Key to the species of Anthomyiidae, Fanniidae and Muscidae from Juan Fernández Archipelago (Chile). (Species marked with an * were not recorded in this study.)

1. Scutellum usually with fine pale cilia ventrally at tip (Fig. 1); if scutellum bare ventrally and frons wider than longer in male, then frons with strong interfrontal setae. Wing usually with A1+CuA2 vein reaching edge of wing (Fig. 2 and 5).................................................................................................. ( Anthomyiidae) 2

- Scutellum without fine pale cilia ventrally at tip. Wing with A1+CuA2 vein not reaching edge of wing................... 5

2. C vein bare on ventral surface (Fig. 6). Male: hind tibia with row of short erect posteroventral setae.................... 3

- C vein ciliated on ventral surface (Fig. 3). Male: hind tibia without a row of short erect posteroventral setae.............. 4

3. First tarsomere of midleg without a brush of long dorsal setae. Hind femur with no more than 6 preapical posteroventral setae restricted to the apical fifth of the surface (Fig. 4)..................................... Delia platura (Meigen, 1826)

- First tarsomere of midleg with a brush of long dorsal setae. Hind femur not as above..... Delia sanctijacobi (Bigot, 1885) *

4. Scutellum with fine pale cilia at tip of ventral surface (Fig. 1). Wing with brown maculae on crossveins r-m and dm-cu (Fig. 2). Male holoptic......................................................... Anthomyia limbinervis (Macquart, 1834)

- Scutellum without fine pale cilia at tip of ventral surface. Wing without maculae on crossveins r-m and dm-cu. Male dichoptic....................................................................... Fucellia tergina (Zetterstedt, 1845) *

5. Vein Sc sinuous, with apical curvature forward toward C vein, making a bigger angle (Fig. 7, white arrow); vein A2 slightly or strongly curved (Fig. 7, black arrow)............................................................ ( Fanniidae) 6

- Vein Sc non-sinuous, without apical curvature forward toward C vein, making a smaller angle; vein A2 straight (Figs. 33–44).......................................................................................... ( Muscidae) 11

6. Vein A2 slightly curved, imaginary extension of anal veins meeting near wing margin. Male and female dichoptic.............................................................................. Euryomma peregrinum (Meigen, 1826) *

- VeinA2 strongly curved, imaginary extension of the anal veins meeting well before the margin of the wing (Fig. 7). Male hol- optic and female dichoptic................................................. Fannia (Robineau-Desvoidy, 1830) 7

7. Hind coxa bare at apex of posterior surface................................................................. 8

- Hind coxa setulose at apex of posterior surface (Fig. 8)....................................................... 10

8. Abdomen not uniformly dark-blue. Male: hind femur with a preapical protuberance on posterior surface, with a row and a hair-

like subapical tuft on posteroventral surface................................................................. 9 - Abdomen uniformly dark-blue (Figs. 16 and 17). Male: hind femur without a preapical protuberance on posteroventral surface, without a row and a hair-like subapical tuft on posteroventral surface.................. Fannia anthracina (Walker, 1836)

9. Male: Fore leg with metatarsus bearing broad leaf-like spine at tip of posterior surface; hind femur with a preapical protuberance on ventral and posteroventral surfaces, with a long hair-like subapical tuft on posteroventral surface (longer than femoral width). Abdomen dark grey with light blue to greyish pruinosity....................... Fannia albitarsis (Stein, 1911) *

- Male: Fore leg with metatarsus without broad leaf-like spine at tip of posterior surface; hind femur with preapical protuberance on posterior surface, with short hair-like subapical tuft on posteroventral surface (shorter than femoral width). Abdomen dark grey................................................................. Fannia punctiventris (Malloch, 1934) *

10. Legs dark brown with yellow joints; hind femur with a row of weak setae on anteroventral surface, only 2–3 stronger near apex. Male: abdomen brown-greyish with syntergite 1+2, tergites 2 and 3 yellow-translucent with median vitta brown............................................................................ Fannia canicularis (Linnaeus, 1761) *

- Legs yellow, except fore femur and tarsomeres dark brown (Fig. 8); hind femur with a row of strong setae on anteroventral surface (setae near the apex are longer) (Fig. 24) Male: abdomen uniformly dark brown (Fig. 21)......... Fannia hennigi sp. n.

11. Labella not reduced (Fig. 41); prestomal teeth not developed.................................................. 12

- Labella reduced (Fig. 11); prestomal teeth developed........................................................ 14

12. General coloration of body not metallic. Vein M strongly curved forward apically. Lower calyptra enlarged, sub-truncate posteriorly with anteromedian angle extended at least to slightly under base of scutellum...... Musca domestica Linnaeus, 1758

- General coloration of body metallic or bluish black not metallic. Lower calyptra glossiform, not extended below base of scutellum. Vein M parallel or very slightly forward-curved apically (Fig. 41).......................................... 13

13. General coloration of body metallic violet blue or green. Gena without strong, upward-directed setae (Figs. 40 and 41). Male: fore femur without a distinct concavity on ventral surface (Fig. 40)............. Psilochaeta chalybea (Wiedemann, 1830)

- General coloration of body not metallic, black or bluish black. Gena with strong, upward-directed setae (Figs. 33 and 34). Male: fore femur with distinct concavity on ventral surface, with two toothed processes near concavity (Fig. 33).............................................................................. Hydrotaea cyaneiventris (Macquart, 1851)

14. Wing with Rs node or base of vein R4+5 ciliated on dorsal surface............................................... 15

- Wing with Rs node or base of vein R4+5 with no cilia on dorsal surface........................................... 16

15. Gena strongly projected; palpus well dilated to apex (Fig. 11)................... Syllimnophora lispomima Hennig, 1955

- Gena not strongly projected; palpus not dilated to apex (Figs. 35 and 36)........... Limnophora patagonica Malloch, 1934

16. Sternite 1 setulose. Katepisternal setae 2+1 (Fig. 9, white arrow)...................... Lispoides insularis Hennig, 1957

- Sternite 1 bare. Katepisternal setae 1+1+1, forming equilateral triangle (Fig. 10, white arrow)........................ 17

17. Postsutural dorsocentral setae 2............................................. Schoenomyzina emdeni Hennig, 1955

- Postsutural dorsocentral setae 3......................................................................... 18

18. Lower and upper calypter with similar length (Fig. 10, black arrow). Frons broad, wider than long.......................................................................................... Notoschoenomyza kuscheli Hennig, 1955

- Lower calypter about twice as long as upper one (Fig. 9, black arrow). Frons not broad, about same length and width................................................................................ Coenosia ignobilis (Stein, 1911) *