EFFECTS OF WARMTH, ETC, ON SILKWORM LARV.K. 127 



except that of a pair of Larentia salicata, one of which I caught 

 whilst taking a flying jump over a hedge. 



We were up again the next morning at 6 o'clock, setting our 

 captures of the day before ; this did not detain my friend very 

 long, but kept me without a stop, with the exception of breakfast, 

 hard at work until 12.80, when Mr. Threlfall returned disgusted, 

 having only found six larvae of Spilonota lariciana, where he 

 expected to obtain a quantity. As we dined at 2 o'clock we 

 thought we could not fill up the time better, until that desirable 

 meal was ready, than by collecting the larvae of Dici'orampha 

 consortana, which we accordingly did. For the benefit of those 

 who are unacquainted with the habits of this larva, it draws 

 together the flower-head and leaves of the ox-eye daisy, twisting 

 it up with a most unmistakable care, and feeds concealed therein. 



In the afternoon, a strong north-east wind having arisen, we 

 were driven to the only sheltered spot about, viz., at the back of 

 a short range of rocks, where, amongst the heather and golden- 

 rod, we completed a series each of Catoptria aspidlscana and 

 Phoxopteryx unguicana; besides which, among sorrel {Rumex 

 acetosella), Gelechia velocella occurred sparingly. 



We tried again in the evening for Larentia salicata, but the 

 wretchedly cold wind drove us into our inn, where we consoled 

 ourselves with talk of what we might have caught if the weather 

 had been more propitious. 



8, Winckley Square, Preston, May 17, 1882. 



EFFECTS OF WARMTH AND SURROUNDING ATMO- 

 SPHERIC CONDITIONS ON SILKWORM LARV^. 



By E. a. Ormkrod, F.M.S. 



The very useful note of your correspondent, Mr. Dobson, 

 regarding efi'ect of heat on Notodonta dictcea (Entom. xv. p. 65), 

 suggests that a few observations I made in West Gloucestershire 

 about ten years ago, on effects of temperature and of atmosi3heric 

 conditions on rate of development of common silkworm larvae, 

 may be of some little interest ; though, at the same time, I rather 

 hesitate to ofl'er them, as, with regard to such a well-observed 

 larva, it may be that every point has already been noted. 



