350 PTEROPHORUS ACANTHODACTYLUS. 



Pterophorus ACANTHODACTYLUS. 



Plate CLXIII, fig. 5. 



At p. 149 of the twenty-second volume of the E.M.M. 

 is a description of the larva of Pterophorus cosmodac- 

 tylus ; a reference to it will show that in the year 1884 

 Mr. Eustace R. Bankes, of Corfe Castle, sent me about 

 a score of larvae of a Pterophorus, from which I bred a 

 series of P. cosmodactylus and two specimens of P. 

 acanthodactylus. Last year, 1885, Mr. Bankes sent me 

 another lot of larva?, from which I bred P. cosmodac- 

 tylus only. Notwithstanding this large proportion of 

 P. cosmodactylus, Mr. Bankes has all along been con- 

 vinced that in reality P. acanthodactylus is much the 

 commoner insect in his district ; and, therefore, again 

 this year, 1886, collected and sent me thirteen more 

 larvae from the Stachys sylvatica. They reached me 

 on the 25th of August, and, on opening the box, at 

 first sight they appeared to me just like those received 

 the two previous years ; they were of the same shape, 

 and there was precisely the same range of variation 

 from the bright green to purple forms. Two days 

 afterwards, however, on comparing them closely with 

 my descriptions of the previous years' larvae, it at once 

 became apparent that there were distinctly defined 

 distinctions between them ; so much so, that I at once 

 wrote to Mr. Bankes stating that I fully expected to 

 breed P. acanthodactylus from them. On the 7th of 

 September a further consignment of larvae reached me 

 from my friend Mr. W. H. B. Fletcher, of Worthing, 

 who sent them (evidently without any doubt on his 

 part) as P. acanthodactylus. They seemed in every 

 respect like Mr. Bankes's larvae, so that I was now all 

 but certain it would be proved that these two closely- 

 allied species can be separated in the larval stage. 

 The result was perfectly satisfactory, for from Mr. 

 Bankes's larvae I bred thirteen P. acanthodactylus, 

 from the 7th to the 14th of September ; and from Mr. 



