Sclerogibbidae, Ashmead, 1902

Olmi, Massimo, Marletta, Alessandro, Guglielmino, Adalgisa & Speranza, Stefano, 2016, Protosclerogibba australis gen. et sp. nov., new genus and species of sclerogibbid wasps (Hymenoptera: Sclerogibbidae) from South Africa, Zootaxa 4085 (1), pp. 127-134 : 131-132

Key to genera of world Sclerogibbidae

Females

1. Macropterous (fossil species) ( Fig. 14 ; fig. 1 in Engel & Grimaldi 2006).............................................................................................. Pterosclerogibba Olmi and Sclerogibbodes Engel & Grimaldi

- Apterous or micropterous (extant and fossil species) ( Figs 4–8 , 13 ).............................................. 2

2. Micropterous ( Figs 1, 2 , 4, 5 ); frons not produced over base of antennae (antennal toruli not concealed in dorsal view) ( Figs 2 , 4, 5 ); palpal formula 6/4.......................................................... Protosclerogibba gen. nov.

- Apterous ( Figs 6–9 ); frons produced over base of antennae (antennal toruli concealed in dorsal view) ( Fig. 9 ); palpal formula from 2/1 to 6/3, never 6/4............................................................................... 3

3. Mesosoma crossed by a straight suture separating the metanotum and scutellum from the propodeum and distinctly crossing the body ( Fig. 6 ); metanotum composed of two very large pieces situated on the sides of the scutellum ( Fig. 6 ); head usually with 2 ocelli ( Fig. 6 ), rarely with 3 ocelli; eyes usually small, approximately situated half-way in the head lateral margin ( Fig. 6 ); occasionally eyes larger and situated in the posterior third of the head; anterior flat surface of hypostomal bridge as long as first antennal segment, or slightly shorter; tibial spurs 1/1/2............................. Caenosclerogibba Yasumatsu

- Mesosoma never crossed by a straight suture separating the metanotum and scutellum from the propodeum ( Figs 7, 8 ); metanotum usually composed of two narrow pieces situated on the sides of the scutellum ( Figs 7, 8 ); occasionally the above pieces are large, but in this case the suture separating the metanotum and scutellum from the propodeum is always curved; head with 3 ocelli ( Figs 7, 8 ); eyes always large, situated in the posterior two thirds of the head ( Figs 7, 8 )...................... 4

4. Tibial spurs formula 1/1/2; anterior flat surface of hypostomal bridge as long as first antennal segment, or slightly shorter ( Figs 10, 11 )............................................................................. Probethylus Ashmead

- Tibial spurs formula 1/2/2; first antennal segment at least twice as long as anterior flat surface of hypostomal bridge ( Fig. 12 )...................................................................... Sclerogibba Riggio & De Stefani-Perez

Figures

FIGURES 13, 14. Fossil females in amber of Probethylus poinari Olmi (13) and Pterosclerogibba antiqua Olmi (14). Scale bar 0.49 mm (13), 0.57 mm (14).

FIGURES 4 – 5. Protosclerogibba australis sp. nov., holotype, ♀. 4, dorsal view; 5, lateral view (metasoma in unnatural horizontal position for better gluing it to the label; natural position is oblique and vertical as in figure 2). Scale bar 1.94 mm (4), 1.80 mm (5).

FIGURES 6 – 8. Females of Sclerogibbidae. 6, Caenosclerogibba longiceps (Richards); 7, Probethylus callani Richards; 8, Sclerogibba magrettii (Kieffer). Scale bar 0.69 mm (6), 1.36 mm (7), 1.52 mm (8).

FIGURES 1 – 3. Protosclerogibba australis sp. nov., holotype, ♀. 1, dorsal view; 2, lateral view; 3, head in ventral view (a: first antennal segment; h: hypostomal bridge). Seventh exposed segment of gaster very small. Scale bar 1.89 mm (1), 1.87 mm (2), 0.93 mm (3).

FIGURES 9 – 12. 9. Probethylus callani Richards, ♀, lateral view. 10 – 12, head in ventral view of females of Probethylus callani Richards (10), Probethylus schwarzi Ashmead (11) and Sclerogibba embiopterae Dodd (12). a: first antennal segment; h: hypostomal bridge. Scale bar 1.05 mm (9), 0.13 mm (10), 0.92 mm (11), 0.20 mm (12).