346 



FOREST ENTOMOLOGY. 



Thorax light yellowish - orange beneath, above pilose dark. Wings 

 as in male ; abdomen orange, with paler oviduct, and covered with 



black hairs ; legs uniformly dark- 

 brown, with greyish pubescence. 



Cecidomyia (Rhabdophaga) rosaria, 

 Lw. (Willow Rose-gall Midge). 



The galls caused by this insect 

 (fig. 318) are fairly common in 

 Northumberland, more especially in 

 the hilly districts, where there is 

 an abundance of scrub of the goat 

 willow (Salix cajprea). The galls 

 may be found throughout the winter 

 months after every leaf has disap- 

 peared, and as many of the larva? 

 pupate within the gall, it is well to 

 collect them when dry for artificial 

 The insects appear about the middle of May, and deposit 



Fig. 318. Shoots o/Salix caprea injured 

 by Cecidomyia rosaria. 



breeding. 



x 



their eggs in the terminal shoots. The gall very soon forms, as I have 

 found it by the first week in June. The gall itself is simply a rough 



rosette of leaves formed in conse- 

 quence of growth being arrested. 

 Adult insect, female. Expanse 

 of wings about 6-8 mm. Anten- 

 nae lightish, inclining to grey on 

 upper side. Thorax greyish, 

 very hairy. Abdomen flesh-col- 

 oured, telescopic portion of seg- 

 ments very elastic, other por- 

 tions dark and hairy, under side 

 uniformly flesh - coloured, with 

 greyish silken hairs. Eyes black, 

 wings greyish, veins dark-grey. 

 Halteres light. Legs greyish, with red foot. 



Male. Antenna? greyish-black, and joints very hairy. Eyes black. 

 Base of wing flesh-coloured. Thorax darkish grey, hairy. Abdomen 

 uniformly grey, and hairy. Legs same as in ? . (Fig. 319.) 



/ 



Fig. 319. Cecidomyia rosaria {male). 



