Urophora cardui. 



This conspicuous and unmistakable gall may often be 

 seen on the thistles growing on a patch of waste ground. The 

 galls occur at the summit of the plant and also at the 

 nodes, and in almost every instance prevent a continuation of 

 growth. In the early stages of development it is very soft 

 and sappy, the outer layer more so than the interior. It, 

 however, soon becomes more solid, and continues to harden 

 until it is of a woody nature. At first it is a delicate pale 

 green ; this with age changes to a dark green, and ultimately, 

 in unison with the rest of the plant, turns brown. Leaves 

 spring in all directions from the surface of the gall, and at 

 the top form a tuft, imparting a graceful and attractive 

 appearance. Such a specimen may be seen in the lower 

 corner on the right-hand side of plate 33. The larvae are 

 usually four in number, each occupying a separate gallery. 

 They eat from above downwards, increasing the size of the 

 gallery as they descend. 



The illustration is of specimens gathered at Hastings by 

 the author. • 



