54 



EVOLUTION IN COLOR-PATTERN OF THE LADY-BEETLES. 



3051 a. Hippodamia apicalis Casey. 



Distribution: Colorado to California, Arizona to Washington. 



This species is closely allied to the the previous one (see fig. 43). It is 

 given specific rank because of its smaller size, darker pronotum, different 

 head and elytral pattern, and lack of intergrades. Since its range is within 

 that of H. parenthesis, which it does not displace, it can not be a subspecies 

 of it. In the following descriptions, a is a black mark along the suture at 

 and near the apex. 



Typical pattern: Spots J+3, 1+2, 4+5+6+ a. (Fig. 43, e.) 



Var. Spots J+3, 1+2, 6+4+5+6+ o inclosing alight spot. Arizona. (Fig. 43, h.) 

 Var. Spots J+3, 1+2+4+5+6+ a off. arctica Schneider. Nevada and Utah. (Fig. 



43, flr.) 



Var. Spots J+3, 1, 5, 4+6+a. Idaho. (Fig. 43, i.) 

 Var. Spots J+3, 1, 4, 5, 6+a. Colorado and Wyoming. (Fig. 43, c.) 

 Var. Spots J+3, 1, 4, 6+a. Colorado and Wyoming. 

 Var. Spots J+3, 5, 4+6, . Colorado and Wyoming. 

 Var. Spots J+3, 1, 4, 6, a. Colorado and Wyoming. 

 Var. Spots J+3, 1, 4, a. Colorado and Wyoming. 

 Var. Spots J+3, 1, a. Colorado and Wyoming. 



The pronotum is always much darker than in H. parenthesis, the caudal white spot 

 being especially reduced. The head has 2 spots near the cephalic border in- 

 stead-of 2 pyramids with their bases upon the border, as in H. parenthesis* 



FIQ, 43. Variation of elytral pattern in H. <n>icalix. e =- mode; a, from California; 

 b, il, from Colorado; c from Wyoming; r,f, (/, from Nevada: h. from Arizona; 

 /, from Idaho. 



Subspecies of Nevada and Utah: Spots never found missing and the vit- 

 tate variety frequent. 



Subspecies of Colorado and Wyoming: The spots much reduced and some 

 frequently lacking. 



Subspecies of Arizona: The black pattern much enlarged but not vittate. 

 A further development in this direction is seen in Southern California in 



H. lengi. 



Hippodamia apicalis is more closely allied to the European H. arctica and 

 the Siberian H. amoena than to H. parenthesis, and is, I believe, the Amer- 

 ican representative of H. arctica. 



