252 Forty-fourth Report on the State Museum 



wood, which is then eaten. More than the tender cambium layer has 

 been apparently removed — possibly all of the exposed alburnum, as 

 in the pieces received, the bottom of the wound shows patches of black 

 and dead wood, overgrown at their margins by the new growth that 

 had taken place since the injury was inflicted. 



Another quite different habit of obtaining food has been ascribed 

 to Dynastes by some writer whom we can not now refer to, nor would 

 it, probably, authenticate the statement or give it any claim to con- 

 sideration, if it could be found. The beetle is said to attach itself to 

 a small branch by grasping it between its horns, and twirling 

 its body round and round by a rapid movement of its wings, so 

 tears the bark as to give it the food desired — either the inner bark 

 or, as some suppose, the sap that flows from the laceration. 



Possibly the beetles may be both bark-eaters and sap-suckers. Mr. 

 J. Doll records* of a species of Dynastes observed by him, and of which 

 he " captured over one hundred examples, some fully four inches in 

 length," in Hell's Canon, Arizona, that " they are always found near 

 the tips of branches, where, by means of their projecting thoracic 

 horns, they scrape through the soft bark to cause a flow of sap, 

 which is very sweet, and of this consists their food."f 



In further remark upon the feeding habits of the beetle, Mr. 

 Lugger may be quoted, in giving the water-ash [black ash] Fraxinus 

 samhucifolia as its favorite food-plant. On the shore of eastern 

 Maryland he had attracted the beetle by bruising ash-twigs — a 

 friend from Mexico having informed him that in that country they 

 were so taken {Ent. Amer., loc. ciL). The bruised leaves of this species 

 of ash are well known for the peculiar odor that they give forth ; l)r. 

 Asa Gray has compared it to the scent of elder. 



Variations in Color. 



The different colors occasionally presented in individuals of this 

 species, particularly in the female, has often been remarked upon. 

 In my preceding notice of the insect it is stated : " One example in 

 my collection has the thorax black, while in another both the thorax" 

 and the wing-covers are very dark brown. A male before me has 

 the thorax of the normal color, while the elytra are dark brown, 

 slightly mottled with paler brown." 



Some have thought these darker colors to be the result of " greas- 

 l ng," but Dr. Hamilton seems to have found the proper explanation. 



♦ Bulletin of the Brooklyn Entomological Society, vii, 1885, p. 121. 



t This species is thought by Dr. Horn to be Dynastes Gh'antii, described by him in 

 Trans. Amer. Entomolog. Soc, iii, 1870, p. 78, as a variety of 1). Tityus : it is so cited in the 

 Fifth Rept. Ins. N. T., 1889, p. 227, but is now regarded as a valid species. 



