Galls caused by the larvae of Xestophanes potentillae 

 Cam. 



the rhizomes of Potentilla reptans Linn. 



PLATE 13. 



Synonymy of Insect. 



Cynips potentilla; De Vill. 

 Aulax splendens Htg. 



„ abbreviatus Thoms. 



„ poteHtillcB Schenck, Marshall, Mayr. 



Habitat of the Cinquefoil.— Along hedgerow banks, edges 

 of woods, borders of meadows, by the side of most country 

 lanes ; abundant in Britain, except parts of Scotland. 



The Gall is formed by the accumulation of sap around the 

 larva, which live in aggregations of about eight in each 

 swelling. 



Position. — On the rhizome. 



Manner of Growth. — Gregarious ; coalescent ; glabrous; 

 globular when single. 



Colour. — Orange-yellow, reddish brown, chocolate-brown. 



Average Dimensions of a Mature Specimen (globular 

 form of an aggregation). 



Girth, 24 mm. 

 May be sought during any month in the year. 

 The Growth is complete by the end of October. 

 The Typical Condition of the gall is plurilocular. Usual 



number of cells, 8. 

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



the spring. 



SI 



