354 REPORT OF THE COMMISSIONERS OF 



Elm Leaf beetle. 



Galerticella luteola Muller. 



This imported insect is in all probability responsible for more ruined elm trees 

 in the Hudson river valley than all other destructive agencies combined. The above 

 is a sweeping assertion, but a careful examination of conditions in various cities and 

 villages compels one to accept this conclusion as very close to the truth. The 

 extensive and vigorous means employed in controlling this pest in Albany and Troy, 

 N. Y., have mitigated the injury very materially and have demonstrated the possi- 

 bility of keeping the insect under control. The results in Albany are evident to any 

 observer, for instead of a large proportion of the elms having their leaves skeleton- 

 ized and brown in midsummer, as was the rule in 1896 and 1897, the effects of the 

 work of this pest are seen only here and there where trees have not been thoroughly 

 sprayed or else entirely neglected. These more local injuries show that the pest is 

 still here with unabated vigor and warrants the assumption that the improved con- 

 dition of the elms is due largely to the extensive spraying operations. 



Distribution. This beetle is common over a large part of Europe but it is injuri- 

 ous only in the southern portions of Germany and France and in Italy and Austria. 

 It probably established itself in this country about 1834, as it was very injurious to 

 elms in Baltimore in 1838. It is now found from Charlotte, N. C, to north of Salem, 

 Mass., and as far west as Kentucky, at least. The progress of this insect up the 

 Hudson river valley is interesting to follow, indicating as it does, the distribution of 

 the beetle along the lines of travel. The pest was abundant and destructive at New- 

 burg in 1879, I2 y ears later it was reported from Poughkeepsie, in 1890 from Hud- 

 son, in 1 891 from New Baltimore, in 1892 it was known in Albany and Troy, in 1896 

 it was taken at Mechanicville, and in 1900 it was located at Schuylerville and Salem. 

 It occurred in numbers at Hoosick Falls in 1899 and has also been taken at Oswego, 

 Hastings and Rochester. Prof. M. H. Beckwith reports its presence in numbers at 

 Elmira, Chemung county. The distribution of the species in this state may be 

 given briefly as follows: The Hudson river valley north to at least Schuylerville 

 and Salem and with several colonies in the southern and western central portion of the 

 state. These latter are of great economic importance as they indicate that this 

 species can exist in that section of the state and give rise to the fear that in time it 

 may become as destructive there as it now is in the Hudson river valley. The pres- 

 ence of this pest in these localities should be regarded as a warning and measures 

 should be taken by local authorities to prevent the possibility of extensive ravages. 



