Pseudogeniates Ohaus, 1910

Jameson, Mary Liz & Ocampo, Federico, 2012, Synopsis of the Argentinian scarab genus Pseudogeniates Ohaus (Coleoptera, Scarabaeidae, Rutelinae), ZooKeys 241, pp. 33-53 : 37-39

Pseudogeniates Ohaus, 1910 Figs 1-22

Pseudogeniates Ohaus 1910: 179-180

Type species.

Pseudogeniates richterianus Ohaus 1910: 180. By monotypy.

Tribal classification.

The genus Pseudogeniates is a member of the tribe Rutelini . In overall appearance, however, species in the genus Pseudogeniates are similar to species in the genera Geniates ( Geniatini ) and Anomala ( Anomalini ). Species in the genus Pseudogeniates can be separated from both of these tribes based on the margin of the elytra that lacks an obvious membranous border (membranous border present at the elytral apex in both Geniatini and Anomalini ). Additional characters that separate the Rutelini and Geniatini include: the labrum that is horizontally produced with respect to the clypeus in the Rutelini (vertically produced in the Geniatini ) and protarsomeres that are subcylindrical and lacking ventral setose pads (dorsoventrally flattened and densely setose ventrally in the Geniatini ). Additional characters that separate the Rutelini and Anomalini include: protibia with inner, protibial spur apical in the Rutelini (inner, apical spur subapical in Anomalini ) and terminal spiracle positioned in pleural suture in the Rutelini (terminal spiracle not positioned in pleural suture in Anomalini ). For a key to tribes of Rutelinae , see Jameson (1990, 2005).

Subtribal classification.

Ohaus (1915, 1934) placed the genus Pseudogeniates in the tribe Rutelini and subtribe Pelidnotina . Based on morphological data, this subtribe was demonstratively paraphyletic and it was eliminated ( Jameson 1998). Soula (2009), without justification or discussion, continued use of this higher-level taxon for the genus. We consider the genus Pseudogeniates to be a member of the tribe Rutelini (without subtribal designation).

Phylogeny.

Sister group relationships have not been examined for the genus or for species within the genus.

Diagnosis of adults.

Members of the genus Pseudogeniates differ from other genera in the tribe Rutelini by the following combination of characters: feathery fringe of setae on the ventral edge of the elytra present; elytra obviously striate (Figs 1-3); mesosternal peg lacking; claws simple on all legs (not toothed) (Figs 11-13); frontoclypeal suture incomplete (Figs 16-18); clypeal apex broadly reflexed (Figs 16-18); apex of labrum extending beyond clypeal apex, visible from dorsal view (Fig. 18); apex of mandible with one, apical, recurved tooth (Figs 4, 18); maxillary teeth lacking (Fig. 5).

Similar taxa.

Species in the genus Pseudogeniates share several characters with Parhomonyx fuscoaeneus Ohaus, a monotypic taxon that is also endemic to southern South America. The following characters are shared: fringe of setae at apex of elytra, mesosternal process lacking, mandible with one external tooth, elytra striate, and claws simple. However, Pseudogeniates differs from Parhomonyx based on the external margin of the mandible that is straight (external margin lobe-like in Parhomonyx ), maxillary teeth lacking (maxilla with well developed teeth in Parhomonyx ), maxillary palp rod-shaped (broadly elliptical in Parhomonyx ), and fifth tarsomere on all legs of males and females lacking an internal tooth (with two well developed internal teeth on the fifth meso- and metatarsomeres of males and females of Parhomonyx ).

Description of adults.

