THE ENTOMOLOGIST 



Vol. XLL] JULY, 1908. [No. 542 



LIFE-HISTORY OF LYCMNA ACIS. 

 By F. W. Frohawk, M.B.O.U., F.E.S. 



On July 1st, 1907, I received from Prof. Rebel, at Vienna, 

 four living females of Lyca-na acis, who kindly sent them to me 

 at the request of the Hon. N. Charles Rothschild. I am, there- 

 fore, indebted to both these gentlemen for their kind assistance 

 in procuring me living examples of this extremely rare British 

 species. 



I at once placed all four females on growing plants of 

 Anthyllis vulneraria. On July 5th I noticed a few eggs were 

 deposited, and several more on the following day ; in all from 

 thirty to thirty-six ova were laid on the calyces of the flowers, 

 mostly near the base, and often hidden between them. 



The egg is very similar to that of L. arion, being of the same 

 size — e. g. ^^j in. wide — but slightly higher (-^q in.) and of 

 similar structure ; the micropyle, however, is much smaller, 

 and but slightly sunken, resembling in this respect the egg of 

 L. argiades. The whole surface is covered with a beautiful 

 reticulated network pattern ; the reticulations surrounding the 

 micropyle are simple, but gradually develop at each juncture 

 into raised knobs, which are prominent elsewhere over the 

 surface. All the reticulations resemble white-frosted glass, 

 reflecting the beautiful pale blue-green ground colour of the egg. 

 Shortly before hatching it assumes a greyish tinge. The egg- 

 state lasts ten days. The eggs laid on the 5th hatched on the 

 15th. The young larva makes its exit by eating a small hole in 

 the side of the egg just large enough to allow of its escape. 



Directly after emergence the larva is very small, being 

 only 3^(3 in. long, but stout in proportion. It is almost exactly 

 similar in all respects to L. arion, except that the hairs of acis 

 are longer and the general colouring of the body is of a greener 

 tinge. It has a shallow dorsal longitudinal furrow ; on the 

 first segment, which is the widest, there is a large dorsal disc 

 and a smaller one on the anal segment ; both are some- 



ENTOM. — JULY, 1908. O 



