89 



oblong- holes in the leaves. It is somewhat remarkable that the food 



habits of this species had been overlooked, as far as published records 



go, until that time, considering that the insect is widely distributed 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 thi.s plant in 



Michigan and in central and southern Florida, as 



well as in other localities. Even in the vicinity of 



the District of Columbia the species is local and 



not to ])e found wherever its food plant occurs. 



Ma}" 25, 1879, the habits of this species were 

 first observed l)y Mr. Schwarz at Columbus, Tex. 

 It was noticed that a pupa was alwa3's to be found 

 in a pocket adjoining the midrib. The beetle feeds 

 also on the plant. The mines consist of several 

 sinuous ])ranches starting from the midrib, these 

 branches being of var3dng length and shape. At 

 the end toward the l)ase of the leaf there is usually an oblong, or 

 nearly oblong, blackish spot, presumably where the egg has been 

 deposited and where the excrements of the larva* collect. 



OCTOTOMA MARGINICOLLIS JToi'n. -— 



The perfect ])eetles were found by Messrs. Hul)l>ard 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, larvfe, 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 only after the beginning of the rainy season toward the 

 end of July or in August. 



Fig. ^.—Ortotomn pUcatu- 

 la: beetle — about seven 

 times natural sine (orig- 

 inal). 



Stenopodius flavidus Horn. 



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

 that the habits of the onl}' 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 an}^ water, 

 and under conditions which strongl}^ 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. 



