78 REPORT OF THE STATE ENTOMOLOGIST I92I 



pains to throw the insecticide upon the under surface of the leaves. 

 Subsequent information suggests that the insect may have been 

 completely exterminated by unusually thorough spraying. 



Elm leaf beetle (Galerucella luteola Mull.) . The 

 somewhat general systematic spraying for the control of this pest 

 has resulted in a very great reduction in its numbers and compara- 

 tively slight injury particularly in the cities of Albany and Troy, 

 though the fact should not be overlooked that during the last few 

 years there has been comparatively slight injury in some adjacent 

 villages where there has been no spraying of any moment. 



Personal examinations and reports in 1919 indicate local and in 

 some instances rather severe injury by this insect in the city of 

 Johnstown and the villages of Canajoharie and Hoosick Falls. Very 

 similar conditions obtained at nearby Bennington, Vt., and there 

 was serious injury in portions of Pittsfield, Mass. 



The most effective method of controlling this pest is by early and 

 thorough spraying with arsenate of lead, using about 3 or 4 pounds 

 of the paste to 50 gallons of water. The treatment just as the 

 leaves are beginning to expand and while the beetles are feeding is 

 most effective since a very large proportion of the insects succumb 

 before eggs are deposited, provided there is thorough work. 

 Another excellent time is just as the leaves are nearly developed, 

 namely the first or second week in June for the latitude of Albany, 

 and then special pains must be taken to throw the poison on the 

 under side of the leaves, since the grubs feed only on the lower 

 surface and this treatment is directed against them rather than the 

 parent beetles. 



Bronze birch borer (Agrilus anxius Gory) . An exami- 

 nation July 30, 1919, of trees in Washington Park, Albany, showed 

 that one large white birch tree, with a trunk diameter of approxi- 

 mately 15 inches, leaved out this spring and later most of the foliage 

 died. Numerous borings of the pest were found in the inner bark 

 of the trunk of the tree, the only external sign being a moderate 

 number of oval holes in the bark. There were also some evidences, 

 though by no means abundant, of the work of this borer in the 

 larger limbs and to an even less extent in the smaller limbs. It was 

 evident that the tree had been girdled by the operations of this pest 

 last year and had strength enough to develop a crop of leaves, 

 though not to maintain them the following season. 



The unhealthy condition of the tree was evidenced by the presence 

 of the pigeon tremex on the limbs and engaged in ovipositing. 



