Pseudogaurax Malloch, 1915

Marques, Carla De Oliveira, Riccardi, Paula Raile & Ale-Rocha, Rosaly, 2022, New records and species of Pseudogaurax Malloch, 1915 (Diptera: Chloropidae) from the Amazon basin, Zootaxa 5200 (6), pp. 501-524 : 502-503

Pseudogaurax Malloch, 1915

Type species: Gaurax anchora Loew, 1866 (monotypy).

Pseudogaurax Malloch, 1915: 159 ; Sabrosky et al., 1941: 762 (checklist of the Chloropidae genera worldwide); 1945: 457-459 (catalog); 1949: 34 (key); 1966: 118-121 (key); 1989: 464-465 (key); 1990: 457-459 (key); Sabrosky & Paganelli, 1984: 81.29-81.30 (catalog); Seguy, 1951: 307 (catalog); Cogan, 1977: 119 (key); Ismay, 1987: 593-602 (key); Wheeler, 2010: 1146 (key to genera); Nartshuk, 2012: 21 (checklist of the Chloropidae genera worldwide); Cherian, 2013: 204 (key).

Pseudogaurax Duda, 1930: 86 , preoccupied by Malloch, 1915; Sabrosky, 1945: 458 (synonymy and homonymy). Type species: Gaurax interruptus Becker, 1912 (monotypy).

Mimogaurax Hall, 1937: 257 , new designation of Pseudogaurax Duda, 1930 ; Sabrosky, 1945: 458 (synonymy). Type species: Gaurax interruptus Becker, 1912 (monotypy).

Generic diagnosis. Usually stout species, body length 2.0–4.0 mm; ground color predominantly yellow; frons not projected forwards; ocellar triangle shiny, triangular with the lateral margins straight, variable in length; ocellar tubercle black; short upright ocellar setae; long postocellar setae convergent or cruciate; 6 or more short, reclinate fronto-orbital setae; eyes with short, medium to heavy pale pubescence; facial carina indistinct; gena narrow ( Fig. 44 ) to linear ( Fig.18 ); postpedicel usually short and round, with arista inserted apicodorsally; palpi and mouthparts short; scutum with a variety of thoracic coloration patterns; scutellum triangular, variable in length; apical scutellar setae approximated at the base; 1 + 1–2 notopleural setae; wing hyaline; first and second costal sectors about the same length; R 4+5 and M 1 parallel; wing anal lobe developed; male femoral organ absent; hind femur more or less enlarged; tibial organ oval; male cerci not fused mesally; surstylus long and flat; hypandrium closed; distiphallus striate; remnant of the sixth abdominal sternite present; female terminalia telescopic, with cercus narrow and long.

Remark. Some species of Pseudogaurax and Gaurax can be considered morphologically similar, making differentiation between those taxa difficult in some cases (Cogan, 1987; Ismay & Ang, 2019). The species described in this paper were classified as Pseudogaurax which have a combination of characters based on Ismay et al. (2021).

Key to the adult Brazilian species of Pseudogaurax Malloch, 1915

(modified from Sabrosky, 1966)

1 Scutum dorsally blackish, without dorsal stripes; postpronotal lobe yellow; scutellum yellow without dark markings ( Fig. 9 ); ocellar triangle dark, reaching ¾ of frons; legs yellow except fore tibia....... P. trabeatus (Duda) [ Brazil: Santa Catarina]

- Scutum background yellow, with or without dorsal stripes; without the above combination........................... 2

2 Scutum completely yellow; ocellar triangle, pleuron and legs completely yellow; arista brown, sparsely pilose........................................................................................... P. rufus (Duda) [“ Brazil ”]

- Scutum with dorsal stripes brownish to black............................................................... 3

3 Scutum with one central longitudinal dark stripe (acrostichal); ocellar triangle yellow............................... 4

- Scutum with more than the acrostichal dark stripe; ocellar triangle variable....................................... 7

4 Scutellum without marks............................................................................... 5

- Scutellum with a brown to dark brown mark............................................................... 6

5 Legs completely yellow; wide acrostichal stripe, reaching the anterior margin of scutum ( Fig. 5 ); pleuron yellow................................................. P. nigrolineatus (Enderlein) [ Brazil: Paraná, Rio de Janeiro, Santa Catarina]

- Fore tibia with a brown dorsal stripe; hind tibia with a longitudinal brown stripe; tarsi brown apically; acrostichal stripe narrow, not reaching the anterior margin of scutum ( Fig. 1 ); anepisternum with an oval black mark..................................................................... P. cingulatus Sabrosky [ Brazil: Rio Grande do Sul, Roraima, São Paulo]

6 Scutal acrostichal stripe narrow; scutellum with a wide longitudinal stripe, covering about 2/3 of the width of the scutellum and wider than the acrostichal stripe ( Fig. 3 ); intra-alar region without a mark; fore tibia and tarsus brown......................................................... P. longilineatus Sabrosky [ Brazil: Ceará, Minas Gerais, Pará, Rio de Janeiro]

