88 NEW YORK STATE MUSEUM 



Maple and oak twig pruner (Elaphidion villosum Fabr.) . 

 Small, clean-cut twigs of oak, maple or other trees falling during 

 the summer or hanging in a wilting or dry condition, are the most 

 striking signs of this insect's work. Numerous reports were received 

 the past season concerning injuries by this insect, especially from 

 the vicinity of New York City. Incidental observations along the 

 Hudson valley showed that this borer was unusually abundant. 

 It confines its operations largely to the smaller twigs, rarely cutting 

 branches with a diameter more than three-fourths of an inch. Limbs 

 injured by this borer have the central portion traversed to a greater 

 or less extent by a somewhat irregular gallery inhabited (plate 3, 

 figure i) by a legless grub about three-fourths of an inch long. The 

 parent insect is a grayish brown beetle with a length of about five- 

 eighths of an inch. The habit of cutting off the limbs, leaving only 

 a small portion of the bark or outer sap wood, affords an excellent 

 means of identifying the depredator and distinguishes its operations 

 at once from the wilting of twigs resulting from the oviposition scars 

 of the periodical Cicada, Tibicen septemdecim, or the death 

 of small twigs as a result of fungous infection. 



Normally the grubs fall with the severed leaves and remain in 

 their retreats over winter, consequently the systematic collecting 

 and burning of the fallen branches is the most economical method 

 of checking this borer. Ordinarily it does not cause serious injury, 

 though the brown, dead tips produce a very unsightly appearance. 



Periodical cicada (Tibicen septemdecim Linn.) . In- 

 juries by this insect are limited almost entirely to the damage caused 

 by oviposition, especially in young trees, since the latter are much 

 more liable to be severely affected. An interesting case came under 

 observation last summer; the trees belonged to Mr Hubert Gage 

 of Rhinebeck, and the initial injury was caused in 191 1. Many 

 of those badly affected were much stunted, and the most seriously 

 damaged twigs had made little or no growth. 



In a few cases there was during the past three years, less than 

 ten inches of growth, and in one or two instances the comparatively 

 vigorous development of last year had withered and died during 

 late summer, probably as a result of a deficient supply of sap, owing 

 to the interference of circulation by the abnormal tissues below. 



The obvious conclusion is that in the case of badly injured young 

 trees it is highly desirable to eliminate as much of the injured wood 

 as possible, even though severe cutting must be done for two or three 

 years, because it was evident from the condition of some of these 

 trees that limbs showing numerous scars would amount to very 



