DIPTERA. 



347 



Cecidomyia (Rhabdophaga) saliciperda, Duf. 

 (Willow-wood Midge). 



This species injures the stems, from two years old and upwards, of 

 several species of willow, and can therefore be readily distinguished 

 from C. salicis, which confines 

 its attacks to young twigs. 

 In figs. 320 and 321 we have 

 a representation of the damage 

 done to a species from Kew 

 Gardens. Fig. 320 represents 

 a cross section of the stem, 

 showing the depth of the 

 injuries; and fig. 321 repre- 



Fig. 320. Section of willow stem showing injurUs 

 caused by Cecidomyia saliciperda. 



sents the damage as revealed by a very thin shaving or " slab " 

 taken off. 



As I received the specimens after the insects had hatched, I give 

 the following account from Dr R. 

 Stewart MacDougall : x 



" This is a tiny fly, 2 to 3 mm. long (the 

 female is a little larger than the male), 

 with head and thorax black or black- 

 brown, and with black hairing. The 

 wings are milky white, with whitish hairs. 



"The eggs, rounded and orange- 

 yellow, measure - 40 mm. in length. 



" The larva is rounded at both ends, 

 or somewhat spindle-shaped. It has a 

 well-marked anchor process, and on 

 magnification little projections can be 

 seen on the edge of the body, and warts 

 on the top of the body. 



"The pupa is bright yellow, the 

 limit of the wings reaching to ring 4 and 

 the feet to ring 8. At the base of the 

 antennae two brown horns can be seen. 



" The females lay their eggs on Salix alba, S. fragilis, S. caprea, 

 S. purpurea, S. viminalis, and exceptionally on white poplar. 



1 Journal of the Association of Economic Biologists. 



Fig. 321. Portion of bark mid wood 

 cut off to show the injuries of Ceci- 

 domyia saliciperda. 



