184 



black beetle about half an inch long and less than a quarter of an inch 

 broad, with a flattened rough back. Little is known of its habits 

 excejot that it occurs in ants' nests. It is not (common. 



Aphonus tridenialus Say resembles the smaller muck-beetle, Ligyrus 

 gibhosus, treated on page 98 of this rei:)ort, exce])t that it has no trace 

 of any indentation on the front part of the thorax. Its habits appear 

 to be very similar to those of the muck-beetles. Two correspondents 

 of Professor F. L. Harvey,* in Maine, sent him specimens of the adults 

 taken in late June and early July from injured hills of corn. The stalks 

 had been cut off after the manner of cutworms, but lower down and 

 nearer the seed kernel. Cutworms were present in one case only, and 

 the injury appeared to be due, in large part at least, to the beetles. 

 In both cases the land had been treated with barnyard manure, and 

 in this the larvae probably bred, as is the case with Ligyrus. 



The species ranges from Maine to Texas, but is rarely found in Illinois. 

 It is more common in the Eastern States. 



THE LEAF-CHAFERS. 



(Scarabceidce, in part.) 



The most important group of the leaf-chafers, the common June- 

 bugs or white-grubs, has already been treated herein. Three other 

 species remain to be considered among the unimportant corn insects. 



The Scaly June-bug. 

 Lachnosterna lanceolata Say. 



This curious June-bug is quite rare in Illinois, having been taken 

 by us but once in the central and once in the southern part of the state. 

 It is more common in the West and Southwest, and has been recorded 

 from New Mexico, Texas, Kansas, and Colorado. In New Mexico the 

 beetle was brought to Cockerellf with the statement that it injured corn 

 by eating the growing cob. In Texas it often occurs in large swarms, 

 cutting off the young cotton plants over considerable areas. It differs 

 from all our other June-bugs in having a sparse covering of minute 

 whitish scales, giving it an ashy gray and speckled appearance. 



The Rose-chafer. 

 Macrodactylus subspinosus Fabr. 



The rose-chafer is an abundant and destructive pest in the United 

 States and Canada in the region north of a line from Virginia to Col- 

 orado, and including Illinois. Its favorite food plants are rose, grape, 

 blackberry, raspberry, etc., but when excessively abundant it often 



*Rep. Maine Agr. Exper. Station, 1891, p. 199. 

 tBull. 15, N. Mex. Agr. Exper. Station, p. 69. 



