16 NEW YORK STATE MUSEUM 



crawl up and down the shag:gy bark. Occasionally their num- 

 bers are so great as to give a distinct character to the surface 

 they are moving over, presenting a peculiar grayish yellow mass 

 of motion enlivened here and there with an orange yellow pupa. 

 A few days later the pupae are more numerous on the trunk 

 and around the base of the tree and adjacent shelter, where 

 they may sometimes be found in golden layers nearly an inch 

 deep, interspersed here and there with a dark larva. Many 

 larvae do not descend the older trees but take refuge in the 

 crevices of the bark, or, if there are overhanging limbs, may 

 drop in numbers from the tips of the branches. Many are con- 

 tent to transform in the gutters, others seek shelter in the 

 crevices of the sidewalks and large numbers cross wide spaces 

 and pile themselves up against a wall or a fence or around any 

 sheltering bush or weed. 



SPECIES OF ELMS ATTACKED 



It will be observed in most localities that the American elm, 

 U 1 m u s a m e r i c a n a . is comparatively exempt from the 

 attacks of this insect. Sometimes the beetles will make their 

 way from adjacent European elms and seriously injure the 

 American species and, after they have once become established, 

 the but partially migratory habit of the beetle insures attack 

 for a few successive seasons at least. The English elm, 

 Ulmus campestris, and the Scotch elm, U 1 m u s m o n - 

 tana, usually suffer most seriously, while our native species 

 are but little affected. This was very noticeable in Troy and 

 Lansingburg. European elms are numerous in the former 

 place and the work of the elm leaf beetle is conspicuous over 

 the greater part of the city, but as one proceeds northward into 

 Lansingburg American elms abound almost to the exclusion of 

 the foreign species and evidences of the pest are comparatively 

 rare. Again, in 1895 the American elms of Albany showed very 

 little injury by the insect. The next year trees here and there 

 gave evidence of a serious attack and in 1897 a much larger 

 number of the American elms was seriously injured than in 

 the preceding year. The numerous American elms in Water- 



