Phasia pusilla

Sun, Xuekui & Marshall, Stephen A., 2003, Systematics of Phasia Latreille (Diptera: Tachinidae), Zootaxa 276 (1), pp. 1-320 : 114-116

3.5. The Phasia pusilla species­group

The Phasia pusilla species­group includes all the species previously placed in the subgenus Hyalomyia (sensu Herting 1984) . Although the group is easily diagnosed as follows, it lacks defining characters and some species in this group are probably more closely related to the Phasia argentifrons species­group than to other species of the Phasia pusilla species­group.

Diagnosis: Head spherical; fronto­orbital plate entirely, not swollen; dorsal facets of eye larger than ventral facets. Parafacial bare; lower margin of face projecting, visible in profile. Thorax black, shining or thinly pruinose; one katepisternal seta. Scutellum black, with two pairs of marginal setae; basicosta brown to black. Wing always hyaline; R 4+5 with a long petiole, usually more than 0.25 times as long as preceding section of R 4+5; M meeting R 4+5 at right angle. Abdomen black, subovate, with pruinosity; tergite IV and V with distinct hair spots. Male syncercus notched posteriorly; surstylus longer than cercus; phallus haired.

Key to species of Phasia pusilla species group

(The males of Phasia emdeni , Phasia faceta , Phasia girschneri , Phasia noskiewiczi and Phasia siberica are unknown. Unrevised species (Neotropical) are marked with an asterisk).

1. Hind femur strongly arched .......................................* P. curvipes ( Aldrich, 1934) ♂ ♀

­ Hind femur not arched .................................................................................................. 2

2. Hind tibia strongly arched, shorter than hind femur; presutural supraalar seta absent; sternite VI of female extremely long, longer than the total length of the previous sternites. ............................................................................ P. punctigera ( Townsend, 1891) ♂ ♀

­ Hind tibia straight or slightly arched, as long as hind femur; presutural supraalar seta usually present; sternite VI of female shorter than the total length of other sternites... 3

3. Male .............................................................................................................................. 4

­ Female ........................................................................................................................ 12

4. Eyes separated by a distance equal to or greater than the width of ocellar triangle .....5

­ Eyes separated by a distance less than the width of ocellar triangle ............................ 7

5. Abdomen slender, tergite IV with 8­10 rows of hairs; body size 6.5­ 8.5 mm; Nearctic species ................................................................................ P. robusta ( Brooks, 1945) ♂

­ Abdomen spherical, tergite IV with 4­6 rows of hairs; body size 3.0­ 5.5 mm; Palaearctic or Oriental species ................................................................................................... 6

6. Syncercus deeply notched posteriorly, almost semi­circular; outer angles rounded; distiphallus with a posterior fan­like lobe, and regular saw teeth........................................ .......................................................................................... P. indica ( Mesnil, 1953) ♂

­ Syncercus shallowly notched posteriorly; outer angle acute; distiphallus with marginal irregular saw teeth ....................................... ....... P. mesnili (Draber­Mo ń ko, 1965) ♂

7. Dorsum of syntergite I+II and tergite III matte black, other tergites silky pruinose (strongly contrasting); eyes separated by a distance equal to the diameter of a single ocellus.................................................................. P. venturii (Draber­Mo ń ko, 1965) ♂

­ Dorsum of tergites not as above; eyes separated by a distance wider than a single ocellus, but narrower than the ocellar triangle .................................................................... 8

8. Dorsum of abdomen with a purple shining area P. purpurascens ( Townsend, 1891) ♂

­ Dorsum of abdomen without purple shining area ........................................................ 9

9. Surstylus ball­like ...................................................... P. aldrichii ( Townsend, 1891) ♂

­ Surstylus flattened, or slender .................................................................................... 10

10. Syncercus with posterior notch over 1/2 of length ........... P. pusilla (Meigen, 1924) ♂

­ Syncercus with posterior notch less than 2/5 of length .............................................. 11

11. Phallus without fine hairs dorsally .................................. P. truncata Herting, 1983 ♂

­ Phallus with fine hairs dorsally; distiphallus with sclerotized saw teeth ........................ ........................................................................................ P. pandellei ( Dupuis, 1957) ♂

­ As in P. pandellei but distiphallus membranous ........... P. normalis (Curren, 1927) ♂

12. Sternite VII deeply notched posteriorly ...................................................................... 13

­ Sternite VII not notched posteriorly ........................................................................... 16

13. Sternite VII broad posteriorly in profile, over 1/2 as wide as that of middle ............14

­ Sternite VII narrow posteriorly in profile, less than 1/3 as wide as that of middle .... 15

14. Sternite VII short and broad in profile ............................. P. truncata Herting, 1983 ♀ ­ Sternite VII slender in profile ........................ P. girschneri (Draber­Mo ń ko, 1965) ♀

15. Sternite VII strongly flattened laterally; in ventral view, outer side of posterior half parallel­sided ................................................................. P. pandellei ( Dupuis, 1957) ♀

­ Sternite VII flattened dorsoventrally; in ventral view, narrow at middle, outer side of posterior half arched ........................................... P. emdeni (Draber­Mo ń ko, 1970) ♀

16. Sternite VII bent downward posteriorly ..................................................................... 17

­ Sternite VII straight or bent upward posteriorly ........................................................ 18

17. Sternite VII with a median unsclerotized area ............................................................... ....................................................................... P. noskiewiczi (Draber­Mo ń ko, 1965) ♀

­ Sternite VII without a unsclerotized area ............................ P. pusilla Meigen, 1824 ♀

18. Sternite VII arrow­like posteriorly in ventral view; wrinkles ventrally.......................... ............................................................................. P. mesnili (Draber­Mo ń ko, 1965) ♀

­ Sternite VII as in P. mesnili but smooth ventrally.......... P. normalis (Curren, 1927) ♀

­ Sternite VII not arrow­like posteriorly in ventral view .............................................. 19

19. Dorsum of syntergite I+II, and most part of tergite III matte shining black; sternite VII abruptly and sharply pointed ............................. P. venturii (Draber­Mo ń ko, 1965) ♀

­ Dorsum of tergites not as above; sternite VII gradually narrowed ............................ 20

20.Apex of sternite VII beak­like in profile, basal width half of its length; body length 6.8 mm .......................................................................................... P. robusta ( Brooks, 1945) ♀

­ Apex of sternite VII not beak­like, basal width less than 1/2 of its length; body length 3.5 mm ........................................................................................................................ 21

21. Frontal vitta 6.5 times as wide as fronto­orbital plate anteriorly at level of antenna base ......................................................................................... P. faceta Sun , new species ♀

­ Frontal vitta less than 4 times as wide as fronto­orbital plate anteriorly at level of antenna base ................................................................................................................ 22

22. Sternite VII with distinct micro spines ventrally in posterior 3/5, tubular in ventral view ............................................................................................. P. indica ( Mesnil, 1953) ♀

­ Sternite VII with indistinct spines ventrally, tower­like in ventral view .................... 23

23. Abdomen greyish white pruinose, hair spots indistinct; abdomen spherical, sternite VII short............................................................................ P. aldrichii ( Townsend, 1891) ♀

­ Abdomen greyish yellow pruinose; hair spots very distinct, sternite VII long .......... 24

24. Frontal vitta at base of antennae 2.1 times as wide as fronto­orbital plate anteriorly; Palaearctic species ....................................................... P. siberica Sun , new species ♀

­ Frontal vitta less than 1.5 times as wide as fronto­orbital plate anteriorly; Nearctic species ........................................................................... P. purpurascens ( Townsend, 1891) ♀