprayed and 

 these by private enterprise, an even greater number of operations 

 have been found desirable. Three thorough sprayings of all the trees 

 in a given precinct will probably be as much as will be required, 

 especially if this be done year after year and some pains be taken to 

 destroy such of the larva? as may successfully develop and descend 

 for transformation. Even two sprayings, covering all the elms of a 

 city or town, will be well worth the expense. 



