THE PAINTED HICKORY BORER 177 



borer (Clytus robiniae) was a common borer in the trunks and limbs of 

 black walnut, and was also quite destructive to hickory hop poles and 

 firewood. 



Kirkpatrick (1856) seems to have been the first to realize that the 

 locust and hickory borers were two distinct species. He stated that two 

 species of Clytus were found in Ohio, one the locust borer and the other 

 the hickory borer. Furthermore, he said that Cyltus pictus was found 

 only in hickory wood, where it generally bored parallel with the grain, 

 causing powder post. He gave brief data concerning the time of pupation 

 and the emergence of the adult. However, he says that he never found 

 the adult depositing eggs in wood cut more than a year, even when it 

 had no other wood in which to deposit the eggs. 



Horn (1863), referring to the hickory borer under the name Arhopalus 

 pictus Drury, described the character of the larval galleries in hickory 

 wood. 



The next reference to the hickory borer was made by Walsh (1864). 

 Discussing the spread of the locust borer westward, he mentioned that as 

 much as six years previous to the arrival of that insect he had split an 

 adult male Clytus pictus out of a stick of hickory in Rock Island, Illinois, 

 and that in the course of the next two or three years, he had found two 

 more specimens in the same neighborhood. He believed this was proof 

 that the locust and hickory species were distinct, for the hickory species 

 had evidently been in existence in Illinois all the time, but had fed on 

 hickory and walnut quite unnoticed until the arrival of the locust borer. 

 He also added that Professor Sheldon, of Davenport, Iowa, had told him 

 that for many years back he had repeatedly discovered Clytus pictus in 

 hickory wood, and that, so far as he was aware, the locusts of Davenport 

 had not been attacked by this insect. 



Later, Walsh (1864) definitely showed, by anatomical characters, that 

 the locust and the hickory species were distinct. In studying the adults 

 of both species, he found that there were quite remarkable differences 

 in the males, but none in the females. These differences in the males 

 he tabulated as follows: 



Hickory feeding "b Locust feeding "b 



1. Antennae, when relaxed and laid i. Antennae, when relaxed and laid 

 close and straight along the back, reaching close and straight along the back even in 

 beyond the tip of the elytra by the whole the specimen which has the longest ones, 

 length of the terminal joint (n). not attaining the tip of the elytra by a 



space equal in length to the two terminal 

 joints (10 and n). 



2. Antennae from % more robust to 2. Antennae much less robust, except 

 twice as robust, especially towards the the few last joints, and less tapered from 

 base. base to tip. 



