Pseudogeniates richterianus Ohaus, 1910

Jameson, Mary Liz & Ocampo, Federico, 2012, Synopsis of the Argentinian scarab genus Pseudogeniates Ohaus (Coleoptera, Scarabaeidae, Rutelinae), ZooKeys 241, pp. 33-53 : 44-46

Pseudogeniates richterianus Ohaus, 1910 Figs 3-4, 7, 10, 12-13, 15, 18, 21-22

Pseudogeniates richterianus Ohaus 1910: 180.

Pseudogeniates richteri Ohaus (lapsus in Ohaus 1934, table 2, figure 6).

Material examined.

Two female co-types examined at ZMHB. Female lectotype labeled: a) "ARGENTINA Buenos Aires XII.08 H.R." (typeset and handwritten on upperside and underside of white label), b) "Pseudogeniates Richteri cotype Ohs." ( Ohaus’ handwritten, red label), c) "SYNTYPUS Pseudogeniates richterianus Ohaus, 1910 labelled by MNHUB 2007" (typeset, red label), d) "Lectotype 2009 Pseudogeniates Richterianus Oh. Soula" (typeset and handwritten, red label). Paralectotype female labeled: a) "Rep. Argentina Prov. Santa Fe, R. Richter", b) female symbol, c) mouthparts card-mounted, d) “Typus!” (typeset, red label), e) "Pseudogeniates Richterianus Oh." ( Ohaus’ handwritten, red label), f) "SYNTYPUS Pseudogeniates richterianus Ohaus, 1910 labelled by MNHUB 2007" (typeset, red label), d) "Lectotype 2009 Pseudogeniates Richterianus Oh. Soula det." (typeset and handwritten, red label). The paralectotype has the head, thorax, and abdomen glued together. It is, in fact, a chimera with the head of Parhomonyx fuscoaneus and body of Pseudogeniates richterianus . Ohaus (1910) stated that he described the species based on three female specimens from Santa Fé, Argentina (Hans Richter collection) and Buenos Aires. The location of one specimen is not known.

Description

(based on 4 males and 22 females). Length 12.0-18.4 mm. Widest width 7.8-10.0 mm. Color: Dorsum, venter, and appendages rufotestaceous to castaneous (Fig. 3). Head (Fig. 18): Frons moderately densely punctate or rugopunctate; punctures small and moderately large, mixed. Clypeus with dorsal surface weakly rugopunctate, punctures small and large, mixed; shape broadly rounded apically and laterally or subquadrate, with or without constriction basolaterally, apex and sides broadly reflexed; disc (frontal view) moderately densely punctate or rugopunctate, punctures small and large, mixed, some setose (setae short, testaceous, sparse). Labrum with setae moderately long and short, testaceous. Maxilla with galea not fused, with 1-2 moderately long, bristle-like medial setae. Mentum (Fig. 10) longer than wide, rectangular, inner apex projecting anteriorly, without inner shelf. Antenna 9 or 10-segmented with 3-segmented club; club subequal to or slightly longer than stem. Pronotum: Medial line weakly impressed or obsolete. Surface (disc) moderately densely punctate (mid-disc), rugopunctate, or imbricate; punctures small to moderate. Margin with setae moderately long, testaceous. Elytra: Elytral apex rounded, quadrate, or with obtuse angle. Discal stiae, sulcate-punctate; 5 on disc mesad of humerus, 5 laterad of humerus; discal stria 1 (adjacent to sutural stria) extending from base to apex, stiae 2-6 extending from near base to apical umbone; humeral stria 1 incomplete (extending from mid-elytron to near apical umbone), stria 2 extending from humerus to near apical umbone, striae 3-4 extending from base of metacoxa to near apical umbone (indicated by punctures, not sulcate), stria 5 extending from base of metacoxa to subapex (indicated by punctures near base, sulcate near apex); punctures small to moderate in size, some longitudinal. Intervals with moderately dense, random punctures, some transversely wrinkled (on disc), punctures small to moderate in size; interval 1 subequal in width to other intervals. Pygidium: Disc and apex moderately densely punctate or transversely rugopunctate; base and sides closely, rugopunctate or weakly rugose; punctures small. Legs: Protarsomere 5 of male slightly longer than tarsomeres 2-4. Modified foreclaw of male slightly longer than tarsomeres 2-4; internoapical tooth present. Protibia with external teeth often worn; 2 apical teeth removed from basal tooth; basal 1/3 weakly dilated (male; Fig. 12) or moderately dilated (female; Fig. 13). Mesotibia with sides subparallel, apex weakly divergent and weakly oblique; external edge with weak carina in basal 1/3, 1 carina in apical 1/3; apex with 8-14 short spinulae. Metatrochanter weakly produced beyond posterior border of femur. Metacoxal corner (female) rounded, with or without inner tooth. Metacoxa at middle not produced posteriorly. Metatibia (male) with sides subparallel, apex moderately divergent in apical 1/3; external edge with 1 carina in basal 1/4, 1 carina in apical 1/4; apex without corbel, with 2 inner spurs (spurs equal in width in male), inner apex with 28-35 short, stout spinulae. Metatibia (female; Fig. 15) greatly divergent at apical 1/4; external edge with 1 carina in basal 1/3, 1 carina in apical 1/3; apex without corbel, with 2 inner spurs, inner apex with 28-35 short, stout spinulae. Parameres: Ventral plate half length of dorsal plate (Fig. 21).

