439] COLORS OF TIGER BEETLES— SHELF ORD 45 



Atlantic coast and for some distance inland in Massachusetts to Mary- 

 land where the markings are of the type shown in figure 532 and slight- 

 ly wider with the all joined at the side. The sharp forward bend of 

 the middle band is characteristic of the eastern forms. C. formosa is 

 distributed about the sand dunes of Lakes Michigan and Erie and 

 through the sand areas of the central states, the distribution being very 

 nearly like that of C. scutellaris except that formosa is wanting from 

 Virginia to Texas along the Atlantic and Gulf Coasts. 



The markings of the western Mississippi basin forms are broad as 

 shown in figure 531, plate XXVIII, while in the more southern and 

 western forms from Texas, Colorado, and Oklahoma are characterized 

 by a middle band tending to be straight across the elytron. 



The species which stands close to this is C. venusta (Figs. 533 and 

 534). The pattern is similar to that of C. generosa. It occurs only in 

 sand areas of the great plains. The southern representatives have 

 markings similar to figure 531 in width, but in Manitoba there is a 

 tendency to the extension of the white as shown in figure 534. C. lim- 

 bata is a closely related species which is taken only in blowouts in sand 

 hills of the western Nebraska region and of Manitoba. Figures 535 and 

 536 show typical patterns. They do not vary greatly geographically. 



C. ancosisconensis and duodecemguttata are invariable species (Figs. 

 528 and 529), repanda a subspecies of 12 guttata distributed almost 

 everywhere east of the Rocky mountains in the United States and Can- 

 ada. Specimens from Louisana, Manitoba, and Virginia do not vary 

 appreciably. The larvae inhabit very moist soil and soil temperature 

 cannot be of any magnitude. The habitat and larval habits are such 

 that variations due to differences in temperature and moisture are not 

 common. If the soil becomes too dry the larvae leave it and dig a new 

 burrow in soil of the wetness required by the species. Since they 

 occur near water courses, this tends to keep larvae in similar conditions 

 no matter in what latitude they occur. The variation of oregona, a 

 related species, has not been studied. 



C. hirticollis occurs on the sandy shores of the sea, lakes, and 

 rivers from Vera Cruz to California, the Great Lakes, and Massachu- 

 setts. The pattern which is shown in figure 330, plate XVI, is quite 

 invariable as compared with the rest of the species considered. High 

 temperature experiments performed with these showed clearly recogniz- 

 able modification in which the pattern duplicated Southern and South- 

 western forms. The experiments and geographic and other variation 

 are likewise parallel. 



C. sexguttata has been studied and shows peculiar variations. Spec- 

 imens from the Northeastern United States and the region of the Great 

 Lakes have well developed markings (Figs. 525 and 526, PI. XXVIII). 



