89 



Fig. 5. — Octotoma plicatu- 

 la: beetle — about seven 

 times natural size (orig- 

 inal). 



oblong holes in the leaves. It is somewhat remarkal)le that the food 



habits of this species had been overlooked, as far as pul)lished records 



go, until that time, considering that the insect is widely distri])uted and 



frequently found in large numbers. The plant 



has a still wider distribution than the beetle, which 



is proved by failure to find it upon this plant in 



Michigan and in central and southern Florida, as 



well as in other localities. Even in the vicinity of 



the District of Columl)ia the species is local and 



not to be found wherever its food plant occurs. 



May 25, 1879, the habits of this species were 

 first observed by Mr. Schwarz at Columbus, Tex. 

 It was noticed that a pupa was always to be found 

 in a pocket adjoining the midrib. The beetle feeds 

 also on the plant. The mines consist of several 

 sinuous branches starting from the midrib, these 

 branches being of varjdng length and shape. At 

 the end toward the base of the leaf therS is usually an oblong, or 

 nearly oblong, blackish spot, presumably where the (igg has been 

 deposited and where the excrements of the larvte collect. 



Octotoma marginicollis Horn. 



The perfect beetles were found by Messrs. Hubbard and Schwarz in 

 great numbers riddling the entire foliage of certain small ash trees in 

 Madera Canyon, Sta. Rita Mountains, in southern Arizona, during the 

 months of May and June. Neither eggs, larvae, nor larval mines were 

 seen on the trees at this season, and it would seem that the real food 

 plant of the species is a vine or some other plant which makes its 

 appearance onl}^ after the beginning of the rainy season toward the 

 end of July or in August. 



Stenopodius flavidus Horn. 



From various structural details of this genus. Dr. Horn suspected 

 that the habits of the only species would prove to be subaquatic. 

 While nothing definite has been ascertained regarding the larval habits, 

 the imagos have been found in various localities remote from any water, 

 and under conditions which strongly suggest the larval food plant. 

 Near Brownsville, Tex., Mr. Townsend and Mr. Schwarz found a 

 number of specimens on a malvaceous plant which appears to belong 

 to the genus Abutilon. 