Diagnosis.

Pseudogeniates richterianus is a highly variable species. Variation is observed in the antenna (9- or 10-segmented), labrum (weakly or moderately emarginated), length of antennal club (subequal to slightly longer then the stem), elytral apex (spiniform, quadrate, rounded, or obtusely angled), pronotal medial line (weak or obsolete), and form of the clypeus. However, several characters reliably separate this species from others in the genus. Pseudogeniates richterianus is separated from Pseudogeniates intermedius and Pseudogeniates cordobaensis by the form of the mentum (rectangular and without inner shelf in Pseudogeniates richterianus [Fig. 10]; subtrapezoidal and with inner shelf in Pseudogeniates intermedius [Fig. 9]; pentagonal and nearly as wide as long in Pseudogeniates cordobaensis [Fig. 8]), ventral plate of the parameres (half length of the dorsal plate in Pseudogeniates richterianus [Fig. 21]; nearly as long as dorsal plate in Pseudogeniates intermedius and Pseudogeniates cordobaensis [Figs 20 and 19, respectively]), metacoxal corner in female (rounded in Pseudogeniates richterianus ; square in Pseudogeniates intermedius and in Pseudogeniates cordobaensis ), and posterior margin of the metacoxa (not produced posteriorly in Pseudogeniates richterianus ; produced posteriorly in Pseudogeniates intermedius and Pseudogeniates cordobaensis ).

Distribution

(Fig. 22). Pseudogeniates richterianus is the most wide-spread species in the genus. It is distributed in the Pampa, Espinal, and Monte de Llanuras y Mesetas (Monte) eco-regions in Argentina.

Locality data.

26 specimens deposited in CMNC, FMNH, IAZA, MACN, MLJC, UCCC, and ZMHB. ARGENTINA (26): BUENOS AIRES (16): Caballito, Dept. Puán, No data. MENDOZA (7): Lavalle (Brazo S. Río San Juan Area San Miguel 32°20'7"S, 68°26'57.9"W, 500 m), San Rafael, No data. NEUQUEN (1): No data. RIO NEGRO (1): Villa Regina. SAN JUAN (1): Los Berros (Dept. Sarmiento). SANTA FE (1): Rosario.

Temporal data.

November (5), January (3), February (1).

Natural history.

Based on specimens in collections, there is a female sex bias in this species (24 females: 4 males). Many specimens (male and female) have worn protibiae (Fig. 13), indicating that adults dig in abrasive soil. Label data indicate that this species was collected at mercury vapor light and at 500 m elevation.

Remarks.

Ohaus (1914) distinguished Pseudogeniates richterianus from Pseudogeniates intermedius based characters that vary within the species (see “Remarks” for P. intermedius), including number of antennal segments, form of the clypeus, and coloration. Although these characters are unreliable for diagnosis of the species, we provide characters that are useful (see “Diagnosis”). Ohaus (1910) named the species in honor of Herr Hans Richter from Buenos Aires.