Copestylum vagum (Wiedemann, 1830)

Montoya, Augusto León, Parada-Marín, Henry Mauricio & Ramos-Pastrana, Yardany, 2022, Description of a new flower fly species of the Copestylum vagum group (Diptera Syrphidae) from pristine Amazonian rainforests of Colombia and Suriname, Zootaxa 5091 (3), pp. 401-415 : 403-411

The Copestylum vagum species group

Diagnosis (adapted from Thompson 2006 and Ricarte et al. 2015). The C. vagum group can be distinguished from the other Copestylum species groups by: 1) face vittate but not tomentose and with background colour shiny yellow, green, or orange, 2) face not particularly extended, 3) scutum with mixed length pile, not forming distinct layers and most orientated posteriorly, 4) no outstanding, long, thick setae along the rear margin of the scutum, although long pile may be present, 5) apex of the scutellum with a linear depression, 6) calypter dark, brown to black or with brown border, 7) tergum 1 and most of tergum 2 with a pale mark contrasting with the colour of the scutum, scutellum and the rest of the abdomen, and 8) male genitalia with aedeagal hood projecting ventrally from the hypandrium, superior lobe with smooth margins.

Remarks. The new species here described agrees with the diagnostic characters proposed for the C. vagum group, but can easily be recognized within this group by the unique and striking male genitalia, characterized by the epandrium and cercus black; epandrium with a dorsal extension, a novel character among the group, in addition to the surstylus L-shaped, with two pairs of rounded ridges in the dorsal edge, similar to small deer antlers in velvet.

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Additional records of species of the Copestylum vagum group

New distributional records of C. tenorium and C. araceorum are here provided. Copestylum tenorium was exclusively known from Costa Rica and C. araceorum was described from material collected in Costa Rica and Ecuador. Both species are recorded for the first time in the Amazonian rainforest of Colombia.

Adjustments to existing identification keys of the C. vagum species group

The last key of Curran (1930, 1939) covered most of the species included in the C. vagum group. Ricarte et al. (2015) partially reviewed the C. vagum group, providing a key for seven species, of which five were described as new. We provide modifications to the previous keys of the C. vagum group to distinguish C. enriquei sp. nov. from the other eighteen species included in the group. The new key is based on characters provided by Curran (1930, 1939), Thompson (2006), and Ricarte et al. (2015), in addition to some new provided here. Images and information of type specimens of nine species (see material and methods) are available at the AMNH website.

1. Scutellum with a preapical depression..................................................................... 2

- Scutellum without a preapical depression.................... other Copestylum species (couplet 48, p. 3 in Curran 1939)

2. Calypter dark, brown to black or with brown border.......................................................... 3

- Calypter entirely pale, yellow to orange..................... other Copestylum species (couplet 43, p. 3 in Curran 1939)

3. Face with a pale background colour ( Figs 3A–3D in Ricarte et al. 2015); Tergum 1 and anterior part of tergum 2 with a conspicuous pale mark compared to the rest of the abdominal tergites (Fig. 11A in Ricarte et al. 2015)................................................................................................. 4 ( C. vagum species group)

- Face with a dark background colour (Figs 24A–24B in Ricarte et al. 2015); Tergum 1 and anterior part of tergum 2 with a similar colour pattern to the rest of the abdominal tergites (Fig. 29 in Ricarte et al. 2015).............................................................................( C. cinctiventre species group) (to couplet 8 in Ricarte et al 2015)

4. Bristles of the thorax entirely pale; at least metatibiae black to dark-brown, sometimes yellow on basal 1/4 such as in C. enriquei sp. nov. ( Figs 1A, 1D–1E , 3C–D )................................................................. 5

- Bristles of the thorax yellow and black; tibiae entirely orange................................................. 21

5. Scutellum with entire wrinkled fascia basally or with subtriangular, roughened flat areas on each side.................. 6

- Scutellum without such areas............................................................................ 7

6. Scutellum with entire roughened fascia basally; wing extensively microtrichose apically, costal cell microtrichose in apical half, almost all of the cells R4+5 and DM microtrichose............................... C. curiosum ( Curran, 1939) [ Brazil]

- Scutellum with subtriangular, roughened flat areas on each side; wing extensively bare apically, costal cell completely bare, cells R4+5 and DM bare except apical fourth or less.................................. C. circe ( Curran, 1939) [ Brazil]

7. Terga 3–4 with yellow marks or completely black........................................................... 12

- Terga 3–4 green to orange with a narrow, black, apical margin.................................................. 8

8. Thoracic setae black (Fig 10 in Ricarte et al. 2015); mid femora with an entirely dark pile............................ 9

- Thoracic setae orange (Fig 9 in Ricarte et al. 2015); mid femora with at least some pale pile......................... 10

9. Face with central vitta strongly pigmented, shining black ( Fig 3A in Ricarte et al. 2015); pleuron with a U-shaped yellow macula (Fig 5 in Ricarte et al. 2015); femora jet black..................................................................................... C. araceorum Ricarte & Rotheray in Ricarte et al. 2015 [ Colombia, Costa Rica, Ecuador]

- Face with central vitta faintly pigmented black (cf. Fig 3B in Ricarte et al. 2015); pleuron with a W-shaped black macula (Fig 10 in Ricarte et al. 2015); femora dark yellow... C. willistoni Ricarte & Hancock in Ricarte et al. 2015 [ Costa Rica, Trinidad]

