ELM LEAF BEETLE. 819 



When first hatched, the larva is dark or nearly black, covered 

 with tubercles bearing black hairs. As the larva increases in 

 size it molts several times and on becoming full grown is about 

 one-half inch long, dull yellow in color, with a pair of longi- 

 tudinal black stripes along the back. . Head, legs, lateral tubercles 

 and two rows of small tubercles between the dorsal stripes are 

 black. The tubercles also bear black hairs. 



The pupa is about one- fourth inch in length and bright orange 

 yellow in color, with black hairs or spines. It is not enclosed in 

 an earthen shell to protect it, but is found at the base of the tree 

 perfectly naked and wholly unprotected. 



The adult beetle is light yellow in color when it first emerges, 

 but soon takes on a duller hue, and finally becomes a dull olive 

 green. An indistinct black stripe extends from the base to the 

 extremity of each wing-cover just inside of the margin. Small 

 black spots or markings on the pronotum of the thorax vary 

 greatly in size and shape. Legs and antennse are yellow. 



Eggs, larvae, pupae and adults are shown on Plate LV. 



EFFECT UPON THE TREES. 



It has previously been mentioned that the adult beetles do 

 more or less feeding, always eating holes entirely through the 

 leaves, as is shown on Plate LIVb. This of course injures the 

 tree, but is much less serious than the damage caused by the 

 larvae, which eat away the under surface of the leaves. The larvae 

 are always more abundant than the adult beetles, and are more 

 voracious in their feeding habits. The worst infested trees 

 usually drop their leaves in Connecticut about the middle of July. 

 If this happens, and is followed by a rainy season, new leaves 

 will be put out, but in a season of a protracted drought the trees 

 may fail to put forth new leaves. In either case the tree is 

 undoubtedly weakened, and often seriously so. Sometimes the 

 second crop of leaves is devoured by the second generation of 

 beetles, but in Connecticut the white fungus mentioned in another 

 part of this bulletin is apt to serve as an important check to the 

 beetle in a wet season. Two complete defoliations, one succeed- 

 ing the other, usually kill a tree. Usually, however, the defolia- 

 tion is not quite complete, and the trees continue to exist in a 

 greatly weakened and devitalized condition. In the cities and 



