Key to males of Neotropical species of the genus Atrichobrunettia .

1. Scape 3.0x the length of the pedicel; parameres stout, plate-like 2.0x the width of the base of gonostylus, with apical margin straight; post-hypandrial plate narrow ......................................................................... 2

– Scape 1.0x–2.0x the length of the pedicel; parameres triangular or, if plate-like, 1.0x–1.3x the width of the base of gonostylus, and with apical margin dentate; post-hypandrial plate very wide except in Atrichobrunettia bistria Quate and Atrichobrunettia spinata Bravo where it is narrow ............................................. 3

2. Aedeagal apodeme ending behind gonocoxal bridge ........................................................ A. pennata Bravo

– Aedeagal apodeme ending before gonocoxal bridge........................................................... A. bora (Bravo)

3. Eye bridge contiguous, wide, 1/ 3x the length of the head; R5 ending after the apex of the wing; gonocoxal apodemes not fused; post-hypandrial plate with apical alveoli; new subgenus Pachybrunettia ................ 4

– Eye bridge separated, narrow 1/ 4x – 1/ 5x the length of the head; R5 ending at apex of the wing; gonocoxal apodemes fused forming a gonocoxal bridge; post-hypandrial plate without alveoli; subgenus Polibrunettia Bravo ..................................................................................................................................................... 6

4. Radial fork apical to medial fork; the distance AB between the hypandrium and the gonocoxal apodeme is 1.5x – 2.0x the length of the paramere ........................................................................................................ 5

– Medial fork apical to radial fork; the distance AB between the hypandrium and the gonocoxal apodeme is 0.5x –0.7x the length of the paramere the length of the paramere .......................... A. triangularis sp. nov.

5. Apex of sternite 10 with two lateral lobes; foramen of epandrium small ..................... A. trilobata sp. nov.

– Apex of sternite 10 without lateral lobes; foramen of epandrium large ............................. A. minuta Bravo

6. Parameres rectangular, or sub-rectangular with internal lobe digitiform and acute at apex ....................... 7

– Parameres triangular ................................................................................................................................. 11

7. Paramere rectangular with denticulate apical margin; apex of aedeagus ending in forceps-like structure with shafts of aedeagus separated and curved inward to meet on the midline .................... A. bistria Quate

– Parameres sub-rectangular with internal lobe digitiform and acute apex; aedeagus shafts parallel; ampla group ........................................................................................................................................................... 8

8. Aedeagal apodeme narrow, as wide as gonocoxite; lateral margins of aedeagal apodeme parallel, and basal margin rounded ................................................................................................. A. amazonensis Bravo

– Aedeagal apodeme trapezoidal with apical margin smaller than basal margin; its greatest width is wider than the gonocoxite ..................................................................................................................................... 9

9. Aedeagal apodeme ending well behind the posterior margin of the gonocoxal bridge ....... A. ampla Bravo

– Aedeagal apodeme ending at or slightly behind the posterior margin of the gonocoxal bridge .............. 10

10. Aedeagal apodeme ending at the same level, or slightly before, the posterior margin of the gonocoxal bridge; medial fork apical to the radial fork ............................................................... A. paranaensis Bravo

– Aedeagal apodeme slightly behind the gonocoxal apodeme; radial fork apical to the medial fork ............. ............................................................................................................................................ A. spinata Bravo

11. Parameres larger than the aedeagal shafts; aedeagal apodeme narrow, filiform; longipenis group ......... 12

– Parameres smaller than the aedeagal shafts; aedeagal apodeme wide, having the same or greater width than the widest part of the gonocoxite; bispinata group............................................................................ 13

12. Parameres with parallel arms; posterior margin of post-hypandrial plate with inverted U-shape invagina- tion; aedeagus ending before posterior margin of the post-hypandrial plate .................... A. angelae Bravo

– Parameres with divergent arms; posterior margin of the post-hypandrial plate straight; aedeagus ending after the posterior margin of the post-hypandrial plate ................................................. A. longipenis Bravo

13. Aedeagal apodeme short, ending at the same level as the posterior margin of the gonocoxal bridge; post- hypandrial plate partially covering aedeagus shaft ...................................................... A. brevicornis Bravo

– Aedeagal apodeme long, ending behind posterior margin of the gonocoxal bridge; post-hypandrial plate ending where the aedeagus shaft begins, and therefore not covered by it ...................... A. bispinata Bravo