20 



EVOLUTION IN COLOR-PATTERN OF THE LADY-BEETLES. 



The resemblance of this species to H. convergens, and especially the simi- 

 larity of their larvae, is such that it has probably been derived from that 

 older type at no very distant date. The pronotal pattern is like that of H. 

 convergens, but shows relatively less variation (fig. 9) . 



Var. A. The humeral spot 

 absent. In 9 out of 26, or 

 35 per cent of the males, 

 and in 6 out of 29, or 21 

 per cent of the females at 

 Cold Spring Harbor. 



Var. B. Spots 4 + 5 + 6. 



SeveraJ taken from di- 

 verse localities. Nowhere 



established (fig. 8, i). 

 Var. C. Spots 6+4 + 5. 



As above (fig. 8, h). 

 Var. D. Spots 4, 5, fcnd 6 



merged in one rounded 



area (fig. 8, j). Only 1 



specimen seen. 



Var. E. With spot No. 2; 



3 cases in 55, or 6 per cent, 



at Cold Spring Harbor 



(fig. 8, a). 

 Var. F. With the extensa 



mark. Only 1 specimen 



at Cold Spring Harbor 



ttfe.*,*). 

 Var. G. Spots 4, 5, 6 (fig. 



FIG. 8. Variation of elytral pattern of Hippodamia glacialis. 

 Var. H. Without discal 6 = mode. 



spots on pronotum. Only 



1 specimen from Cold Spring Harbor. Also seen in the H. convergens var. pseudogla- 



cialis of the Western States. 

 Var. 7. Median white spot upon head extending to eyes. Especially characteristic of 



western specimens (fig. 10). 



o w^mj m^r mmm i^p 10 ^ ^J 



\a b c d i b c d 



FIG. 9. Variation of pronotal pattern of Hippodamia glaciali*. b = mode. 



FIG. 10. Variation of color-pattern of head of Hippodamia ylacialis. rf = modc; a- from Onaga, Kansas; 

 c to e from Cold Spring Harbor, New York. 



The appearance of spots 2 and 3 and of the scutellar mark, which is 

 occasional, may be looked upon as reversionary. The extensa mark is also 

 met with in H. convergens var. extensa and is a case of parallel variation. 



