ELM LEAF BEETLE IN NEW YORK STATE 27 



oughly sprayed it may not be necessary to treat them again for 

 two years. 



The second spraying should occur at the time the young are 

 beginning to hatch, which in this latitude is about the first week 

 in June. The poison should be applied to the under surface of 

 the leaves. This is because the larvae feed only very excep- 

 tionally on the upper surface of the foliage or even break the 

 upper epidermis. Consequently it is impossible to poison them 

 unless the insecticide be thrown on the under surface. The 

 larvae succumb to the poison more readily than the beetles and 

 it is therefore not necessary to use so concentrated a mixture 

 in the later sprayings. 



The necessity for subsequent sprayings depends largely on 

 the manner in which the previous work has been done. Much 

 depends on the man who holds the nozzle, even though he be 

 under the eye of one who understands the business. The mix- 

 ture should be applied evenly in a rather fine spray and so far 

 as possible to every leaf. If the poison be applied thoroughly 

 and at the right time, two sprayings should be ample to keep 

 the beetle under control. Otherwise it may be necessary to 

 spray for the second and even the third brood. The proper 

 time for later arsenical sprayings must be determined by 

 observation. The spraying for the second brood should be done 

 in Albany and Troy about the latter half of July. 



A PALLIATIVE MEASURES 



It frequently occurs that for some reason spraying with 

 poison can not be resorted to readily. The habits of this insect 

 are such that at certain times large numbers can be destroyed 

 with little labor, as has been pointed out year after year. But 

 it is well to understand that such a measure is not a remedy 

 in the true sense of the word; it is simply a palliative. Every- 

 one interested in the welfare of his shade trees should at least 

 destroy tlie thousands of larvae and pui)ae on the trunks or 

 around the base of infested elms. If the base of the trees, their 

 surroundings and other adjac(^ni shelters be thoroughly 

 drenched with boiling water or si)rMye(l with kerosene, kero 



