1914.] 213 



ON DORTTOMUS MACULATUS, Marsh. { = TMNIATUS, Fab.), AND 



B. COSTIROSTRIS, Gyll. (DEJEANI, Faust). 



OF BRITISH COLLECTIONS. 



BY E. A. NEWBEET. 



A great deal of confusion seems to prevail concerning these two 

 species. This is no doubt partly owing to Fowler (Col. Brit. Isl. 

 V, 277) having stated that he preferred " to follow Bedel in keeping 

 them together." Bedel does nothing of the kind. Faust, who mono- 

 graphed the genus in 1882 (Bull. Soc. Imp. Nat. Moscou, pp. 386, 

 424), re-named costirostris, Gyll., calling it dejeani, and Bedel makes 

 use of this name. It is probable that this change was the cause of 

 the species being overlooked by Fowler, since Bedel (Fn. Seine, VI, 

 119) separates the two as good species, thus : — 



Second joint of funiculus at least twice as long as broad ; length 4 — 5 mm.... 



dejeani, Faust. 



Second joint of funiculus scarcely longer than broad ; length 3—4 mm.... 



txniatus, Fab. 



Although it is rather an exaggeration to say that the second 

 joint of the funiculus is scarcely longer than broad, still the difference 

 between the two is well marked, the shape of this joint is also much 

 more linear in dejeani, somewhat pear-shaped in maculatus. 



D. silbermanni, Wenck., seems to have no marked characters to 

 separate it from maculatus, Marsh., which is a variable insect, both in 

 size and colour. Fowler separates it as a variety, chiefly by size, and 

 Stierlin by its shorter and stronger legs. Bedel and the last (1906) 

 European Catalogue treat it as a synonym of tseniatus, Fab. ( = 

 maculatus, Marsh.). 



Dorytomus dejeani appears to feed solely on the aspen (Populus 

 tremula). It has been recently taken in some numbers by Mr. J. 

 H. Keys, in his garden at Yelverton, Devon. 



13, Oppidans Road, N.W. : 



August 13th, 1914. 



(At Cothill, Berks, D. dejeani is usually abundant in early 

 summer on a few small trees of Populus canescens, Sin., in company with 

 D. tortrix (plentiful), tremulse (sparingly), Bhytidosomus, and other 

 poplar-frequenting beetles. D. maculatus occurs freely on adjacent 

 sallow bushes, but it is very rarely to be found on the poplars. — J. J.W.) 



