Galls caused by the larvae of Rhodites spinosissimse 

 Giraud 



on 



the stems and leaves of Rosa spinosissima Linn. 



PLATE J^2. 

 Synonymy of Insect. 



Rhodites spinosissivice, Schen., Tasch., Mayr, Cameron. 

 Habitat of the Burnet, or Scotch, Rose.— This rose 



is common in Scotland, but not in England and Ireland. 



It is generally found on dry and bushy wastes, and is 



essentially a maritime plant. 



The Gall is formed by an accumulation of sap around 

 the ova producing large swellings in the medullary tissue. 



Position.— On the stem, leaves, leaf-stalks, and sometimes 

 flower-buds and petals. 



Manner of Growth.— Conglomerated ; glabrous ; glossy. 

 Colour.— Green ; when mature, dull or bright red. 

 Average Dimensions of a Mature Specimen.— On a stem. 



Length, 32 mm. ; on a leaf, girth, 36 mm. 

 May be sought during the months of June, July, and August. 

 The Growth is complete by the end of July. 



The Typical Condition of the gall is plurilocular. Usual 

 number of cells, 8. 



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

 the autumn. 



I NQUILINE.— /-^r/^/w/wj ca)ii7i(z. 



Parasites.— r^^/jw^j viacropterus, T. difficilis Nees., Mega- 



stigvius tmnsversus Walker, Pterotnalus inflexus Fo^r., 



P. incrassatus Ratz. 



The gall is also figured by Cameron, " British Phytopha<-ous 

 Hymenoptera," vol. iv., plate 11. •'ft, 



"3 8 



