Galls caused by the larvae ot Ceoidomyia taxi Inch. 



on 



the terminal leaves of Taxas bnccata Linn. 



PLATE 88. 



Synonymy of Insect. 



Cecidomyia taxi Theobald. 

 Habitat of the Common Yew.— This tree may be found in 



the graveyards of many rural churches throughout Britain, 



also in private grounds and parks, where it is frequently 



cultivated for hedges. 

 The Gall is formed by the leaves being united together, 



forming a cone-shaped tuft, which ultimately expands 



somewhat and forms a small rosette. 

 Position. — At the termination of a twig. 

 Manner of Growth. — Singly and gregarious ; as many as 



seventy leaves in one cluster. 

 Colour. — The exterior leaves are normal, the inner ones are 



white and yellow. 

 Average Dimensions of a Mature Specimen. 



Height, 1 6 mm.; girth, 36 mm. 

 May be sought during any month in the year. 

 The Growth is complete by the end of May. 

 The Typical Condition of the gall is unilarval. 

 The Larva pupates in the gall. The imago emerges during 



June. 



These galls are due to the deposition of an ovum by C. taxi 

 at the extreme tip of the shoot, the action of the larva pre- 

 venting further growth of that part. The larva lives in the 

 centre of the leaves during the autumn, winter, and spring, 

 and when about to pupate works its way towards the apex 

 of the cone ; the emergence of the imago is thereby rendered 

 more easy. 



The gall is also figured by F. V. Theobald, "Journ. S. E. 

 Agri. Coll.," March, 1899. 



The illustration is of specimens taken at Crowhurst, Sussex, 

 by the author. 



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