through Ohio, Indiana, Kentucky, Tennessee, and other Western 

 States. 1 



Food plants. No food plants other than elms are known. The com- 

 mon English elm ( Ulmus campestris} is its favorite food, and the gar- 

 dener's variety, the so-called Oamperdown, or weeping elm, is attacked 

 with equal avidity. The American, or white, elm ( U. americana) ranks 

 next among the favored species, with U.montana, U.suberosa, TJ.flava, 

 U. racemosa, and U. alata in about the order named. No variety seems 

 absolutely exempt. In the presence of U. 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. 2 



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 magnifying power. 



The egg state lasts about a week. The Iarva3 (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 surface of 

 the ground they transform to naked, light orange-colored pupae (fig. 

 3, </), 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 trans- 

 forming to beetles. The pupre will frequently be found collected iii 

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

 with shaggy bark many larvre will transform to pup3 under the bark 

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



1 Since this was written the writer has learned that this passage of the Blue Rid^e 

 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 

 established itself at Elragrove, in Ohio County, and at Wellsburg, in Brooke County, 

 W.Va. 



2 The beetles rarely oviposit upon Zelcova carpiniafolia and Z. acuminata on the 

 Department grounds at Washington. 





