Scaptomyza

Magnacca, Karl N. & O’Grady, Patrick M., 2008, New combinations in Hawaiian Drosophila and Scaptomyza (Diptera: Drosophilidae), Zootaxa 1926, pp. 53-60 : 56-57

Key to the Hawaiian Subgenera and Unplaced Species of Scaptomyza , and Species of Subgenera Engiscaptomyza , Grimshawomyia , and Titanochaeta

1. White longitudinal stripe present on scutellum, anteriorly reaching at least to posterior region of mesono- tum, often extending along entire length of mesonotum; terminal fork of arista deep, each branch equal in length to dorsal rays of arista ............................................................................ subgenus Tantalia Malloch

- Scutellum and mesonotum may be striped or unicolorous, but never with longitudinal white stripe described above; terminal fork of arista not deep, branches less than length of dorsal rays....................... 2

2. Rays of arista short; chaetotaxy (e.g., katepisternal and dorsocentral setae) generally reduced; four rows of acrostichal setulae; two well-developed humeral setae .........................subgenus Exalloscaptomyza Hardy

- Rays of arista elongate; combination of other characters not as above....................................................... 3

3. Either zero or one ventral ray present on arista ......................................................................................... 4

- More than one ventral ray present on arista............................................................................................... 10

4. Eight rows of acrostichal setulae present; female ovipositor sclerotized, may be needle-like and pointed.. ................................................................................................................. subgenus Titanochaeta Knab , 24

- Acrostichal setulae present in two to six rows; female ovipositor fleshy, non-sclerotized, non-dentate.... 5

5. Arista lacking ventral rays........................................................................................................................... 6

- One ventral ray present on arista................................................................................................................. 7

6. Head flattened, longer than high; eyes strongly oblique; strong set of presutural dorsocentral setae present ....................................................................................................................subgenus Rosenwaldia Malloch

- Head nearly square as seen in direct lateral view, lower margin approximately equal in length to the fron- tal margin; enlarged setulae may be present in presutural position, but not strong....................................... ......................................................................................................................subgenus Elmomyza Hackman

7. Two rows of acrostichal setulae present ................................................... subgenus Parascaptomyza Duda

- Number of acrostichal rows varies from four to six.................................................................................... 8

8. Wings with marks over crossveins and at apices of R and M veins. Hawai‘i, Moloka‘i, O‘ahu, Kaua‘i .... ..................................................................................................................................... S. parva (Grimshaw)

- Wings completely hyaline........................................................................................................................... 9

9. Head broader than thorax ................................................................... subgenus Alloscaptomyza Hackman

- Head not broader than thorax. Hawai‘i........................................................................ S. taractica (Hardy)

10. Shining black species, thorax and abdomen polished black; two or three ventral rays present on arista; ocellar triangle large, extending to level of proclinate setae; acrostichal setulae present in four rows; clump of black setae on hind trochanter....................................................... subgenus Bunostoma Malloch

- Mesonotum brown (black in S. totonigra ), sometimes with longitudinal vittae; acrostichal setulae in six to

eight rows; ocellar triangle not enlarged; hind trochanter lacking distinctive black setae........................ 11 11. Second antennal segment sharply pointed apically, extending over base of third segment; wings distinctly infuscated around veins and margins, central portions of cells mostly hyaline ............................................ ........................................................................................................... subgenus Grimshawomyia Hardy , 22 - Second antennal segment not sharply pointed; wings hyaline or evenly smoky....................................... 12

12. Tibiae yellow with two narrow brown bands, fainter on front tibia .............................................................. ..................................................................................................... subgenus Engiscaptomyza Kaneshiro , 17

- Tibiae all yellow, or brown with yellow apices......................................................................................... 13

13. Palpi greatly enlarged, protruding beyond the oral margin. Kaua‘i ......................... S. magnipalpa (Hardy)

- Palpi not enlarged, enclosed within the oral cavity when mouthparts retracted........................................ 14

14. Epandrium with a prominent anteroventral lobe, over half as high (dorsoventrally) as main portion of epandrium; surstyli long and broad, setulose over the concave medial surface (see Figs. 117 c and 211 c in Hardy, 1965).............................................................................................................................................. 15

- Epandrium lacking a prominent lobe; surstyli not broad and medially setulose; mesonotum brown to black; femora dark brown......................................................................................................................... 16

15. Thorax entirely yellow; ventral lobe of epandrium broader at apex than at base. O‘ahu.............................. ......................................................................................................................................... S. vinnula (Hardy)

- Mesonotum and anepisternum rufous, tinged with brown; ventral lobe of epandrium nearly parallel-sided, about as wide at apex as at base. O‘ahu ...................................................................... S. improcera (Hardy)

16. Tibiae all yellow. Moloka‘i .............................................................................................. S. prolixa (Hardy)

- Tibiae brown except narrow bases and apices. Moloka‘i, O‘ahu................................ S. totonigra (Hardy)