Tomarus Erichson 1847
Creators: name: López-García, Margarita M.
name: Deloya, