Galls caused by the larvae of Diastrophus rubi Htg. 



on 



the stems of Rubus fruticosus Linn. 

 PLATE Jfi. 

 Synonymy of Inskct. 



Andricus Hartigi Marshall. 



Diastrophus rubi Marshall, Tasch., Mayr, Cameron. 



Habitat of the Common Bramble.— Very plentiful in every 

 part of Britain on waste places and disused country roads, 

 and in woods, hedges, coppices, etc., asserting itself in every 

 way. 



The Gall is formed by the enlargement of the larval 



chambers within the medullary tissues of the bramble. 

 Position.— On any part of stem. 

 Manner of Growth.— Irregular, spindle-shaped swellings. 



Colour. — Dark green while growing; brownish when past 

 maturity. 



Average Dimensions of a Mature Specimen. 



Length, 60 mm. ; breadth, 12 mm. ; girth, 16 mm. 



May be sought during any month in the year. 



The Growth is complete by the end of November. 



The Typical Condition of the gall is plurilocular. Usual 

 number of cells, 80. 



The Larv.E pupate in the gall. The imagines emerge during 

 the spring. 



Parasites. — Torymus macrop terns, T. rubi Schen., Eupelvius 

 annulicornis, Decatoma quercicola Foer., Eurytoma abrotani 

 Gir. 



The gall is also figured by " The Royal Natural History,' 

 sect, xi., p. 20; Peter Cameron, "British Phytophagou; 

 Hymenoptera" (Ray Society), vol. iv., plate 9. 

 109 



