41 



I am inclined to think tbat in towns of higher elevation and which lie 

 decidedl}' outside of the upper austral life zone it will not assume the 

 serious aspect that it takes on within this zone. 



I have spoken only of its occurrence in cities. i)artly because its 

 importance in cities is so very great, and also because it practically 

 does not occur outside of cities or towns where elms are planted in some 

 number and rather close proximity. In Washington, where the insect 

 has been known for more than forty j'ears, it does not occur upon elms 

 growing along neighboring country roads or even in immediate suburbs. 

 I have noticed the same thing in Xew England. The plain inference is 

 that the insect does not spread from town to town by using country 

 trees as stepi)ing- stones. The great means of transport here must be 

 the railroads. The beetles developing on trees near railway stations, 

 searching in late summer for hibernating places, can certainly find no 

 more convenient places than freight or box cars. It is i^robably mainly 

 in this way that it has spread up this valley, and in this way it has 

 probably been carried manj^ times into regions where the climatic con- 

 ditions are such that it has not succeeded in perpetuating itself. 



That the elm leaf-beetle should be a more serious insect i^lague in 

 New England than it is farther south seems rather a strange fact, aside 

 from the somewhat greater x^opularity of the elm as a shade tree Xorth 

 than South. 



It is, however, a much more serious enemy here, and this is due to 

 the comparative shortness of the season. I have seen handsome old 

 trees in Stratford, Conn., absolutely killed after three years* consecu- 

 tive and complete defoliation. The recuperative powers of the more 

 southern elms lie in their ability to throw out a second and even a third 

 crop of leaves, with rains coming at the right time. It results from 

 this fact that trees defoliated forty years in succession are still appar- 

 ently healthy, although they have not made much growth — almost none 

 at all. With rains at the right time, in late July and early August, and 

 abundant rains they must be, Connecticut trees will put out a second 

 crop of leaves and will recover to a considerable extent. With a 

 drought thrcmgh August, liowever, extending either side a little into 

 July and September, the trees remain without leaf surface the whole 

 year, and are practically asphyxiated in a couple of seasons. The 

 Stratford elms were killed in this way, and if we are to believe the 

 newspaper accounts, a number of trees on the Princeton College campus 

 have died this year from the sanu^ cause. 



The unsightly appearance of the defoliated trees, therefore, the non- 

 fulfillment of their function as shade makers, and their possible, if not 

 probable, early death make the destruction of the elm leaf-beetle in 

 Springfield and other Connecticut Iviver Valley towns a matter of very 

 great importance. 



Of all the remedies which have been proposed none is so satisfactory 

 as thorough and careful spraying with some arsenical mixture. No 



