THE ECTOPARASITES OF THE RED GROUSE 371 



finally determine the species of the moth, but I think it is Coleophora ccespititiella, * 

 for this species frequents many species of rush ; whereas the C. glaucicolella, the 

 other inland species, is most partial to Juncus glaucus. The former is usually 

 fully out by the middle of June and lingers on- till the middle of July ; the 

 last-named moth issues about the middle of July and flies for four weeks. 

 The case is whitish, semi-transparent, and with brown specks ; it is found 

 when the larva is no longer young, but not at any very fixed time. At first 

 its outer end is closed. The larva often leaves the case, burrowing into the rush- 

 head for food, and at times fails to refind it. Before pupating, the outer or anal 

 end of the case is opened and the case strengthened by a glandular excretion. 

 These larvae should be searched for cysts. 



1 J. H. Wood, Entmiiologists 1 Monthly Magazine II.,Ser. iii. (xxviii.), 1892. 



