174 



THE ENTOMOLOGIST. 



experience of the larvae had shown him no structural difference, 

 while the coloration of succenturiata larvae changed entirely when 

 the food-plant was changed from A7'te7nisia or Tanacetimi to 

 flowers of Achillea. He added that Dr. Draudt's careful work at 

 the eggs {vide ' Iris,' xviii. 308) had also failed to educe any 

 differential characters, although that author found more indi- 

 vidual variation in both than in any other species of the genus. 

 I may remark here that Mr. J. Gardner, of Hartlepool, admits 

 that " in beaten larvae I certainly would not undertake to say 

 whether they were those of E. succenturiata or E. subfulvata," 

 although his experience satisfies him that they are two species 

 (Ent. Eec. xix. 24). Herr Dietze recognizes (in the letter just 



Succenturiata, 



SUBFULVATA. 



referred to) a pupal difference, but remarks that a similar varia- 

 tion in the colour of the wing-cases occurs in E. ahsinthiata. As 

 regards the genitalia, however, my old friend and colleague, 

 Mr. F. N. Pierce, is entitled to have his say, as he is such an 

 authority on this particular study. Although he freely admits 

 that the differences are very slight, he is able to venture a fairly 

 definite statement {in litt., 29th January, 1907), as follows: — 

 " I examined suhfulvata a,nd succenturiata many 3'ears ago, and 

 only last night, now that I know the parts better, am I able to 

 say definitely there is a difference. I enclose a rough sketch of 

 the largest of the three teeth processes,* and am also sending for 



■■' This sketch is reproduced in the accompanying cuts, by Mr. Pierce's 

 permission. 



