Dixidae

Corrêa, Caio Cezar Dias, Scarpa, Priscila Luiza, Pinho, Luiz Carlos & Gil-Azevedo, Leonardo Henrique, 2024, Three New Species Of Dixella Dyar & Shannon (Diptera: Dixidae) From Santa Catarina, Brazil, Zootaxa 5433 (3), pp. 321-338 : 335

Key to the adult Dixidae of southern Brazil

1. Wings with distinct spots in all cells......................................................... Dixella trinitensis

- Wings without spots or with only a faint spot at crossvein r-m.................................................. 2

2. Thorax (lateral view) with black stripe on dorsal portion and yellow on basal portion....................... Dixella limai

- Thorax (lateral view) brown ( Fig. 2A ; 7C ), or yellow with pale brown spot on katepisternum ( Fig. 5D )................. 3

3. Katepisternum yellow with distinct pale brown spot in middle-anterior portion ( Fig. 5D )................... Dixella jailtoi

- Katepisternum uniformly brown ( Fig. 2A ; 7C ).............................................................. 4

4. Male............................................................................................... 5

- Female............................................................................................. 6

5. Gonostylus triangular (lateral view) with stout setae ( Fig. 8A )...................................... Dixella spinosa

- Gonostylus cylindrical without stout setae ( Fig. 3A–E ).......................................... Dixella moultoni

6. Sternite IX with robust wide lateral portion, without projection ( Fig. 9B )............................. Dixella spinosa

- Sternite IX with slender lateral portion and small projection ( Fig. 4B )............................... Dixella moultoni

Figures

FIGURE 2. Dixella moultoni sp. nov. (A)—♂, Head and thorax, lateral view; (B)—♂, Head and thorax, dorsal view; (C)—♂, Wing; (D)—♀, Wing. Scale bar: (A) 0.2 mm, (B–D) 0.3 mm. Abbreviations: CuA = anterior branch of cubital vein; CuP = posterior branch of cubital vein; M1 = first branch of media; M2 = second branch of media; M3+4 = third and fourth branch of media; m-m = medial crossvein; R1 = anterior branch of radius; R2 = upper branch of second branch of radius; R3 = lower branch of second branch of radius; R2+3 = second branch of radius; R 4+5 = third branch of radius; r-m = radialmedial crossvein; Rs = radial sector; Sc = subcostal vein.

FIGURE 3. Dixella moultoni sp. nov., male terminalia: (A, D)—Dorsal view; (B)—Ventral view; (C)—Lateral view; (E)— Gonocoxite and gonostylus, dorsal view; (F)—Tergite X, dorsal view; (G)—Paramere, lateral view; (H)—Aedeagus, dorsal view. Scale bar: (A–C) 0.1 mm, (D, F) 0.05 mm, (E, G–H) 0.03 mm. Abbreviations: aed = aedeagus; ap lob = apical gonocoxal lobe; gon ap = gonocoxal apodeme; goncx = gonocoxite; gonst = gonostylus; par = paramere.

FIGURE 4. Dixella moultoni sp. nov., female terminalia: (A)—Ventral view; (B)—Sternite IX; (C)—Cercus and segment X, ventral view. The black and red arrows in Fig. B highlight the medial and lateral projections, respectively. Scale bar: (A) 0.1 mm, (B–C) 0.04 mm. Abbreviations: cer = cercus; seg X = segment X.

FIGURE 5. Dixella jailtoi sp. nov., male: (A)—Habitus; (B)—Head and thorax, dorsal view; (C)—Antenna; (D)—Head and thorax, lateral view; (E)—Wing. Scale bar: (A) 0.7 mm, (B–C) 0.2 mm, (D–E) 0.3 mm.

FIGURE 7. Dixella spinosa sp. nov. (A)—♂, Head, dorsal view; (B)—♂, Antenna; (C)—♂, Thorax, lateral view; (D)—♂, Legs, lateral view; (E)—♂, Wing; (F)—♀, Wing. Scale bar: (A, C) 0.2 mm, (B) 0.3 mm, (D) 1 mm, (E–F) 0.5 mm.

FIGURE 8. Dixella spinosa sp. nov., male terminalia: (A)—Dorsal view; (B)—Tergite X, dorsal view. Scale bar: (A) 0.05 mm, (B) 0.03 mm Abbreviations: aed = aedeagus; ap lob = apical gonocoxal lobe; gon ap = gonocoxal apodeme; goncx = gonocoxite; gonst = gonostylus; par = paramere.

FIGURE 9. Dixella spinosa sp. nov., female terminalia: (A)—Ventral view; (B)—Sternite IX; (C)—Cercus and segment X, ventral view. Scale bar: (A) 0.1 mm, (B–C) 0.04 mm. Abbreviations: cer = cercus; seg X = segment X.