THE ENTOMOLOGIST 



Vol. XXXVIII.] JANUARY, 1905. [No. 500. 



THE EARLIER STAGES OF CATACLYSTA 

 LEMNATA, L. 



By T. A. Chapman, M.D. 



(Plate I.) 



On June 4th, 1904, being at Bookham with the South London 

 Entomological Society, I observed C. lemnata in some abund- 

 ance, and remembering that it was the only one of the Hydro- 

 campas (except Acentropus) with whose early stages I had no 

 acquaintance, I took home a supply of moths, with a view to 

 obtaining eggs. 



Curiously enough, I found, on looking into the matter, that 

 all the other species had been well reported on by various 

 authors, but I could find nothing better about lemnata than that 

 by Buckler, who tells us nothing of its history earlier than Nov. 

 10th, when it is beginning to think of hybernation. 



The way in which lemnata lays her eggs interested me perhaps 

 as much as anything in its history. It lays them under water, 

 and that surface of the egg which in the case of nearly all Lepi- 

 doptera is exposed to the air, is in that of C. lemnata bathed in 

 water. This fact has never been recorded of C. lemnata, but it 

 has been, I think, of all the other Hydrocampas ; A. niveus 

 (female) appears to go under water to do so, but the others 

 apparently only submerge their ovipositors. The curious fact 

 that all these eggs are truly aquatic is one that I had never 

 clearly understood, probably because attention has not been 

 called to it in records; for example, Buckler (E.M.M. xiv. p. 97) 

 records how Mr. W. E. Jeffrey got H. stagnata, Don., to lay eggs, 

 which he found placed in little batches on the under side of 

 floating pieces of Sparganium. Not being pointedly told that 

 the eggs are in the water and wetted by it, one reads the fact 

 along with the accounts, which are much more abundant, of how 



ENTOM. — JANUARY, 1905. B 