- Scutal acrostichal stripe narrow anteriorly, widening at the posterior apical portion; brown mark in the intra-alar postsutural region; scutellum with a V-shaped dark mark ( Figs.8 ; 74 ); all tibiae and apical tarsomeres dark ( Fig. 72 )............................................................................ P. tibialis (Malloch) [ Argentina; Brazil: Maranhão]

7 Scutum with two to three longitudinal stripes fused posteriorly ( Figs. 4 ; 16; 17 ); scutellum dark, at least mesally; arista usually with dark long pilosity................................................................................. 8

- Scutum with three longitudinal stripes separated posteriorly ( Figs. 7; 10 ); arista with sparse pilosity.................. 10

8 Scutum with two wide longitudinal stripes, sometimes with a thin acrostichal stripe; ocellar triangle yellow; anepisternum with a dark mark.................................................... P. luciscens (Enderlein) [ Brazil: Santa Catarina]

- Scutum with three longitudinal stripes about the same width................................................... 9

9 Anterior apex of the lateral scutal stripe extending to below the postpronotum; intra-alar region without marks ( Fig. 17 ); arista sparsely pubescent; the distal 1/3 of tibiae yellow; fore tarsus brownish; ocellar triangle yellow; postpedicel round.......................................................................... P. tridens Sabrosky [ Brazil: Santa Catarina]

- Anterior apex of the lateral scutal stripe not reaching below the postpronotum; intra-alar region with a thin stripe ( Figs. 16 ; 56 ); arista densely pubescent ( Fig. 55 ); all tibiae dark brown ( Fig. 54 ); ocellar triangle dark brown; postpedicel expanded at the insertion of arista........................................ P. poseidoni sp. nov. [ Brazil: Amazonas; French Guiana]

10 Scutellum without marks.............................................................................. 11

- Scutellum with dark marks............................................................................ 16

11 Scutum with one complete acrostichal longitudinal stripe, color variable; dorsocentral stripes, if present, not discontinuous at the transverse suture................................................................................. 12

- Scutum with a pair of acrostichal longitudinal stripes; dorsocentral stripes discontinuous at the transverse suture ( Fig. 6 ).. 14

12 Scutum with a wide acrostichal stripe, about half of basal width of the scutellum; ocellar triangle yellow.............. 13

- Scutum with a narrow acrostichal stripe; dorsocentral stripe as wide as the acrostichal stripe; intra-alar stripe absent ( Figs. 10 ; 80 ); anepisternum with a round black mark; fore and hind tibiae infuscated brown ( Fig. 78 )................................. P. trilineatus (Becker) [ Brazil: Amazonas, Maranhao, Mato Grosso do Sul, Rondônia, Roraima; Nicaragua; Paraguay]

13 Scutal stripes black; dorsocentral stripe about half as wide as the acrostichal stripe; intra-alar stripe restricted to the postsutural area ( Fig. 7 ); ocellar triangle reaching apex of frons........... P. testaceus (Enderlein) [ Brazil: Roraima, Santa Catarina]

- Scutal stripes dark yellow ( Fig. 11 ); legs pale yellow, except the dark central half of the hind tibia; ocellar triangle reaching 3/4 to apex of frons...................................................... P. idiogenes Wheeler [ Brazil: São Paulo]

14 Scutal stripes dark yellow to light brown; a pair of triangular small marks on the anterior half of scutum ( Figs. 2 ; 20 ); legs completely yellow ( Fig. 18 )........................................ P. flaviscutellatus sp. nov. [ Brazil: Amazonas]

- Scutal stripes dark brown to black; scutum without a pair of triangular marks; legs partly brown..................... 15

15 Fore tibia, mid tibia, fore tarsus and distal part of the hind tarsus dark brown; abdomen with tergites 2–5 dark, and a V-shaped yellow area between tergites 2 and 3................................... P. interruptus (Becker) [“ Brazil ”: Maranhão]

- All tibiae and fore tarsus dark brown ( Fig. 61A ); abdomen with a longitudinal yellow stripe on tergites 2–5 ( Fig. 6 ; 63 ); anepisternum with an oval black mark....................................................................................... P. souzalopesi Sabrosky [ Brazil: Acre, Amazonas, Pará, Rondonia, Roraima; French Guiana; Panama; Peru]

16 Scutum with a pair of acrostichal longitudinal black stripes; scutellum with a mesal triangular black stripe, reaching the apex of the scutellum ( Figs. 13 ; 39 ); anepisternum with an oval black mark; all tibiae and fore tarsus dark brown.................................... P. longitriangularis sp. nov. [ Brazil: Amazonas, Acre, Maranhão, Rondônia, Roraima, Tocantins]

- Scutum with a wide acrostichal black stripe, about half of basal width of scutellum; scutellum, legs and pleuron variable.. 17

17 Scutellum with a mesal triangular black stripe, not reaching apex of scutellum ( Figs. 13 ; 30 ); anepisternum and katepisternum with a large black mark; legs yellow, except all tibiae ( Fig. 28 ); ocellar triangle dark brown, not reaching apex of frons ( Fig. 29 )............................................... P. infulatus sp. nov. [ Brazil: Amazonas, Pará; French Guiana]

