A REPOR1 UPON THE CONDITION OF THE SHADE 

 TREES OF THE CITY OF MOUNT VERNON, N. Y. 



The Entomologist, under the guidance of Alderman Whitmore 

 and Commissioner of Public Works Harlow, examined the shade 

 trees of Mount Vernon Tuesday afternoon, June 20, 1911. It 

 was obviously impossible to make a careful examination of all 

 the injured trees in the city. Our investigations were therefore 

 limited to what were considered typical localities. At the outset 

 we were informed that some 2136 trees were sprayed last spring, 

 largely for the purpose of controlling the false maple scale. 1 

 Many of these, mostly hard maples, show signs of severe injury 

 from one cause or another. 



An examination of the trees disclosed the fact that the leop- 

 ard moth 2 is generally present in the city and, furthermore, that 

 it is liable to cause, if allowed to breed unrestricted, serious 

 injuries within a few years. We observed no maples so 

 badly infested with this insect as to justify holding the pest 

 responsible for the recent and sudden death of individual trees, 

 or even of good sized limbs, though we did find certain trees, 

 mostly soft maples, which were. rather badly infested by this 

 species. 



Our investigations also showed that a " pin-hole " borer 3 or 

 " Ambrosia beetle " is generally present on the dead and dying 

 trees. This insect is just entering the maples, attracted by their 

 unhealthy condition and therefore can not have a causative rela- 

 tion to the present sad state of many hard maples in Mount 

 Vernon. 



There was also found on a number of these trees, a moderate 

 sized, reddish-brown, yellow-marked beetle, 4 which, like the 

 "pin-hole" borer, is an inhabitant of diseased or dying trees. 



At Park avenue and East Sibley street, near the church, there 

 were fifteen out of about twenty hard maples with at least the 

 lower limbs seriously affected, a few of the smaller having 

 practically all the foliage destroyed. The type of injury observed 

 here was limited to trees marked or recorded as having been 

 sprayed. We were informed that this was done in March. 



1 P h e n a c o c c u s accricola King. 



2 Zeuzera pyrin a Linn. 



3 X y 1 o t c r u s sp. 



4 Ncoclytus erythrocephalus Fabr. 



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