Gyrinus species

Key to the adult Gyrinus species of Venezuela

1 Dorsally black in color ( Figs 33–38 View Figs 29–33 View Figs 33–38 ), venter mostly dark – medially brown to black in color; elytron with punctures of all 11 serial striae distinguishable ( Figs 33–38 View Figs 29–33 View Figs 33–38 , 43, 45 View Figs 43–46 ); metanepisternal ostiole present. Subgenus Oreogyrinus . ................................. 2

– Dorsally olive green in color ( Figs 1–6 View Figs 1–6 ), venter lighter – yellow to orange in color; elytron with at least one (stria I) or more medial serial striae totally effaced or with strongly reduced punctures ( Figs 1–6 View Figs 1–6 , 18, 20 View Figs 18–21 , 25, 27 View Figs 25–28 ); metanepisternal ostiole absent. Subgenus Neogyrinus . .............................................................................................. 5

2 Pronotal transverse crease strongly impressed ( Figs 33–36 View Figs 29–33 View Figs 33–38 , 39–40 View Figs 39–40 ); pronotal and elytral lateral margins densely riffled ( Figs 39–42 View Figs 39–40 View Figs 41–42 ); dorsal surface not iridescent ( Figs 33–36 View Figs 29–33 View Figs 33–38 ); strongly sexually dimorphic, female elytra strongly reticulate laterally ( Figs 33 View Figs 29–33 , 35 View Figs 33–38 , 44, 46 View Figs 43–46 ). .......................................................................................................... 3

– Pronotal transverse crease greatly reduced ( Figs 37–38 View Figs 33–38 ); pronotal and elytral lateral margins without riffles; dorsal surface iridescent ( Figs 37–38 View Figs 33–38 ); not sexually dimorphic in elytral sculpturing. ......................... Gyrinus ( Oreogyrinus) iridinus sp. nov.

3 Pronotum relatively weakly wrinkled, laterally with sparserwrinkles ( Fig. 39 View Figs 39–40 ); elytral lateral margin weakly interrupted in apical 1/5 by swelling (as in Fig. 41 View Figs 41–42 ); aedeagus not strongly constricted in apical 1/3, more evenly attenuated towards apex, at most weakly constricted in apical 1/3. .............................................................................. 4

– Pronotum more strongly wrinkled, laterally often with many wrinkles ( Fig. 40 View Figs 39–40 ); elytral lateral margin strongly interrupted in apical 1/5 by large swelling ( Fig. 42 View Figs 41–42 ); aedeagus strongly constricted in apical 1/3 ( Fig. 49 View Figs 47–50 ); gonocoxae curved with truncate apices ( Fig. 59 View Figs 51–59 ). .................................... Gyrinus ( Oreogyrinus) vinolentus sp. nov.

4 Female elytron more reticulate, nearly entirely covered in reticulation or at least to elytral interval II; male aedeagus attenuated in basal 2/3, weakly expanded laterally in apical 1/3 ( Fig. 47 View Figs 47–50 ); gonocoxae not studied. Not confirmed to be in Venezuela. ................................................. Gyrinus ( Oreogyrinus) colombicus Régimbart, 1883

– Female elytron less reticulate, reticulation reaching at most to elytral interval IV; male aedeagus strongly parallel sided, apex broadly rounded ( Fig. 48 View Figs 47–50 ); gonocoxae relatively straight, not strongly curved, apices weakly emarginate with prominent lateral angle ( Fig. 58 View Figs 51–59 ). ........................................ Gyrinus ( Oreogyrinus) venezolensis Ochs, 1953

5 Body form broadly oval ( Figs 1–3, 5 View Figs 1–6 ); elytra with non-uniform reticulation, lateral reticulation distinctly more strongly impressed than medially. ............................... 6

– Body form narrowly oval ( Figs 4, 6 View Figs 1–6 ); elytra with more uniform reticulation, laterally not distinctly more strongly impressed. ................................................................... 8

6 Elytra with at least serial striae VIII–IX sulcate (as in Fig. 7 View Figs 7–11. 7–9 ); elytral apex obliquely truncate ( Figs 1 View Figs 1–6 , 8 View Figs 7–11. 7–9 ), at most with incomplete border present laterally; ultimate abdominal tergite without strong medial acumination. ................................................... 7

– Elytra with serial striae VIII–IX at most weakly sulcate ( Fig. 10 View Figs 7–11. 7–9 ); elytral apex rounded, with complete border ( Fig. 11 View Figs 7–11. 7–9 ); ultimate abdominal tergite often with strong medial acumination................................. Gyrinus ( Neogyrinus) gibbus Aubé, 1838

7 Elytral serial striae VIII–X never lineate, with distinctly separated round punctures ( Fig. 21 View Figs 18–21 ); epipleural angle of elytral apex always distinct, normally with denticle ( Fig. 9 View Figs 7–11. 7–9 ); aedeagus with median lobe shorter than parameres, apex with broad process ( Fig. 29 View Figs 29–33 ); gonocoxae short, with strongly truncate apices ( Fig. 53 View Figs 51–59 ). Very widespread Neotropical species................................. Gyrinus ( Neogyrinus) ovatus Aubé, 1838

– Elytral serial striae VIII–X lineate basally with ovoid punctures; epipleural angle of elytral apex always indistinct, never with denticle; aedeagus with median lobe as long as parameres, apex evenly rounded without broad process ( Fig. 30 View Figs 29–33 ); gonocoxae elongate, apices laterally weakly emarginate with prominent lateral angle ( Fig. 56 View Figs 51–59 ). Species known only from the Gran Sabana in southeastern Venezuela. ..................... ................................................................ Gyrinus ( Neogyrinus) sabanensis sp. nov.

8 Elytral serial striae II–XI evident ( Figs 24 View Figs 22–24. 22–23 , 27 View Figs 25–28 ), striae VI–IX sulcate with distinct round punctures ( Fig. 28 View Figs 25–28 ); elytra without distinct pre-apical medial plica; elytral apex obliquely truncate, with distinct epipleural angle ( Fig. 24 View Figs 22–24. 22–23 ); aedeagus with median lobe exceptionally long and broad, apex truncate ( Fig. 32 View Figs 29–33 ); gonocoxae shorter with strongly emarginate apices producing a strongly pointed medial angle ( Fig. 55 View Figs 51–59 ). ...... .................................................................... Gyrinus ( Neogyrinus) rozei Ochs, 1953

– Elytral serial striae VI–XI evident ( Fig. 22 View Figs 22–24. 22–23 ), striae VI–X sulcate with linear punctures ( Fig. 26 View Figs 25–28 ); elytra with distinct medial pre-apical plica ( Fig. 23 View Figs 22–24. 22–23 ); elytral apex rounded, without distinct epipleural angle ( Fig. 23 View Figs 22–24. 22–23 ); aedeagus shorter than parameres, narrow, apex strongly triangular in form ( Fig. 31 View Figs 29–33 ); gonocoxae more elongate with rounded apices ( Fig. 54 View Figs 51–59 ). .................................... Gyrinus ( Neogyrinus) guianus Ochs, 1935