256 Journal of Agricultural Research voi. iv. No. 3 



ber over ten. The species attacking sugar cane belong to the group 

 having three rostral carinas and are to be separated as follows : 



Classification of sugar-cane species and varieties of Diaprepes 



I. Beak with three rostral carinae but not otherwise rugose; first ftmicular joint very 



much smaller than second; densely squamose, more or less denuded in vittae. 

 Prothorax not conspicuously transverse, usually a little longer than wide; vibris- 



sae distinct; body with a lateral yellow or pink vitta spengleri Linnaeus. 



la. Median rostral carina with fovea near apex; elytra without denuded inter- 

 vals; undersides evenly pubescent; pubescence consisting principally of 



flat scales variety marginatus Olivier. 



lb. Median rostral carina without fovea but with transverse carina at same point 

 connecting with the lateral carinae; elytra with denuded intervals; pubes- 

 cence throughout consisting of flat and upright scales. 

 2a. Elytra with only a single row of punctures between the two humeral 

 denuded intervals. 



3a. Fifth interval denuded at base variety comma Boheman. 



3b. Fifth interval denuded at base, and third on disk. 



variety spengleri Linnaeus. 



3c. Third and fifth inter\'als denuded at base . variety abbreviatus Olivier. 



3d. Third to tenth intervals denuded. .. .variety denudatus, new variety. 



2b. Elytra with two rows of punctures between the two humeral denuded 



intervals; third and fifth intervals denuded at base. 



\axi(tty festivus Fabricius. 



II. Beak with three rostral carinae and closely recticulately rugose; first funicular 



joint very nearly as long as second; sparsely squamose famelicus Olivier. 



DI.\PREPES SPENGLERI LINNAEUS 



No species hitherto studied by the writer has shown such a wide range 

 of variations in colors and markings as Diaprepes spengleri Linnaeus. 

 The two sexes differ so much in shape that the male of one variety and 

 the female of another would easily pass as very distinct species. The 

 structural and sculptural differences, however, are exceedingly minute, 

 and the large series of specimens from Porto Rico, Barbados, and the 

 intermediate islands shows that they must all be one species. 



The following characters are common to all forms of the species and 

 are therefore of specific weight in comparing this species with others in 

 the genus: 



Beak tricarinate, with indications of a transverse carina near apex; nasal plate 

 emarginate, triangular. Antennal scrobes arcuate, passing immediately beneath the 

 eye; scape elongate, clavate; funicle with second joint longer than first, third joint a 

 little longer than the following, which are slightly longer than wide and subequal; 

 club elongate, pointed, and very finely pubescent. Prothorax very irregularly con- 

 fluently punctm-ed, sparsely pubescent above, laterally densely vittate; truncate at 

 apex, with distinct ocular vibrissae. Scutellum subquadrate, rounded behind. 

 Elytral striae confused from sixth to sides. Elytra of female acute and somewhat 

 sinuate on margin behind; elytra of male less acute, with margin convex. Last 

 ventral segment of female triangular, of male broadly rounded behind. Tibiae with 

 a few small denticles. 



