Hickory Trees Threatened with Destruction- By J. J. Levison, 



A NEW INSECT PEST OF OUR SHADE TREES — PROMPT AND DRASTIC MEASURES NEEDED 

 TO SAVE THE TREES BEFORE THERE IS DANGER OF ATTACK BY THE HICKORY BARK BORER 



Arboriculturist 

 Brooklyn, NY. 

 Park Department 



DID your hickories show wilted leaves 

 and many dead twigs in June, 

 July and August? You lost your chest- 

 nut trees; and discovered the fact when it 

 was too late. You may lose your hickories 

 just as fast. The hickories about New 

 York, on Long Island (in the neighborhood 

 of Flushing, Douglaston, Great Neck), 

 are badly infested with the hickory bark 

 borer (Scolytus quadrispinosus) and hun- 

 dreds of trees have already been killed 

 by this insect. Trees in the Bronx, in 

 Flatbush and other places in the vicinity of 

 Greater New York are also infested, 

 and nothing but prompt execution of dras- 

 tic measures over the entire infested area 

 will save the thousands of remaining 

 hickories in this region. There are 16,000 

 hickories standing in Forest Park, Ja- 

 maica, still free from insect infestation 

 and there are thousands of others filling 

 the woodlands on Long Island and along 

 the Hudson. Can we afford to lose them? 



THE REMEDY 



The insects spend most of their lives 

 boring under the bark and are therefore 

 inaccessible for treatment except to cut 

 the infested trees down and burn the bark. 

 If a tree shows signs of infestation, though 

 partially alive, it is just as well to cut the 

 tree down, because it is sure to die in a 

 short time and leaving it standing would 

 only harbor many of the insects that will 

 afterward emerge to other trees. In case 

 of valuable specimens, it may be well to 

 remove and burn all infested branches. 



During the middle of May, the beetles 

 gnaw in the leaf stalks and it may then 

 be well to spray the 

 petioles of the leaves 

 with arsenate of 

 lead,but this method 

 can but little be de- 

 pended on and the 

 salvation of the 

 hickory really lies in 

 the rapid and abso- 

 lute destruction of 

 all infested speci- 

 mens. 



The writer has 

 now been fighting 

 this insect in the 

 parks of Brooklyn 

 for the past four 

 years. Every known 

 method of treatment 

 has been tried and 

 the remedy sug- 

 gested is the result 

 of this experience. 



The hickory wood 

 is heavy, hard and 

 strong and that of 

 the removed trees 



would be sufficiently sound to be suitable 

 in the manufacture of agricultural imple- 

 ments, carriages and wagons, for fuel, 

 telephone poles, ties or posts. 



Bark of mocker-nut hickory after the hickory 

 bark borer has emerged. Fungus follows the bor- 

 er's attack 



Workings of the borer. The first specimen shows the holes on the surface of the bark: 

 third specimens show the galleries formed by the borers 



109 



In 1903, a similar infestation occurred 

 at Belle Isle Park in Detroit, Mich. All 

 the hickory trees there were threatened 

 with destruction and only a timely cutting 

 down of the infested ones saved the rest. 

 The felled trees were sold and covered the 

 expense of cutting. 



THE INSECT AND HOW TO TELL ITS PRESENCE 



The mature insect is a very small brown 

 or black beetle. It forms longitudinal 

 burrows in the outer sapwood immediately 

 under the bark and from these burrows 

 emanate side galleries formed later by their 

 legless grubs. These grubs are also very 

 small, about one-fourth inch in length, 

 white with -brownish heads and powerful 

 dark colored jaws. The insects are very 

 prolific and within the same summer a 

 tree may be infested and killed. 



The presence of the insect can be de- 

 tected by the small holes in the bark of the 

 tree and the fine sawdust which is ejected 

 from these holes when the insects are active. 

 These holes, however, will not be notice- 

 able until the insect has completed its 

 transformations. In summer, the infested 

 trees show wilted leaves and many dead 

 twigs. Holes in the base of the petioles 

 of these leaves are also sure signs of the 

 workings of the insect. 



The hickory bark borer is an old enemy 

 in this country but has never before 

 been serious enough in the vicinity of 

 New York to cause special comment. 

 Now it is serious enough to cause 

 alarm. It was observed as early as 1867 

 and has since then been studied by 

 entomologists in many parts of the coun- 

 try. The writer 

 first observed its 

 presence on Long 

 Island at Prospect 

 Park in 1906. He 

 then obtained the 

 personal assistance 

 of Doctor E. P. Felt, 

 the State Entomolo- 

 gist, and has since 

 been making efforts 

 to check its rav- 

 ages. But so long as 

 there remain in- 

 fested trees on pri- 

 vate grounds in the 

 vicinity, the neigh- 

 boring good trees of 

 this species are in 

 danger of reinfesta- 

 tion and something 

 must be done to 

 secure cooperation 

 to eradicate the pest 

 from the whole in- 

 fested area at one 

 time. 



the second and 



