﻿Pec. 1895.] Webster. North American Species of Diabrotica. 159 



the former species was not known to be destructively abundant in that 

 portion of Illinois. I have ample proof that longicornis breeds in de- 

 structive abundance in bottom lands along the Wabash River in Indi- 

 ana, which lands are subject to overflow annually, sometimes as late as 

 May or even June, thus indicating that both of these species may breed 

 freely in very low lands. Unfortunately, the earlier stages and habits 

 of the larvje of soror are unknown, and we cannot say whether it breeds 

 in high or low lands, nor can I say whether or not it prefers the higher 

 elevations of cultivated areas. 



In the species z^/VAz/^r and trivittata we have the same phenomena as 

 to distribution, the latter species occurring throughout California and 

 possibly southward, while the former ranges over the whole eastern por- 

 tion of the United States and into Canada, to the north, while it ex- 

 tends southward into Mexico, where we shall probably find that both 

 species cover the same area, though probably at different elevations. 

 In New Mexico, Prof. Cockerell has found a form intermediate between 

 these species and occurring between the regions occupied by them, 

 which he has called incerta, and which extends also southward into 

 Mexico. £>. triclncta, which occurs from Central America northward 

 to Colorado, might almost be said to occupy the same relation towards 

 D. i2-piinctata and soror, though Prof. Wickham found both at Albu- 

 querque, New Mexico, and Prof. Snow took both at Socorro, N, M., 

 the elevation of both localities being 5,000 feet. Prof. Cockerell 

 writes me that he finds D. 12-piinctata rarely at Santa Fe, elevation 

 7,000 feet, while it is abundant in the Mesilla Valley, elevation 3,800 

 feet; tricincta being rare. It certainly looks as though there was some- 

 where in Mexico or Central America a veritable nursery for species, and 

 where the evolutionist might revel in a scientific paradise. I cannot 

 help feeling that within the borders of Central America and Mexico we 

 may sooner or later discover the key that shall solve the mystery of the 

 origin of many of our species of Diabrotica. 



To me longicornis is above all others the most interesting of the 

 Diabrotica, not because of its economic importance, but on account of 

 its extended range and peculiar distribution. Occurring, as it does, 

 from Yucatan northward through Mexico, New Mexico to Colorado, 

 Kansas, Nebraska and Iowa, it sweeps to the northeast through Illinois, 

 Indiana and western Ohio, while it is known to occur abundantly about 

 Buffalo, N. Y., where it has been collected by Mr. Reinecke, and also 

 at Aulac, New Brunswick, by Mr. W. Hague Harrington. With the 

 possible exception of the Boreal, it thus inhabits every Life Zone on 



