Origin and Diffusion of Rlissi4s leucopterus and Murgantia histrionica. 143 



Florida to Atlantic City, New Jersey," and adds that " the unique ap- 

 pearance of the fullgrown chinch bug, with its white wings and chalky 

 white pubescence, forcibly indicates that the insect is either a 

 psammophilous or maritime species"; and he further expresses the opin- 

 ion that its geographical distribution fully bears out the theory that it 

 belongs to the latter class It will be observed that this habit of clust- 

 ering about the tufts of grass, along the sea shore is borne out by Mr. 

 Harrington's observations, much farther northward. It appears to me 

 that Mr. Schwarz, in his statement that the species is probably a 

 maritime one, has given us the key to the whole problem, and I shall 

 discuss this factor, at length, farther on, and will only here suggest 

 that it is sub-maritime instead of maritime, and also add to the mass 

 of proof there presented, going to show that the species is capable of 

 sustaining itself on grasses, by calling attention to the fact that during 

 the recent outbreak in Ohio, almost without exception, all of the com- 

 plaints of ravages in the north-eastern part of the State were of in- 

 juries to grass. It seems to me that we now have before us ample 

 proof that this insect may not only exist, but become abundant, per- 

 fectly independent of cultivated grains. 



The question of a westward advance of the species from the 

 Atlantic coast, is however, a valid one and must be carefully consid- 

 ered. Fitch states, in his second report, p. 278, that the insect first 

 began to prove destructive in North Carolina in 1783. Webster, in 

 his work on Pestilence, Vol. I, p. 279, states that, in 1785, fields of 

 wheat in North Carolina were so overrun with these insects as to 

 threaten total destruction to the grain. Now, if I mistake not, North 

 Carolina had, at this time, become about as thickly populated, and 

 agriculture had advanced to about the same magnitude, that it had in 

 the west when the species first began to attract attention in 1823 in 

 Southern Illinois, 1850 in Northern Illinois, 1855 in some portions of 

 Iowa, and in Kansas, Nebraska and Minnesota later on. That is, 

 these insects began to attack cultivated plants over the whole area of 

 their present habitat, where they have been destructive, at about the 

 same period of agricultural development, and density of rural popula- 

 tion. The trend of these has been westward, but the fact does not 

 prove the non-occurrence of Blissus leucopterus in considerable num- 

 bers, prior to the advance of this wave of civilization and agricultural 

 progress. The only data upon which the assumption that the two 

 phenomena were co-existent, is, so far as I am aware, based on the fact 



