INSECTS AFFECTING PARK AND WOODLAND TREES 93 



Locust borer 



Cyllenc robiniac Forst. 

 Irregular ugly scars oi)ening into burrows about ]i inch in diameter are very com- 

 mon on our native black locust. This is the work of a black beetle, less than ?i inch 

 long, very prettily marked with golden yellow. May be found in considerable numbers 

 in the fall on golden-rod. 



The work of this insect is very common on black locust trees in Xew 

 York State, and the beetle occurs in considerable numbers each year. The 

 species is such a pretty one that it is not infrequently submitted to the 

 entomologist with an inquiry as to its name and habits. Its depredations 

 are so serious in some sections of the .State as to mar the beauty of our 

 locust trees. Almost every row of any size may be recognized at a distance 

 by the large number of dead limbs projecting above the leafy branches, an 

 appearance which in most cases must be attributed to the work of this 

 borer. Its operations lower down, particularly in the case of small trees, 

 produce very unsightly scars which admit moisture and promote decay. 



Early history. This species was observed by Dr Harris in Massachu- 

 setts, who characterizes the pest as a most destructive insect. Dr Fitch, 

 in 1858, states that this borer is the greatest obstacle to the cultivation of 

 the locust tree with which the growers have to contend. He records an 

 instance in the city of Utica where one of the principal thoroughfares, 

 early planted with locusts, had been invaded by this borer, and the mag- 

 nificent trees either killed outright or totally ruined. He states that 

 Micheaux records this species as so destructive 50 years before that many 

 were prevented from planting the locust. Dr Fitch adds that heretofore, 

 this borer appeared to have been a pest in the older settled section of our 

 country and that no doubt in time it will become equally destructive in the 

 newer 'districts. He considers this a native species though some of the 

 earlier writers thought it was an introduced form. It was noticed by 

 MrS. S. Rathvon in 1861, who records this species as one of the most 

 common and destructive to this tree, and incidentally he confuses this insect 

 with the hickory- borer, C 1 y t u s p i c t u s Drury. 



