356 



REPORT OF THE COMMISSIONERS OF 



The lateral yellow stripe includes a row of prominent tubercles with dark tips bear- 

 ing short hairs of the same color. The under surface is yellowish. 



The pupa is a bright orange yellow, about \ of an inch long, and with a very con- 

 vex dorsal surface which bears transverse rows of stout, inconspicuous hairs (Plate i, 

 figure 4). 



Fig. 1. — Leaf showing holes eaten by elm leaf beetle. Fig. 2. — Work of elm leaf beetle grubs. 



Life history. The transformations of this insect are so rapid that a man must 

 know what to expect or in fighting the pest he will accomplish practically nothing, 

 because a substance effective against the beetles or grubs may not kill the pups, and, 

 after the larvae have begun to descend the trees, may be of no value. 



■ The winter is passed by the beetles in attics, sheds, outhouses and in other shel- 

 tered places. With the advent of warm weather in the spring, they emerge from 

 their retreats and may be found on the walks during the sunny portion of the day 

 or upon the windows of houses trying to escape. The last of April or early in May, 

 with the appearance of the elm leaves, the beetles fly into the trees and eat irregu- 

 lar holes in the foliage (Figure 1 and plate 1, figure 9). Some time is occupied in 

 feeding before the deposition of eggs begin, a process which may continue over four 

 and possibly for five or six weeks. These prolific beetles consume a large amount 

 of foliage during this time, depositing clusters of three to 26 or more eggs every 