10. Eyes more than half as long as high ( Fig 4B in Ricarte et al. 2015); face with central vitta present, even if faint ( Fig 3B in Ricarte et al. 2015)................................. C. cyclops Ricarte & Hancock in Ricarte et al. 2015 [ Costa Rica]

- Eyes less than half as long as high ( Fig 4D in Ricarte et al. 2015); face without central vitta (cf. Fig 3D in Ricarte et al. 2015) .................................................................................................. 11

11. Tibiae jet black; male cerci triangular-shaped (Fig 19A in Ricarte et al. 2015)....................................................................................... C. tigrinum Ricarte & Hancock in Ricarte et al. 2015 [ Trinidad]

- Tibiae dark yellow; male genitalia large, cerci elongate, L-shaped (Fig 17A in Ricarte et al. 2015)................................................................................... C. musicanum ( Curran, 1930) [ Brazil, Suriname]

12. Mesonotum wholly pale pilose on posterior half............................................................ 13

- Mesonotum broadly black pilose in front of scutellum....................................................... 18

13. Gena and face separated by a very broad brown vitta ( Figs 1A, 1C–1D , 3A–B ); scutum orange except for the wide medial vitta, which is dark and metallic, ending before the prescutellar region, with the apical margin M-shaped ( Figs 1B–1C , 3D ; Reemer 2016: 100, Fig. 15, dorsal habitus); tibiae dark-brown, except yellow on basal 1/4 ( Figs 1A, 1D–1E , 3C–D ); epandrium and cercus black ( Figs 2A–2E )............................................. C. enriquei sp. nov. [ Colombia, Suriname]

- Gena and face separated by a narrower brownish vitta; scutum orange, medial vitta with a different pattern; tibiae extensively black; epandrium and cercus orange..................................................................... 14

14. Scutellum black pilose on disc.......................................................................... 15

- Scutellum pale pilose on disc........................................................................... 16

15. Pleuron black-marked; dorsal margin of eyes sloping (Fig. 9 in Ricarte et al. 2015)..................................... C. vagum ( Wiedemann, 1830) [ Brazil, Brazilian Amazon, Colombia, Costa Rica, Guyana, Less Antilles, Peru, Suriname]

- Pleuron without black marks, uniformly yellow and orange; dorsal margin of eyes flattened (Fig. 7 in Ricarte et al. 2015)......................................... C. tenorium Ricarte & Rotheray in Ricarte et al. 2015 [ Colombia, Costa Rica]

16. Gena and face separated by a very broad brownish vitta...................................................... 17

- No brown vitta separating face and gena............. C. brevifacies ( Curran, 1926) [ Argentina, Brazil, Guyana, Suriname]

17. Mesonotum with the median third black; black vitta separating face and gena very wide and of uniform width.................................................................. C. chapadensis ( Curran, 1930) [ Brazil, Brazilian Amazon]

- Mesonotum usually all ferruginous on the disc (if with black vitta it is partly linear); vitta separating face and gena usually narrow, sometimes broad above.................................... C. bequaerti Curran, 1930 [ Guatemala, Mexico]

18. Metatibiae black..................................................................................... 19

- Metatibiae orange................................................... C. flukei ( Curran, 1936) [ Brazil, Colombia]

19. Mesonotum with a large, median black spot before the scutellum, ventral scutellar fringe black....................... 20

- Mesonotum without median black macula anterior to scutellum; ventral scutellar fringe yellow.......................................................................................... C. lanei ( Curran, 1936) [ Brazil, Colombia]

20. Coxae yellow pilose............. C. mocanum ( Curran, 1936) [ Colombia, Brazilian Amazon, Guatemala, Peru, Venezuela]

- Coxae black pilose........................................................... C. rurale ( Curran, 1939) [ Brazil]

21. Face green or yellow, without median black vitta; terga 3−5 entirely black pilose................................................................................... C. virescens ( Williston, 1891) [ Colombia, Costa Rica, Guatemala]

- Face with broad median blackish vitta; terga 3−5 extensively white pilose on basal 1/2...................................................................................................... C. varichaeta ( Curran, 1925) [ Peru]

Figures

FIGURE 1. Copestylum enriquei sp. nov., male, holotype (LEUA–00000035890): A. Head, frontal view; B. Habitus, dorsal view; C. Thorax, dorsal view, detail of maculae and pile patterns on scutum; D. Lateral view, E. Latero-posterior view, detail of male genitalia.

FIGURE 2. Copestylum enriquei sp. nov., male, holotype (LEUA–00000035890). A. Abdomen, lateral view; B. Abdomen, ventral view; C. Whole genitalia including epandrium, cercus, and surstylus, lateral view, detail of the dorsal extension of the epandrium (white arrow); D. Epandrium, dorsal view, detail of the dorsal extension (white arrow); E. Hypandrium, ventral view. Abbreviations used in male genitalia structures are as follows: Ah = Aedeagal hood; Cer = Cercus; Epd = Epandrium; Hyp = Hypandrium; Sa= Surstylar apodeme; Sl= Superior lobe; Sur = Surstyle.

FIGURE 3. Copestylum enriquei sp. nov., female, paratype (RMNH-collection). A. Head, frontal view; B. Head, lateral view, C. Habitus, lateral view; D. Thorax and abdomen, dorsal view.

FIGURE 4. A. Habitat of Copestylum enriquei sp. nov. in a pristine forest at Florencia, Caquetá in Colombia. The specimens were collected using a canopy Malaise trap (Rafael & Gorayeb 1982); B. Geographical distribution map showing the collection localities of Copestylum enriquei sp. nov. in the Amazon rainforest of Colombia and Suriname (Red triangle).