84 THE NORTH AMERICAN SPECIES OF DROSOPHILA. 



California (L. L. Gardner); San Jose, Costa Rica; Norway (O. L. Mohr); 

 Perth, West Australia (G. Compere); Hilo (H. W. Henshaw), Olaa (W. H. 

 Ashmead), Hawaii. 



I have previously identified this species as D. tripundata Loew. A re- 

 examination of the type specimen of that species, in the Museum of Com- 

 parative Zoology, shows it to belong to the species that I described under 

 the name of D. modesta. Becker (1908, Mitt. zool. Mus. Berlin, 4, 155) 

 recorded D. tripunctata from the Canary Islands, but stated that the de- 

 scription given by Loew was incomplete. He described the branches of 

 the arista, fourth-vein index, eight acrostichal rows, and dull thoracic color. 

 These notes fit the present species, but not all of them apply to the true 

 D. tripunctata. Since D. immigrans occurs in Europe, and is in fact almost 

 if not quite cosmopolitan, it seems probable that it is the species that 

 Becker had. 



I have bred D. immigrans from the following: banana, pineapple, apple, 

 tomato, sour boiled potato, bran mash, graham-flour paste. It is very 

 easilj^ kept in the laboratory on banana agar. It is to be collected about 

 fruit in grocery stores, in tomato patches, and occasionally around fruit 

 exposed in the woods. It is common at Woods Hole and near New York 

 City, but has not appeared in the large series of specimens from Indiana, 

 and is only locally common in the Southern States. I have found only 

 one specimen in Alabama, but it is included in the very small series that I 

 have seen from Daytona and from New Orleans. At San Jose, Costa Rica, 

 I found it very plentiful in the Central Market. The species is curiously 

 rare in collections. I have seen no American specimens collected before 

 1913. These data, in connection with the fact that the species is common 

 about grocery stores and houses, with the cosmopolitan species, suggest 

 that it is an imported form. It will not be surprising if an earlier name, 

 applied in some other region, is discovered. 



The following dates are the earliest ones known to me for this species: 

 1898 or earlier, Hawaii; 1907, Canaries (?); 1912 or earlier, Australia; 

 1913, New York, Massachusetts; 1914, Florida, California; 1915, Costa 

 Rica; 1919, Norway. 



These data suggest that the species may have come from the Pacific region. 

 It evidently is not one of the forms described from Hawaii by Grimshaw, 

 and since it was probably present in the islands at the time his material 

 was collected, it is possible that it was one of the forms that Perkins believed 

 to be introduced. Such species were apparently usually omitted from the 

 treatments given in the Fauna Hawaiiensis. 



The egg of D. immigrans has four filaments. The puparium has anterior 

 spiracles that are nearly half as long as the body of the puparium. 



The single costal bristle is suggestive of Mycodrosopkila, the members 

 of that genus being the only other Drosophilinse known to me that do not 

 have two such bristles. This form is not to be compared with that genus in 

 any other respect, so this similarity must be supposed to be only accidental. 



The chromosomes of D. immigrans have been described by Metz (1916, 

 Amer. Nat., 50; see p. 39 of this paper). The mating habits are described 

 elsewhere (p. 6), as are also certain mutations studied by Metz and Metz 

 and by myself (p. 14). The spermatheca is figured on page 36. 



Drosophila funebris Fabricius. 1787. Mant. Ins., 2, 345, 33 (as Musca). (Plate 2, 



fig. 3.) 

 Musca erythrophthalma Panzer. 1794. Faun. Germ., 17, 24. 



d^, 9 . Arista with about six branches above and four below. Antennae yellow, 

 ftiird joint brown. Front about one-half wddth of head, wider above; j-ellowish brown. 



