11 



enough back to include from two to four or five leaves, and this 

 amputated portion is free from egg or larva. But I now began 

 to find, scattered under the infested trees, pieces of twigs which 

 had been cut off at both ends, and those freshly dropped con- 

 tained in most cases either an egg or a newly hatched larva, 

 while in the older, withered ones there was more often a very 

 young larva, dead. As the season of oviposition advanced, these 

 secondary amputations, repeated perhaps five or six times on 

 the same twig, became more numerous, and an examination of the 

 trees disclosed the fact that nearly every twig contained at least 

 one egg or larva, and that some of them contained several. For 

 those females that had yet to oviposit, there were no twigs not 

 preoccupied, and fully five per cent, of the amputated pieces on 

 the ground contained a larva or an egg. It became clear that 

 the mortality resulting from this repeated oviposition and am- 

 putation was greater than that from all other causes combined. 

 The beetles appear to feed but little, and then only on the 

 leaf veins, as shown in Fig. 5, Plate I., and at the extreme right 

 of the colored plate. Neither Mr. Titus nor myself found them 

 feeding on any other part of the leaf, or any indication of their 

 having done so, even when confined in breeding-cages. 



FOOD PLANTS. 



. It would seem from the information thus far obtained, that 

 this species confines itself strictly to the American elm. While 

 the beetles will, if confined on other plants exclusively, feed 

 sparingly on the leaves, they will not oviposit in the twigs, but 

 if removed and placed on elm, they will proceed to deposit their 

 eggs. Adults of both sexes confined on raspberry May 20, were 

 all dead by May 29, having in the mean time shown no inclina- 

 tion whatever to oviposit, though the sexes were observed in the 

 act of pairing. The same was true of those confined on Cornus; 

 but when removed, these females oviposited in elm. These state- 

 ments are taken from Mr. Titus's notes, and my own experi- 

 ments simply duplicated these results. Though I found Oberea 

 larvae in other kinds of trees in the parks at Decatur, I am con- 

 fident that these belonged to another species, probably Oberea 



