Key to species in the Paragrallomyia albibasis complex

1) Cell r 4+5 closed at wing margin (Fig. 55). Anterior half of postpronotal lobe with three to four strong black setae (Figs. 53, 55).............................................................. Paragrallomyia vulpes (Cresson) Costa Rica

- Cell r 4+5 open at wing margin (Fig. 1). Anterior half of postpronotal lobe bare or with a dense row of five or more long black setae............................................................................................... 2

2) Epicephala merging immediately behind ocellar plate, postocellar part of frontal vitta thus short and abruptly tapered to a point anterior to postocellar setae (Figs. 4, 31, 39, 49)............................................................. 3

- Epicephala converging but not immediately merging near the ocellar plate, postocellar part of frontal vitta thus reaching postocellar setae (Figs. 6, 15, 17)............................................................................. 7

3) Frontal vitta with a velvety black spot anterior to ocellar plate (Figs. 31, 39, 49).................................... 4

- Frontal vitta darkened, without rounded black velvety spot (Figs. 4, 20).......................................... 6

4) Epicephalon somewhat elevated above level of fronto-orbital plate (Fig. 49). Copulatory fork with short quadrate inner basal lobes, less than twice as long as wide (Fig. 52)... Paragrallomyia thiemei (Enderlein) Bolivia, Brazil, Colombia, Costa Rica, Ecuador, French Guiana, Guiana, Peru, Venezuela.

- Epicephalon flat, about same level as fronto-orbital plate (Figs. 31, 33). Copulatory fork with long apically rounded inner basal lobes, more than three times as long as wide (Figs. 34, 42)..................................................... 5

5) Rounded black velvety spot on frontal vitta swollen (Fig. 33). Ejaculatory apodeme large, blade wider than sperm pump (Fig. 34)............................................................... Paragrallomyia nodulosa n. sp. Costa Rica

- Rounded black velvety spot on frontal vitta flat (Fig. 41). Ejaculatory apodeme small, sperm pump wider than blade (Fig. 42).................................................................. Paragrallomyia quadrifurca n. sp. Panama

6) Epicephalon somewhat elevated above frontal vitta level (Fig. 20). Copulatory fork with developed inner basal lobes, lobes less than half as long as the posterior ones (Fig. 23)........................... Paragrallomyia colombiana n. sp. Colombia

- Epicephalon flat, about same level as frontal vitta (Fig. 4). Copulatory fork with small quadrate inner basal lobes (Fig. 5)............................................................ Paragrallomyia aequorea n. sp. (male only) Colombia

7) Mid and hind tibiae flattened, sulcus on outer face strongly pronounced and curved (Figs. 24, 37)...................... 8

- Mid and hind tibiae cylindrical or nearly so, sulcus on outer face weak or absent (Figs. 18, 45)....................... 10

8) Frontal vitta brown or dark brown, without black spot anterior to ocellar plate (Fig. 27). Fronto-orbital plate orange brown...................................................... Paragrallomyia ecuadoriensis n. sp. Ecuador. (female only)

- Frontal vitta with a black spot anterior to ocellar plate (Figs. 25, 35). Fronto-orbital plate brown or dark brown........... 9

9) Thorax uniformly blackish. Abdominal tergites dark brown/black. Relatively large, body length 7–8 mm ............................................................................. Paragrallomyia pseudoalbibasis n. sp. Costa Rica

- Thorax brown laterally, black on mesonotum only. Abdominal tergites brown. Relatively small, body length 4–5 mm ............................................................. Paragrallomyia diminuta n. sp. Costa Rica (female only)

10) Frontal vitta orange brown or dark brown, uniformly pigmented (Fig. 15, 17)..................................... 11

- Frontal vitta colour variable, but always with a black spot anterior to ocellar plate................................. 12

11) Frontal vitta and postpronotal lobe orange-brown (Fig. 17). Female cervical sclerite with a white rounded swelling. Paired spermathecal duct stems thin and with spine-like processes on apical half, duct no more than half as wide as one of the paired spermatheca. Paired spermatheca oval and with sparse micro finger-like processes (Fig. 19). Single spermatheca broad basally, tapered apically and covered by small spine-like appendices........ Paragrallomyia citrina n. sp. Costa Rica (female only)

- Frontal vitta and postpronotal lobe dark brown (Fig. 15). Female cervical sclerite smooth, without swelling. Paired spermathecal duct stems smooth and heavily swollen in the middle, swelling about same width as paired spermatheca (Fig. 16). Paired spermathecae oval and smooth. Single spermatheca cylindrical and smooth, without spine-like processes........................................................................ Paragrallomyia caliensis n. sp. Colombia (female only)

12) Black spot anterior to ocellar plate strong and teardrop shaped (Fig. 47).................................................................................................... Paragrallomyia teresacristinae (Albuquerque) Brazil

- Black spot anterior to ocellar plate rounded and sometimes weak.............................................. 13

13) Epicephalon flat, about same level as fronto-orbital plate. Mesonotum with two rows of long black setae on postpronotal lobe margin (Fig. 29)............................................. Paragrallomyia inpai (Albuquerque) Brazil, Bolivia

- Epicephalon somewhat swollen, above level of fronto-orbital plate (Figs. 43). Margin of postpronotal lobe margin bare or with sparse and small dark microsetulae...................................................................... 14

14) Cervical sclerite with a brownish rounded swelling in both sexes. Four spermathecae (Fig. 44)........................................................................................... Paragrallomyia quaternaria n. sp. Bolivia

- Cervical sclerite smooth or with a small oval white swelling (female unknown for P. bifurcata). Known females with three spermathecae (Figs. 7, 11, 13).......................................................................... 15

15) Female cervical sclerite smooth, without swelling and covered by white pruinosity. Fronto-orbital plate yellowish-brown (Figs. 12, 14).............................................................. Paragrallomyia brasiliensis n. sp. Brazil

- Female cervical sclerite with a white opaque oval swelling. Fronto-orbital plate dark brown (Figs. 6, 8, 10)............. 16

16) Pleural membrane greyish with a white vertical stripe on P3 (Fig. 6, 8). Single spermatheca cylindrical with small finger-like processes (Fig. 7)......................... Paragrallomyia albibasis (Enderlein) Belize, Colombia, Costa Rica, Mexico

- Pleural membrane uniformly darkened (Fig. 10). Single spermatheca forked and smooth, with small rounded swellings (Fig. 11).................................................... Paragrallomyia bifurcata n. sp. Costa Rica (female only)