53 



time during the seas^on a siii.i?le larva or pupa upon its roof, although 

 fallen leaves in corners offered convenient resting i)laces for them. Nor 

 in the hours that I have i)assed under the elms in my study of the insect 

 have I seen one of the larvie upon my clothing or known it to occur on 

 others. 



Preference for different species of elms. — The preference shown by the 

 ehn leaf-beetle for certain species of elms has often been stated by those 

 who have written upon it. While all agree in the statement that the 

 European elms are more infested by it than our native ones, yet there 

 is conflicting testimony iu regard to the liability to attack of the Ameri- 

 can elm ( Vlmus aniericana). Dr. Riley has stated of it iu Bulletin Xo. 

 6 of the Division of Entomology (1885), "This species is practically 

 free from the ravages of the beetle." In Circular Xo. 8 (May, 1805) 

 of the same division Mr. Marlatthas written: "The American species, 

 TJhniis amerieanaj is notably exempt," but adding this qualification: 

 "All species of elms, however, are attacked more or less, and iii the 

 absence of sufficient foliage of the favorite varieties the injury to less, 

 palatable sorts becomes almost equally marked."* 



Decided preference for the English elm. — The decided i)reference of 

 the beetle for the TJlmus campestris has been strikingly shown during 

 its presence in Albany. A number of trees of this species have died 

 and are being cut 'down in this the fourth year of their attack, while 

 others — notably the row previously referred to as opposite my resi- 

 dence — will unquestionably share the same fate the coming year, unless 

 conditions should prove unfavorable to the beetles' multiplication. 

 None of the Scotch elms, so far as I have discovered, have been killed, 

 and although the foliage of some of the smaller trees has been about 

 one-half destroyed, there is little probability of tlieir succumbing to 

 the attack, unless they should finally yield to partial defoliation through 

 several succeeding years. Just across the street from the doomed elms, 

 above mentioned is a large American elm (their branches almost inter- 

 mingling) which seems to be entirely free from the insect. Kot a larvai 

 has been detected upon its trunk or indications of it upon the foliage 

 when its branches were carefully examined from the housetop. A_ 

 quarter of a mile from this point are the Capitol and the Boys' Acad- 

 emy parks, in which all of the trees, according to the State botanistv 

 are American elms. No trace of the insect was found in these parks, 

 when search was made for it during the last week of August. These^ 

 three species of elms are the only ones which have been identitied by 

 me in the infested section of Albany. 



The slow spread of the insect. — Perhaps no better illustration of the^ 

 slow distribution of this insect, when left to its natural spread and 

 unaided by facilities for transportation by railroad or boat, can be 



*In the discussion that followed this pa])cr it was stated that tho VJmns americana 

 under certain circumstances had heeu kuowu to be quite as badly injured by the 

 insect as the European species. 



