Alavesia, Sinclair & Grimaldi, 2020

Sinclair, Bradley J. & Grimaldi, David A., 2020, Cretaceous diversity of the relict genus Alavesia Waters and Arillo (Diptera: Empidoidea: Atelestidae), American Museum Novitates 2020 (3961), pp. 1-40 : 36

KEY TO MALES OF BURMESE AMBER FOSSIL SPECIES OF ALAVESIA

1. Aristalike stylus greatly lengthened, at least twice length of postpedicel, with apical expansion or flag (fig. 1G, H)......................................................................2

– Aristalike stylus shorter than postpedicel, without modified apex..........................3

2. Palpus narrow and elongate (figs. 9E, 14C); apical aristalike stylus 2 × length of postpedicel; apical flag darkened (figs. 1H, 14B, C)............................................ A. longsistylata

– Palpus flattened and elongate (fig. 9C, D); aristalike stylus more than 2.9 × length of postpedicel; apical flag light colored (figs. 8F, 13D).............................. A. longicornuta , sp. nov.

3. Cell dm very short, crossvein dm-m opposite apex of cell bm (figs. 2B, C, 3C)...............4

– Cell dm longer, crossvein dm-m clearly positioned beyond apex of cell bm..................6

4. M 1+2 strongly arched towards R 4+5 (fig. 2B, C)...........................................5

– M 1+2 gradually arched to wing margin (fig. 3C)..... Alavesia pankowskiorum , sp. nov. [in part]

5. Smaller size (wing length: 0.75 mm); postpedicel slightly curved and gradually tapered apically (fig. 1B).................................................... Alavesia brevipennae , sp. nov.

– Larger size (wing length: 1.1 mm); postpedicel straight and tapered on apical fourth (fig. 1C).. Alavesia myanmarensis

6. M 1+2 and R 4+5 divergent apically (figs. 2D, 3D–F, 4A, B)...................................7

– M 1+2 and R 4+5 nearly parallel apically (figs. 2A, E, 3B)...................................10

7. Wing with distinctly narrowed apex; cell dm long and slender (fig. 4A)...................... Alavesia spinosa , sp. nov.

– Wing with rounded apex; cell dm short and expanded apically (figs. 2D, 3D–F, 4B)..........8

8. Wing less than 1.5 mm (fig. 3D–F); postpedicel narrow lanceolate to narrow triangular (fig. 1I–K).......................................... Alavesia pankowskiorum , sp. nov. [in part]

– Wing more than 1.5 mm (figs. 2D, 4B); postpedicel large and broad (fig. 1D, M).............9

9. Wing length 1.8 mm (fig. 2D)................................. Alavesia lanceolata , sp. nov.

– Wing length 2.1 mm (fig. 4B)...................................... Alavesia zigrasi , sp. nov.

10. Scape longer than pedicel............................................. Alavesia hadroceria

– Scape shorter than pedicel...........................................................11

11. CuA recurved, aligned with apex of cell bm (fig. 2A, E); wing short (less than 2.0 mm), narrow or rounded...........................................................................12

– CuA arched distally, extending beyond cell bm (fig. 3B); wing very long (3.0 mm), narrow and linear.......................................................... Alavesia magna , sp. nov.

12. Wing apex pointed (fig. 2A); postpedicel narrow and fusiform (fig. 1A); stylus length 0.46 × postpedicel....................................................... Alavesia angusta , sp. nov.

– Wing apex broadly rounded (fig. 2E); postpedicel elongate triangle (fig. 1F); stylus length 0.54 × postpedicel...................................................... Alavesia latala , sp. nov.