96 THE NORTH AMERICAN SPECIES OF DROSOPHILA. 



Rhode Island (C. W. Johnson); New York, New York; Bloomington, 

 Indiana (F. Payne); Plummer's Island, Maryland (R. C. Shannon); 

 District of Columbia (Loew collection); Dead Run, Virginia (R. C. Shan- 

 non); North Carolina (U. S. Nat. Mus. coll.); Macon, Georgia (G. L. 

 Carver); Kushla, Alabama; Helena, Arkansas (H. S. Barber); Bethesda 

 (R. H. Hutchison), St. Louis (J. F. Abbott), Missouri. 



This is a fruit-eating form. I have bred it from banana and potato. 

 In many places in the Eastern States it is the commonest of the woods 

 species. 



The eggs have two filaments. The chromosomes, reported by Metz, 

 are described on page 39. 



Drosophila robusta Sturtevant. 1916. Ann. Ent. Soc. America, 9, 331. 



c?", 9 . Arista with about six branches above and three below. Antennse dark brown, 

 second joint pollinose distally. Front over one-third width of head, wider above; dark 

 coflfee-brown, orbits and triangle slightly grayish pollinose. Second orbital fine, about 

 one-fourth length of other two. Second oral bristle not quite one-half size of first. More 

 than ohe prominent bristle on each palpus. Carina broad, very shghtly sulcate; face 

 somewhat shining, brown. Cheeks brown, their greatest width scarcely one-sixth greatest 

 diameter of eyes. Eyes with short pile. 



Acrostichal hairs somewhat irregular, in six to eight rows; no prescutellars. Mesonotum 

 dark dull-brown, with four faint polUnose longitudinal stripes. Scutellum and pleurae 

 dark dullibrown. Legs pale brown; first coxae blackish brown beneath, with a whitish 

 polUnose spot between them. Apical and preapical bristles on first and second tibiae, pre- 

 apicals on third. 



Abdomen grayish brown, each segment with a very broad dark-brown fascia on each 

 side; these fasciae often nearly or quite meet in the mid-dorsal hne. 



Wings clear, veins brown, subterminal part of first vein very dark. Costal index about 

 4.0; fourth-vein index about 1.6; 5x index about 1.2; 4c index about 0.7. 



Length of body 2.5 mm.; wing 2.7 nmi. 



Specimens examined: Hanover, New Hampshire; Woods Hole, Massa- 

 chusetts; Ithaca (S. W. Frost), Cold Spring Harbor (C. W. Metz), Staten 

 Island (F. Schrader), New York; Cabin John Bridge, Maryland (R. C. 

 Shannon); Falls Church, Virginia (N. Banks); Kushla, Alabama (type 

 material); Helena, Arkansas (H. S. Barber). 



This species is a fruit eater. I have bred it from banana, tomato, and 

 potato. Nearly four weeks are required for its development. 



The eggs have four filaments. The chromosomes, reported by Metz 

 (1916, Amer. Nat., 50), are described on page 39; the mating habits will 

 be found on page 7. The puparium has long anterior spiracles, and super- 

 ficially resembles that of D. immigrans n, sp. on that account. The head 

 is figured on page 25 (fig. 6). 



Drosophila sulcata Sturtevant. 1916. Ann. Ent. Soc. America, 9, 330. 



cf, 9. Arista with about five branches above and two below. Antennae reddish brown, 

 third joint dark. Front over one-third width of head; reddish brown, with a dark-brown 

 ocellar dot. Second orbital about one-fourth other two. Second oral bristle not quite 

 one-half first. Three large bristles on each palpus. Carina prominent, not very broad, 

 distinctly sulcate; face reddish brown. Cheeks reddish brown ; their greatest width about 

 one-fifth greatest diameter of eyes. Eyes with rather short, sparse pile. 



Acrostichal hairs in six rows; no prescutellar bristles. Mesonotum grayish pollinose, 

 with somewhat indefinite and variable reddish-brown interrupted stripes. These markings 

 are easily obscured in imperfect specimens. Scutellum grayish pollinose. Pleurae grayish 

 polUnose, reddish-brown below. Legs, including coxae, pale reddish-brown. Apical and 

 preapical bristles on first and second tibiae, preapicals on third. 



Abdomen grayish, with a dark-brown fascia on each side of each segment, leaving 

 usually only a median dorsal and a posterior gray line. 



