10 



the Alleghany and Blue Kidge mountains, it will spread unchecked 

 through Ohio, Indiana, Kentucljy,Tennessee, and other Western States.' 



Food plants.^^o food plants other than elms are known. The 

 common English elm ( Uhnus campestrls) is its favorite food, and the 

 gardener's variety, the so-called Camperdown, or weeping elm, is 

 attacked with equal avidity. The American, or white, elm ( U. arneri- 

 cana) ranks next among the favored species, with U. montana, U. 

 suherosa, U.fla/va, U. racemosa, and U. alata in about the order named. 

 No variety seems absolutely exempt. In the presence of JJ. campestris 

 other elms are seldom seriously injured. Where campestris is absent, 

 or where a single tree of campestris is surrounded by many American 

 elms, the latter become seriously attacked.^ 



Life history and habits.— The elm leaf-beetle passes the winter in 

 the adult, or beetle, condition in cracks in fences or telegraph poles, 

 under the loose bark of trees, inside window blinds in unoccupied 

 houses, in barns, and, in fact, wherever it can secure shelter. As soon 

 as the buds of the trees begin to swell in the spring, the beetles issue 

 from their winter quarters and mate, and as soon as the buds burst 

 they begin to feed upon the leaflets. 



This feeding is continued by the beetles until the leaves are fairly 

 well grown, and during the latter part of this feeding period the 

 females are engaged in laying their eggs. The eggs (fig. 3, c) are 

 placed on the lower sides of the leaves, in vertical clusters of 5 to 20 

 or more, arranged in two or three irregular rows. They are elongate 

 oval in shape, tapering to a rather obtuse point, orange yellow in color, 

 and the surface is covered with beautiful hexagonal reticulations. 

 These reticulations, however, can be seen only with a high magnifyit g 

 power. 



The egg state lasts about a week. The larvse (fig. 3, d) as soon as 

 hatched feed on the under surface of the leaf, gradually skeletonizing 

 it. They reach full growth in from fifteen to twenty days, and then 

 either crawl down the trunk of the tree to the surface of the ground 

 or drop from the extremities of overhanging branches. At the sur- 

 face of the gtound they transform to naked, light orange-colored pupae 

 (fig. 3, g) a little over a quarter of an inch in length, and in this stage 

 they remain for from six to ten days, at the expiration of that time 

 transforming to beetles. The pupss will frequently be found collected 

 in masses at the surface of the ground in this way. On very large 

 trees with shaggy bark many larvre will transform to pupae under the 



bark scales, or on trees of the largest size they may descend the main 

 ~ 1 . 



1 Since this was written the writer has learned that this passage of the Blue Ridge 

 barrier has actually taken place during the past season. Mr. A. D. Hopkins, of the 

 West Virginia Agricultural Experiment Station, has found that this insect has estab- 

 lished itself at Elmgrove, in Ohio County, and at Wellsburg, in Brooke County, W. Va. 



2 The beetles rarely oviposit upon Zekova carpiniafolia ard Z. acuminata on the 

 Pepartment groundg at Washington, 



