DIASTROPHUS EUBI. 73 



usually reddish ; generally the abdomen is black, but 

 it may be piceous; and the ventral surface is often 

 reddish ; the thorax also may have fulvous or reddish 

 blotches ; the areolet may be obsolete or semi-obsolete. 



The nearest allied species is D. Mayri, Reinhard, 

 which agrees with it very closely, but may be best 

 known by the antennae being 14-jointed in both sexes 

 (sometimes, however, 15-jointed in $ according to 

 Reinhard) ; the thorax and abdomen are more slen- 

 derly built, the basal abscissa of the radius is thicker 

 and geniculately curved, and the areolet is never 

 denned. D. Mayri forms galls on Potentilla argentea. 



Gall. — Forms irregular, spindle-shaped swellings on 

 the stems of Bubus fruticosus, B. c&sius, and B. 

 idxus ; smooth, or beset with small elevations caused 

 by the larval chambers ; or more or less of it may be 

 thickly covered with small spines, and may even bear 

 large spines. They are green when young ; get 

 brownish when old. In length they range from two 

 to eight inches. They contain numerous oval larval 

 cells, embedded in the medullary sheath; the cells 

 have a distinct wall of a yellower colour than the pith, 

 and have an average diameter of about 2^ mm. ; and 

 are, as a rule, situated quite close to the outer rim or 

 back. 



Parasites. — Torymus cynipoides, Gir. (this is pro- 

 bably a MS. name), T. macropterus, T. rubi, Schenck, 

 Eupelmus annulicomis, Encyrtus ruborum,* Gir., Deca- 

 toma quercicola, Foer., Eurytoma quercicola, Foer., 

 E. diastrophi, Gir., E. abrotani, Pteromalus incras- 

 satus, Rtz. (Brischke). 



Local, but with a wide range. 



Sweden, Germany, Austria, France. 



* This is on the authority of Giraud (Ann. Soc. Ent. Fc, 1877, 

 p. 423), but there is probably a mistake here. 