- Scutal intra-alar longitudinal stripe absent; scutellar stripe with lateral margins parallel, reaching apex of scutellum...... 18

18 Scutal longitudinal stripes dark yellow to light brown; scutellum as long as wide, with a dark yellow to light brown stripe ( Figs. 14 ; 46 )...................................................... P. pallidus sp. nov. [ Brazil: Amazonas, Roraima]

- Scutal longitudinal stripes dark brown to black; scutellum longer than wide, with a dark brown to black stripe ( Fig. 15 )................................................................... P. plaumanni Sabrosky [ Brazil: Santa Catarina]

Figures

FIGURES 44–48. Male holotype of Pseudogaurax pallidus sp. nov., external morphology. 44, habitus, lateral; 45, head, front view; 46, thorax, dorsal view; 47, adomen and sub-scutellum, posterior view; 48, hind tibia, posterior view (orange yellow oval area indicating location of tibial organ). Scale bars: Fig. 44 = 1.0 mm; Figs 45–48 = 0.3 mm.

FIGURES 18–22. Male holotype of Pseudogaurax flaviscutellatus sp. nov., external morphology. 18, habitus lateral; 19, head, frontal view; 20, thorax, dorsal view; 21, abdomen and sub-scutellum, posterior view; 22, hind tibia, posterior view (red bands indicating location of tibial organ). Scale bars: Fig. 18= 0.5 mm; Figs 19–22 = 0.3 mm.

FIGURES 1–10. Thorax in dorsal view of Brazilian species of Pseudogaurax. 1, P. cingulatus Sabrosky, 1966 (modified from Sabrosky (1966)); 2, P. flaviscutellatus sp. nov.; 3, P. longilineatus Sabrosky, 1949; 4, P. luciscens (Enderlein, 1911); 5, P. nigrolineatus (Enderlein, 1911); 6, P. souzalopesi Sabrosky, 1989; 7, P. testaceus (Enderlein, 1911) (modified from Sabrosky (1966)); 8, P. tibialis Malloch, 1934; 9, P. trabeatus (Enderlein, 1911) (modified from Sabrosky (1966)); 10. P. trilineatus (Duda, 1930). Scale bars = 0.3 mm.

FIGURES 72–75. Male holotype of Pseudogaraurax tibialis Malloch, 1934, external morphology (photographs copyright ©TrusteesoftheNaturalHistoryMuseum, used with permission). 72, habitus, lateral; 73, habitus, dorsal; 74, thorax, dorsal view; 75, original holotype labels. Scale bars: Figs. 72–74 = 0.5 mm.

FIGURES 11–17. Thorax in dorsal view of Brazilian species of Pseudogaurax. 11, P. idiogenes Wheeler, 2009; 12, P. infulatus sp. nov.; 13. P. longitriangularis sp. nov.; 14. P. pallidus sp. nov.; 15, P. plaumani Sabrosky, 1966; 16, P. poseidoni sp. nov.; 17, P. tridens Sabrosky, 1966. Scale bars = 0.3 mm. Abbreviations: ac, acrostichal; dc, dorsocentral; in, intra-alar.

FIGURES 54–58. Pseudogaurax poseidoni sp. nov. external morphology. 54, habitus, lateral; 55, head, front view; 56, thorax, dorsal view; 57, Sub-scutellum, posterior view; 58, hind tibia, posterior view (orange yellow oval area indicating location of tibial organ). Scale bars: Fig. 54 = 1.0 mm; Figs. 55–58 = 0.3 mm.

FIGURES 78–83. Pseudogaurax trilineatus (Duda, 1930) (specimen identified by Curtis W. Sabrosky), external morphology. 78, habitus, lateral; 79, head, front view; 80, thorax, dorsal view; 81, abdomen and sub-scutellum, posterodorsal view; 82, hind tibia, posterior view (pale yellow oval area indicating location of tibial organ); 83, original label. Scale bars: Fig. 78 = 0.5 mm; Figs. 79–82 = 0.3 mm.

FIGURES 61–66. Male holotype of Pseudogaurax souzalopesi Sabrosky, 1989, external morphology. 61, habitus, lateral; 62, head, front view; 63, thorax, dorsal view; 64, abdomen and sub-scutellum, posterior view. 65–66, original holotype labels (Figures kindly provided by Dr. Jung W. Kim, 2018 USNM).

FIGURES 37–41. Female holotype of Pseudogaurax longitriangularis sp. nov., external morphology. 37, habitus, lateral; 38, head, front view. 39, thorax, dorsal view; 40, sub-scutellum, posterior view; 41, hind tibia, posterior view (pale yellow oval area indicating location of tibial organ). Scale bars: Fig. 37 = 1.0 mm; Figs 38–41 = 0.3 mm.

FIGURES 28–32. Female paratype of Pseudogaurax infulatus sp. nov., external morphology. 28, habitus, lateral; 29, head, front view. 30–32: Male holotype. 30, thorax, dorsal view; 31, sub-scutellum, posterior view; 32, hind tibia, posterior view (whitish oval area indicating location of tibial organ). Scale bars: Fig. 28 = 1.0 mm; Figs 29–32 = 0.3 mm.