Length from apex of clypeus to apex of pygidium 12.0-19.0 mm; width at mid-elytra 6.0-11.0 mm. Color: Dorsal and ventral surfaces testaceous to castaneous. Form (Figs 1-3): Elongate oval, sides subparallel, pygidium exposed beyond apices of elytra, apex of elytra broadly rounded. Head (Figs 16-18): Disc of frons and clypeus in lateral view nearly flat, clypeus with margins and apex reflexed. Frons and clypeus variably sculptured, punctate and/or rugose. Frontoclypeal suture weakly indicated, incomplete at middle. Eye canthus weakly cariniform. Interocular width 2.9-4.8 transverse eye diameters. Clypeal apex rounded or quadrate, with or without basolateral constriction, lacking bead; frontal view flat, length (at middle) about 1/3 length of frons, disc variably punctate and setose. Mandible (Fig. 4) with 1 apical, acute, recurved tooth; scissorial region with 1 poorly developed tooth; molar region narrow. Labrum projecting beyond clypeus, trapezoidal, apex emarginate or quadrate; apex moderately emarginate medially, surface moderately densely punctate, punctures moderate in size, some setose (setae moderately long and short, rufous). Maxilla (Fig. 5) lacking teeth; galea fused or not, with moderately dense, moderately long setae and with 1 to 2 long, bristle-like seta on disc; terminal segment of palpus with dorsal, longitudinal sulcus from based to sub-apex. Mentum (Figs 8-10) rectangular, trapezoidal, or pentagonal, inner apex produced anteriorly or not, with or without inner shelf. Antenna 9 or 10-segmented with 3-segmented club; club subequal in length to segments 1-7 combined or slightly longer than segments 1-7 combined. Pronotum: Widest at middle, apical angles obtuse, basal angles obtuse. Dorsal surface punctate, rugopunctate, or imbricate, with or without median line. Bead complete anteriorly, laterally, and basally. Margin sparsely setose (setae short, rufous). Scutellum: Parabolic, wider than long; base declivous at elytral base. Wing: Dense, thick setae present anterior to RA3+4 to apex; ScA with dense, thick setae near fold, lacking precostal pegs; AA1+2 shorter than AA3+4 (Fig. 7). Mesepimeron: Apex entirely hidden by base of elytra in dorsal and lateral views. Elytra: Variably sculptured with longitudinal, punctate striae; punctures variable. Sutural stria sulcate, impressed from base of scutellum to apex. Epipleuron from base to mid-metacoxa with shelf and associated setae; epipleuron from mid-metacoxa to apex beaded and with associated setae. Apex of elytra weakly rounded; sutural apex spiniform, rounded, or square. Elytral sutural length about 6.5 times length of scutellum. Propygidium: Hidden beneath elytra. Pygidium: Semitriangular, about twice as wide as long at middle; variably sculptured, punctate, shagreened, or weakly rugose. Margins beaded. Apex rounded. Apical bead with moderately long to long setae; setae tawny to rufous or testaceous. Venter: Prosternal keel triangular; apex projecting anteroventrally at about 35° with respect to ventral plane; apex produced to level of protrochanter, blunt; surface flat (lacking protuberance). Mesometasternal keel lacking. Sternites 1-4 subequal in length in male and female, sternites 5-6 about twice length of sternite 4. In lateral view, male sternites flat, female sternites weakly convex. Last sternite with apex quadrate in male, posteriorly rounded in female. Legs: Protibia (male and female) with width at base 1/3rd to 1/4th greater than width at apex (Figs 11-13), inner base with weak Protibial notch, with 3 external teeth in apical half (2 apical teeth removed from basal tooth external teeth or not); spur present, subapical. Modified foreclaw of male (Fig. 11) about 3 times width of unmodified claw, not toothed, inner apical tooth present at apex, small. Foreclaws of female simple, internal claw slightly wider than outer claw. Unguitractor plate laterally flattened, exposed beyond tarsomere 5; apex with 0-1 moderately long setae. Mesotibia with sides subparallel, apex weakly divergent; external edge with 2 carinae; inner apex with 2 spurs; apex with 10-20 spinulae. Meso- and metatarsomere 4 apicomedially with 4 medial spinulae (male) or 2 medial spinulae and 1 seta-like long spinule laterad of each medial spinula (female). Meso- and metatarsal claws of male and female simple, internal claw slightly wider than outer claw. Metarsomere 1 moderately divergent at middle and apex (male and female). Metatrochanter with apex weakly produced beyond posterior border of femur. Metacoxal corner (female) rounded or square. Metatibia (Figs 14-15) with sides subparallel, divergent towards apex; external edge with 1-2 carinae; inner apex with 2 spurs; inner apex with 25-40 short, stout spinulae. Spiculum gastrale: Y-shaped, lacking associated sclerites (Fig. 6). Parameres and phallobase: Plates fused dorsally/ventrally (not laterally). Dorsal plate symmetrical, apex rounded and with or without two apical, rounded teeth (Figs 19-21); not diagnostic for species. Ventral plate elongate (as long as dorsal plate or ½ length of dorsal plate), apex acute, quadrate, or rounded; diagnostic, species specific (Figs 19-21). Parameres slightly longer than phallobase. Female Genitalia: Gonocoxites subquadrate with sparse setae; not diagnostic for species.

Composition and distribution.

The genus Pseudogeniates is composed of three species that are distributed entirely in Argentina (Fig. 22). Species are associated with arid areas of the Pampa, Espinal, Chaco, and Monte eco-regions in Argentina .

Biology.

Very little is known of the biology of the species in the genus. Males and females are attracted to lights at night. Based on the extreme wear on the protibia of some specimens, individuals probably are associated with soil and use their front appendages for digging.

Etymology.

The name Pseudogeniates ("the false Geniates ") refers to the similarity in form to some species in the ruteline genus Geniates .

Key to species of Pseudogeniates

(Males: Protarsus with inner claw enlarged [Fig. 11]; abdomen ventrally flat or concave. Females: Protarsus with inner claw not enlarged, similar in size to outer claw [Figs 12-13]; abdomen ventrally swollen or weakly convex.)