The European Elm Scale 15 



glossy often betray the presence of the European Elm Scale. On the 

 date mentioned I took from a tree which seemed only slightly infested 

 ten leaves on which there were just one thousand larvae, 618 of which 

 were living. Both dead and living were of all sizes, from those just 

 hatched to some as large as the winter larvae. On October 18th, 1906, 

 larvae were still abundant on leaves recently fallen from infested 

 branches, especially along the mid-rib on the underside. A few were 

 discovered in slight recesses along the mid-rib on the upper surface. 

 Leaves which had fallen some days previously and which had since 

 been lying on the lawn bore very few larvae. On October 24th, 1906, 

 larvae were still numerous on leaves which had fallen before the frost. 

 On November 1st, after a heavy frost, one or two could still be found 

 occasionally on fallen leaves, very few on the leaves which remained 

 on the tree. 



On the trunk of an American elm near at hand I found large 

 numbers of larvae clinging to the trunk within one foot of the ground. 

 They were present in a similar position on the trunk of an English 

 elm growing near at hand. The unusual position of these clustered 

 larvae leads me to infer that they had fallen to the lawn on the falling 

 leaves, had abandoned them, and taken up positions on the trunks of 

 the adjacent elms. 



THE NATUBE OF THE INFESTED TREES 



The Cork Elm, (English Elm, Vlmus cqmpestris, Smith). 



This is the favorite shade tree in western Nevada and we have used 

 the name by which it is commonly known in this region, although 

 many of these elms are almost wholly devoid of cork, while on others 

 all of the smaller limbs are shaggy with it in thin longitudinal plates 

 which radiate from the axis of the branch in all directions. The habit 

 of growth is broader and more spreading than that of the American 

 elm. The trunk is comparatively short and stocky, it divides into 

 from three to ten large branches which in turn divide repeatedly and 

 bear a dense mass of deep green foliage which lasts from May until 

 November, giving a most welcome shade in this climate of dry summer 

 heat and intense sunlight. In moist soil the English elm has the bad 

 habit of sending up little thickets of sprouts and suckers about the 

 roots. Thousands of these elms have been planted along the residence 

 streets and in parks in Reno and Carson City ; they are not so common 

 as yet in the country districts. In western Nevada they are young 

 trees of necessity, few of which are over forty feet in height, and 

 though vigorous and hardy they are very susceptible to the attacks 

 of the European Elm Scale. Plate XIV. 



