Galls caused by the larvae of Tephritis bardanae 

 Schrk. 



on 



the flower-heads of Arctium lappa Linn. 



PLATE 134. 

 Synonymy of Insect. 



Trypeta bardance Schik., Walker. 

 Habitat of the Common Burdock.— Plentifully distributed 



over the whole of Britain, growing, especially well on road- 

 sides overshadowed with trees, also in woods and waste 



places. 

 The Gall is formed by the larva feeding within the seed 



capsule thus causing it to become abortive. 

 Position.— In the flower-head. 

 Manner of Growth. — Gregarious ; glabrous ; from three to 



twelve galls in each head. 

 COLOU R.— Chocolate-brown. 

 Average Dimensions of a Mature Specimen. 



Height, 7 mm. ; breadth, 2 mm. ; girth, 6 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, 15. 

 The Larv^ pupate in the gall. The imagines emerge 



during August. 



These galls are so completely hidden within the flower- 

 head that their presence cannot be detected ; nor will pressure 

 between the finger and thumb be any guide in seeking them. 

 The flower must be taken to pieces and each seed examined. 

 They are very easy to rear. The shoots of Arctium lappa will 

 live in water, and as soon as the flowers die off, the heads 

 should be put in a glass jar with fine tulle across the opening, 

 and the imagines will soon after appear. 



The illustration is of specimens gathered at Hastings by 

 the author. 



282 



