Cecidomyia urticae. 



This species, known as "the nettle gnat,"'- causes irregular- 

 shaped galls on almost every part of the plant. In some places 

 it is most plentiful, in others quite unknown. In some beds 

 of Urtica dioica leaves and flowers of almost every stalk bear 

 galls. They occur on the leaves in numbers of eight or less, 

 and of fifteen or less on the flower-clusters. When on the leaf 

 they are usually pubescent, more so on the part affecting the 

 under than that of the upper surface. Those on the flower- 

 clusters are usually glabrous. Distortion of the leaf is slight, 

 as may be seen in upper leaflet in A, the most being a small 

 curl as in B. The larval chambers, C, are large with thin walls. 

 The larva eats its way out, falls to the ground to pupate, and 

 decay of the cell-walls takes place until a hole is made in the 

 leaf; or if the gall be situated as in lower leaflets in A, the 

 leaf becomes detached and falls ofi". 



The illustrations are of specimens gathered at Hastings by 

 the author. 



