FRUIT-TREE BARK BEETLE. 



197 



Fruit-tree Bark Beetle. 



Scolytus rufjulosm, Ratzebiirg ; S, Immorrlions, Schmidt. 



H.K. 



Scolytus euguloscs.— Beetle, larva, and pupa ; all greatly magnified. The two 

 latter from drawings by Mr. E. Newstead. 



The above-named beetle much resembles the well-known 

 Elm-bark Beetle {Scolytus destructor, Oliv.), in its method of 

 doing harm by working in larval state within the inner part 

 of the bark and outer part of the wood, but is distinguishable 

 (for one thing) by being a good deal smaller, the Elm-bark 

 Beetle being from one and a half to as much as three lines in 

 length, and the "Fruit-tree" Scolytus only from three-quarters 

 of a line or less, to a line and a quarter long. 



The infestation has long been known on the continent of 

 Europe, and noted as feeding in the bark and sap-wood of 

 various trees, especially Apple, Plum, and Cherry. In the 

 United States "available data indicate that Plum is more 

 susceptible to attack than other trees ; while Peach, Cherry, 

 and Ai^ple are attacked about equally. Pear is also quite 

 subject to infestation; and Apricot, Nectarine, and Quince 

 trees are known to have harboured the species."* In this 

 country it has not been (so far as I am aware) noticed as more 

 than " rather common " until 1895 ; and until I received in 

 that year specimens of small boughs of Plum much injured 

 by its presence, I was not aware of it being one of our decided 

 orchard pests. 



On the 7th of June, Mr. Eobert Newstead, F.E.S., Curator 

 of the Grosvenor Museum, Chester, wrote to inform me that 

 he was sending me some pieces of Plum branches infested 

 with Scolytus rugulosus, of which he observed : — " By carefully 

 removing the bark you will find the insect in all stages, e. g. 

 larva, pupa, and imago. The branches are from Plum trees 

 in my father's garden at Ince, Cheshire, where the attack has 



• See Circular, No. 29, Second Series, United States Department of 

 Agriculture, Division of Entomology. By F, H. Chittenden, Assistant Ento- 

 mologist. Washington, March 25th, 1898. 



