Ninth Report of the State Entomologist 429 



ward to heal the wound and a vigorous flow of sap took place, many of 

 the larvae near it were killed, the bark that had not entirely been 

 undermined was consolidated, and the health of the tree improved." 



For a long period of years the elm has been remarkably free from 

 insect attack, but now it is struggling for existence against four 

 insect destroyers, so pernicious in their operations that we are almost 

 compelled to look upon it as a doomed tree. The Zeuzera is robbing 

 it of its beautifully branching top ; the elm-leaf beetle is defoliating it 

 and rendering it in midsummer useless for shade; the caterpillars of 

 the white-marked tussock-moth ( Orgyia leucostigma) are skeletonizing 

 its leaves and arresting terminal growth by amputating the ends of the 

 twigs and strewing them over the ground; and lastly, the three- 

 toothed Saperda — the most dangerous of all — is running its mines 

 through sapwood and liber so closely and tortuously that the death of 

 the tree is the inevitable result. 



It is sincerely to be lioped that should the suggestions above made 

 for staying the ravages of the last named insect not prove to be prac- 

 ticable, other means may be found, so eflicient and so simple as to lead 

 to their general use by individuals and by city authorities; and that 

 the steady progress northward and westward over the State of the two 

 other elm destroyers — the Zeuzera borer and the elm-leaf beetle — 

 may be stayed, and the most beautiful and serviceable of our shade 

 trees be spared to us and to coming generations. 



Experiment Station Pctbltcations. 



The work of the Experiment Stations during the j)ast year has 

 developed results which are of considerable value to the members of 

 this society. I will briefly refer to a few of the studies, citing the 

 bulletins where they are more fully detailed, in order that those who 

 so desire may make application for them to the several stations, and 

 procure copies before the editions shall be exhausted. 



The Pear Tree Psylla. — Mention has been made of the remarkable 

 cessation of the injuries during the past year of the pear-tree Psylla in 

 the Hudson river valley. This insect is not confined to the eastern 

 part of the State of New York and portions of the Eastern States 

 adjoining, but it also occurs in Central and Western New York, — not as 

 yet in great abundance, but the pear orchards are at any time liable to 

 an outbreak of it. 



A careful study of the insect has been made at Cornell University by 

 Mr. M. V. Slingerland, audits results published in an illustrated bulletin 

 of 28 pages, being Bulletin 44, October, 1892, of the University Agri- 



