Geniatini, Burmeister, 1844

Jameson, Mary Liz & Hawkins, Shauna Joy, 2005, Synopsis of the genera of Geniatini (Coleoptera: Scarabaeidae: Rutelinae with an annotated catalog of species), Zootaxa 874 (1), pp. 1-76 : 13-14

Key to the Genera of Geniatini

Males: Protarsomeres dorsoventrally flattened, densely setose ventrally ( Figs. 30–31, 33– 34 ); terminal sternite with margin emarginated; abdominal sternites in lateral view appearing concave or flat. Females: Protarsomeres dorsoventrally flattened or not, with or without dense ventral setae; terminal sternite with margin entire or rounded, not emarginated; abdominal sternites in lateral view appearing convex.

1. Mentum with apicomedial, tooth­like projection ( Fig. 16 , 41 ) .................................... 3

1’. Mentum without apicomedial, tooth­like projection ( Figs. 38–40 ) ............................. 2

2. Apex of mentum with medial notch, not crenulate ( Figs. 39–40 ). All claws simple on all legs ........................................................................................... Rhizogeniates Ohaus

2’. Apex of mentum crenulate ( Fig. 38 ). Modified claw moderately split on all legs ....... .................................................................................................. Mimogeniates Martínez

3. Mesosternum anterior to mesocoxae strongly concave ( Fig. 52 ) ................................... ................................................................................. Xenogeniates Villatoro & Jameson

3’. Mesosternum anterior to mesocoxae flat or slightly convex, not strongly concave ( Fig. 51 ) ............................................................................................................................... 4

4. Stipes of maxilla produced, with well­developed lateral lobe ( Fig. 43 ) or lateral angle ( Fig. 42 ) ......................................................................................... Lobogeniates Ohaus

4’. Stipes of maxilla not produced, instead rounded or broadly rounded ( Fig. 44 ) ........... 5

5. Mandible with rounded, recurved, apical lobe ( Fig. 20 ). Dorsal surface with abundant, decumbent, white setae. Antennal club of male twice length of segments 2–7; antennal club of female subequal to segments 2–7 ....................................... Eunanus Ohaus

5’. Mandible lacking rounded, recurved, apical tooth; instead simple (e.g., Fig. 19 ). Dorsal surface with or without sparse setae. Antennal club of male and female subequal to or slightly longer than segments 2–7 ....................................................................... 6

6. Length of antennal club half or less than half length of first antennal segment ( Figs. 5 , 23 ). Clypeal apex (in lateral view) sloped 45º with respect to dorsal plane of clypeus ( Figs. 23 , 36 ). Male tarsomeres simple, not flattened and dilated ( Fig. 32 ) .................. ................................................................................................ Geniatosoma Costa Lima

6’. Length of antennal club more than half length of first antennal segment. Clypeal apex (in lateral view) sloped 60–90º with respect to dorsal plane of clypeus ( Fig. 37 ). Male tarsomeres dorsoventrally flattened and dilated (e.g., Fig. 34 ) .................................... 7

7. Form of clypeus parabolic, apex not reflexed ( Fig. 24 ). Mandible exposed, apex narrowly rounded ( Fig. 24 ). Male with all claws appearing simple on all legs ................. ...................................................................................................... Heterogeniates Ohaus

7’. Form of clypeus not parabolic (instead rounded, quadrate), apex reflexed (e.g., Figs. 19–20, 22, 25–26 ). Mandible exposed or not, apex broadly rounded (e.g., Figs. 19, 23, 25 ). Male with claws obviously toothed on some or all legs ...................................... 8

8. Length of protarsomeres 2–4 subequal in length to protarsomere 5 ( Fig. 31 ). Clypeus of male with lateral margins expanded, apex quadrate ( Fig. 21 ); clypeus of female with lateral margins parallel, apex quadrate ............................................ Evanos Ohaus

8’. Length of protarsomeres 2–4 greater than length of protarsomere 5 ( Figs. 30, 33–34 ). Clypeus of male and female with lateral margins constricted, apex rounded or trapezoidal (e.g., Figs. 19, 22, 25–28 ) .................................................................................. 9

9. Elytral margin with deep, setose punctures on lateral edge from apex of metepisternum to apex of elytra ( Figs. 45a–b, 46a–b )......................................................................... 10

9’. Elytral margin without deep, setose punctures on lateral edge from apex of metepisternum to apex of elytra ................................................................................................. 11

10. Elytral margin with well­developed stridulatory ridge and with rigid stridulatory setae ( Fig. 45a–b ). Apex of metafemur (dorsal view) with stridulatory patch ( Fig. 35 ) ........ ........................................................................................................ Trizogeniates Ohaus

