July, lS!)2.j 173 



It is extremely like ccBspititiella, and is doubtless mixed up with 

 it in most collections, but it is a paler looking and more decidedly 

 ochreous insect, and the dark apical dashes which are quite the ex- 

 ception in ccBspititiella are, I think, the rule in glaucicolella. It makes 

 its appearance considerably later than ccBspititiella, not being fully out 

 before about the middle of July, and it continues on the wing till the 

 middle of August. It flies in fields and lanes, and more rarely in 

 woods. 



The larva is of niucli the same shade of mahogany colour as ccpspititiella, or 

 for the matter of that, as aUicolella, any difference that may be thought to be 

 present, on comparison, being due to the relative distance of the specimens from full 

 growth, for immature specimens of all three are rather reddish-brown than yellowish- 

 brown. The head and plates are black or blackish. The posterior pair of subplates 

 are absent on 4th, but the anterior pair are present, though faint, whereas they are 

 quite absent in ccespititiella ; the spiracular plate on 4th is also much larger than in 

 ccBspititiella, being nearly as large as the one on 2nd, and no trace of any dark mark 

 exists on the back of 12t;h. 



The larvae make their appearance at intervals through the autumn, 

 and are of very diff'erent sizes when the cold weather sets in and stops 

 their feeding. Some are quite small, and of these many still stay on 

 the panicles, hiding themselves among the seeds ; others are apparently 

 full grown, and hibernate lower down and out of sight amongst the 

 stalks ; all, however, great and small, wake up again in the early spring 

 and complete their development upon what is left of last year's seeds. 

 Of all the rushes with which I am acquainted glaucus is the best at 

 holding its seeds to a late date, many of the capsules retaining the 

 greater part of their contents until the following May, or even June. 

 It is not surprising then that J. glaucus is essentially, so far as my 

 experience goes, the favourite food of this insect, although it may also 

 be found on conglomeratus, effusus, lamprocarpus, and at times, so Mr. 

 Fletcher informs me, on acutiflorus. 



The fuJl-sized case is not to be distinguished from that of ccespi- 

 tltiella, and has no doubt been mistaken for it over and over again, 

 and always certainly so, if the search has been deferred until very late 

 in the autumn, or until the following spring, for at these times ccespi- 

 titiella is either in hiding or laid up for pupation, leaving the rushes 

 in possession of its ally. There is, however, one important diff'erence 

 between them : ccBspititiella, as I have shown, does without a case 

 until somewhere about the period of its last moult ; glaucicolella, on 

 the other hand, takes to a case whilst in the antipenultimate skin, that 

 is, with two moults still to pass. Hence there is no such thing as a 

 really small aud perfect case of ccespititiella, whereas, in glaucicolella 



