128 



The GalLs of Essex; a Contribution to a 



Artemisia vulgaris, L. Leaf. Small, red or red and 

 green galls on the upper surface of the lower leaves. The 

 larvae pupate withm the galls. Cecidomyia foliorum, H. 

 Loew. 



Carduus arvensis, Curt. Stem. 

 The stem is considerably swollen 

 into a hard, woody, ovate, or 

 globular gall, but the stem con- 

 tinues to grow and leaves are pro 

 duced above the gall. The gall is 

 most commonly found in cultivated 

 fields. The galls are multilocular, 

 containing from two to eight fat, 

 white larvae with brown heads, 

 which pupate within the gall. Uro- 

 PHORA Cardui, Linne. (Fig. 12 1. 



Centaurea nigra, L. Flower- 

 head. The ovary is transformed 

 into hard, woody, irregularly oval, 



confluent galls to the number of two or three in one flower- 

 head. The appearance of the head is not changed, and the 

 galls are only tactilely noticeable. The white larvae change 

 to black pupae within the gall. Urophora solstitialis, Linne. 



HiERAciuM umbellatum, L. Stem. Hairy, green, rounded 

 swellings of the stem, generally of about the size of a walnut. 

 The galls are multilocular, and the larvse pupate therein. 

 AuLAx HiERAcii, Bouche (== A. Sabaudi, Hartig). 



Campanulace^. 



Campanula rotundifolia, L. Seed capsules. The galled 

 capsules are much swollen, and become much thickened and 

 fleshy ; they are not, however, particularly noticeable. The 

 black larvae pupate within the galls, often two in one capsule. 

 Gymnetron Campanul^e, Linne. 



Fig. 12. Urophora Cardui. 



JasminacevE. 



Fraxinus excelsior, L. Leaflets. The midrib of the 

 leaflets is much swollen, enclosing an oval purse-like chamber 



