25-i [NoTember, 



On first seeing this beetle I thought it must be /. acuminatus Cryll., 

 but at the same time was surprised to find acuminatus so smalh I then 

 tried to identify it with nigritiis {sutiiralis') GylL, which has been 

 recorded once or twice in Britain. On showing the specimens to 

 Dr. Munro he at first took them to be nicjriius, and we endeavoured to 

 place the beetle as such with the help o£ Reitter's key, only to find that 

 it would not do. This key seemed to place it as erosus, and on subse- 

 quent comparison with sj^ecimens of both nigritus and erosus in the 

 British Museum I satisfied myself that it was the latter. Col. Sampson 

 has since very kindly confirmed this identification. As far as my memory 

 goes, Eichhoff gives as the distribution of Ips erosus, S. Europe, the 

 Mediterranean Coast, N. Africa, and the Landes in France, and its prin- 

 cipal host-tree as Pinus maritima. The fact that it is a Mediterranean 

 species makes it doubly interesting that it should have arrived in this 

 country and succeeded in establishing itself as successfully as I found it 

 to have done. In this connection Dr. Munro tells me of a record during 

 the summer of 1920 (?), the only record, to his knowledge, of erosus 

 being taken on P. maritima-iixaheY, on a ship from the Mediterranean 

 Ij^ng in Cardiff Harbour. It would seem, therefore, that some of these 

 individuals must have been put ashore, and have since found their way 

 up the Bristol Channel to the Forest of Dean, where they have taken 

 quite successfully to P. sylvestris in place of the usual P. maritima. 

 It is, of course, possible that these two records in two succeeding years 

 are merely coincidences, bearing no particular relation to one another, 

 and that erosus has been established for some years in the " Dean." It 

 seems improbable however that, had such been the case, the beetle should 

 have escaped notice until the present. The Scolytidae are a compara- 

 tively small family in this country and have been well worked over, and 

 the " Dean " is a favourite hunting-ground. Moreover, the beetle, if 

 taken in its brood-galleries, could not be mistaken, its ajjpearance dis- 

 tinguishing it at once from any species other than laricis, and the 

 pattern of its brood-gallery from the latter. I. erosus is a polygamous 

 species, and constructs very clearly defined, many-armed (usually 3 or 4) 

 galleries, diverging in a longitudinal direction from a small and narrow 

 central " Kammelkammer." The larval-galleries are given off on either 

 side more or less at right angles, and for some distance are ver}^ clearly 

 defined and regular, after which they intermingle and become confused. 

 The general effect is a very clean regular pattern. The galleries, both 

 adult and larval, are chiefly in the bast, but slightly score the sapwood. 



The fact that tliis beetle was found in such large numbers, and 

 apparentl}^ so firmly established, would lead one to su])pose that it is a 