10’.Elytral margin lacking stridulatory ridge and without rigid stridulatory setae ( Fig. 46a– b ). Apex of metafemur (dorsal view) lacking stridulatory patch .......... Geniates Ohaus

11. Eyes small, interocular width greater than 6 transverse eye diameters (e.g., Fig. 19 ) 12

11’. Eyes larger, interocular width less than 5 transverse eye diameters (e.g., Fig. 25 ) ....... ..................................................................................................... Leucothyreus Macleay

12. Protarsomere 5 dorsoventrally flattened, width more than half length ( Fig. 30 ). Length of body from apex of clypeus to apex of elytra more than 9.0 mm ............................... .......................................................................................... Bolax Fischer von Waldheim

12’.Protarsomere 5 dorsoventrally flattened or not; if flattened, then width less than half length. Length of body from apex of clypeus to apex of elytra less than 9.0 mm ........ ................................................................................................... Microchilus Blanchard

Figures

FIGURES 30–35. Male forelegs (dorsal view) showing comparison of tibial apex, protarsomeres, and claws of: 30) Bolax magna, 31) Evanos villatus, 32) Geniatosoma lindemannae, 33) Microchilus lineatus, and 34) Trizogeniates temporalis. Hind leg (dorsal view) of: 35) Trizogeniates temporalis showing location of stridulatory file at the apex of the metafemur.

FIGURES 14–18. Head in lateral view showing major characters of: 14) homalochilous Rutelinae (labrum projecting anteriorly with respect to the clypeus; tribes Anomalini and Rutelini) and 15) orthochilous Rutelinae (labrum projecting ventrally with respect to the clypeus; tribes Geniatini, Anoplognathini, Adoretini, and Spodochlamyini). Head in frontal view showing characters of orthochilous Rutelinae of: 16) Geniatini and Anoplognathini with labrum and mentum (each) possessing median, apical tooth or projection, 17) Adoretini with labrum only possessing median, apical tooth or projection, 18) Spodochlamyini lacking median, apical tooth on either labrum or mentum.

FIGURES 36–44. Head and apex of thorax in lateral view showing: 36) Clypeal apex sloped 45º with respect to dorsal plane of clypeus in Geniatosoma lindemannae (male) and 37) Clypeal apex sloped 60–90º with respect to dorsal plane of clypeus in Trizogeniates tibialis. Mentum (ventral view) showing: 38) Mimogeniates margaridae (apex quadrate and crenulate, lacking apicomedial tooth), 39) Rhizogeniates antennatus (weakly emarginate apically, lacking apicomedial tooth), 40) Rhizogeniates carbonarius (weakly emarginate apically, lacking apicomedial tooth, 41) Trizogeniates foveicollis (apex with apicomedial tooth­like projection). Maxilla (ventral view) showing: 42) Lobogeniates borgmeieri (stipes produced, with lateral angle), 43) Lobogeniates catullus (stipes produced, with well­developed lateral lobe), 44) Trizogeniates foveicollis (not produced, instead rounded or broadly rounded).

FIGURES 51–52. Thorax in ventral view showing: 51) Mesosternum without invagination (Bolax magna) and 52) Mesosternum with invagination in black (Xenogeniates martinezi).

FIGURES 19–29. Head in dorsal view showing form of clypeus, mouthparts, and eye size in: 19) Bolax rutila, 20) Eunanus murinus, 21) Evanos villatus (male), 22) Geniates borellii, 23) Geniatosoma lindemannae, 24) Heterogeniates bonariensis (male), 25) Leucothyreus kirbyanus, 26) Trizogeniates tibialis. Head and pronotum in dorsal view showing form in: 27) Geniates borellii, male (head lacking tubercle, pronotum lacking concavity), 28) Geniates cornutus, male (head with tubercle, pronotum with concavity), 29) Geniatosoma lindemannae, male (head lacking tubercle, pronotum with concavity and weak, apical tubercle).

FIGURES 5–8. Habitus illustrations of: 5) Geniatosoma nigrum (male), 6) Heterogeniates bonariensis (male), 7) Leucothyreus kirbyanus (male), 8) Lobogeniates collaris (male).

FIGURES 45–50. Left elytral epipleuron showing: 45) dorsal view of stridulatory ridge in T. foveicollis (a) and ventral view of stridulatory ridge in T. foveicollis (b), 46) dorsal view of elytral epipleuron without stridulatory ridge in G. cylindricus (a) and ventral view of elytral epipleuron without stridulatory ridge in G. cylindricus (b). 47) Lateral view of Geniates sp. showing elytral margin with membranous border. Apex of male forelegs (lateral view) showing comparison of claws of: 48) Bolax flavolineata (both claws toothed), 49) Geniates borellii (inner claw with thumblike projection, outer claw simple), 50) Geniates flaviventris (inner claw toothed, outer claw simple).