"1'HE BRONZE BIRCH BORER 73 



the common white birches in Buffalo's parks were injuriously infested by a 

 borer. By 1898, several trees had been killed, the cut-leaved varieties 

 also were being attacked, and the culprit was found to be the bronze 

 birch borer. I saw in Delaware Avenue Park in Buffalo on May n. i8gg, at 

 least one hundred magnificent white birches, some of them veritable monarchs 

 nearly two feet in diameter at the base, all dying from the work of this borer. 

 In August of the same year, Mr. Adams reported that from one spot in one 

 of Buffalo's parks he could see fourteen black and yellow birches, but twelve 

 of them were dead, all killed by this borer. Chamberlain reported in 1900, 

 (Scientific American, Vol, 82, p. 42), that the result of the work of this insect 

 is that " nine-tenths of Buffalo's white birches are either dead or dying and the 

 rest will soon follow. Several hundred have died, including about 50 in Forest 

 Lawn Cemetery the present season. Even the dead trees were not burned, 

 and the pests were allowed to multiply at will." 



I have seen over half of the white birches on the Cornell University 

 Campus and many of those scattered about Ithaca's lawns killed by the insect 

 within the past three or four years. And unless the vigorous, prompt, and 

 judicious measures now being enforced on the Campus are carried out through- 

 out the city, Ithaca's white birches will soon be dead monuments to the 

 industry and destrucliveness of this little enemy. 



FOOD- PLANTS OR KINDS OF TREES ATTACKED 



This insect seems to confine its work almost entirely to birch trees. The 

 only exception yet recorded is discussed on page 72 where it was found mak- 

 ing gall-like swellings on a willow. The European white birch (Bttula alba) 

 and its cut-leaved weeping variety (pendu/a laciniata} have suffered most 

 from its ravages. In the outbreak in Buffalo, the former or alba was first 

 attacked, the infestation then extending to the cut-leaved variety. But I have 

 seen a case in Ithaca, where a cut-leaved birch was killed before a tree of the 

 whole-leaved form only a rod or two distant showed any signs of being infested. 



Several trees of the American black (J3etu!a lento} and the yellow (Betula 

 luted) birch have been killed by the insect in Buffalo, and it is also recorded 

 as attacking the paper or canoe birch (Betula papyriferd] . 



However, there is no record of any kinds of birches having been killed 

 by the insect in forests or woodlands. It seems to have confined its destruct- 

 ive work to the more valuable individuals and groups of these beautiful trees 

 set in parks and private lawns. 



The beetles have been taken on poplars cut and piled by the roadside, 

 on poplar sprouts and trunks, and on willow, but there is no evidence that the 

 insect was breeding in poplar. Larsen put a number of the beetles in a cage 

 and supplied them with fresh leaves. " When only birch leaves were supplied 

 they fed very sparingly. Some elm leaves were then put in with the birch and 

 they fed greedily upon these. This led to further experiment and various 

 sorts of lea?ves were used. They fed upon almost any leaf of soft texture. 

 But their favorite food was willow, poplar and aspen leaves with preference 



