Galls caused by the larvae of Lipara lucens Mg. 

 the stem of Arundo Phragmites Ben. 



PLATE 32. 



Synonymy of Insect. 



Habitat of the Common Reed.— Common in Britain in 

 marshes, streams, shallow pools, ditches by railway em- 

 bankments, and lakes in private parks. 



The Gall is formed by the leaves overlapping and enfolding 

 one another, this being caused by the larva preventing the 

 upward growth of the stem. 



Position.— At the top of the stem. 



Manner of Growth.— Singly ; glabrous, glossy ; torpedo- 

 shaped. 



Colour. — Yellowish green. 



Average Dimensions of a Mature Specimen. 

 Length, 70 mm.; breadth, 10 mm.; girth, 26 mm. 



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

 and September. 



The Growth is complete by the end of August. 



The Typical Condition of the gall is unilarval. 



The Larva pupates in the gall. 



These galls are not common. This fact is due mainly to 

 the cutting down of the reeds in many parts of the country 

 during September for thatching purposes. They are often 

 very difficult to obtain, unless the gallist can go amongst the 

 reeds in a boat, or search the stems after they have been 

 thrown on the bank by the mower. In the illustration will 

 be seen, on the right side of the centre galled stem, a panicle, 

 and on the left side an unaffected stem. The galled stems never 

 produce panicles. 



The illustration is of specimens gathered in Ashburnham 

 Park, Battle, by the author. 



