5 



DISTRIBUTION AND DISPERSION OF LEPTINOTARSA. 



DISTRIBUTION OF THE OTHER GROUPS. 



The distribution of the other groups presents on examination much the 

 same history as that found in the lineata group, with the exception that none 

 of them are as widely distributed or as variable, or present the interesting 

 series of migrations and the interrelation of species, as does the lineata group; 

 hence the history of this group has been presented in full, while the others 

 may be passed over with only a few comments. 



In the lineata group it was shown that the various species are restricted 

 in a striking manner to natural environmental complexes. In the other 

 groups also this same limitation is seen, and the extent to which the develop- 

 ment of the different groups has given rise to species in the natural divisions 

 of the country can best be shown by the following table : 



Table 2. Distribution oj Leptinotarsa by Groups in the Different Faunal Areas. 



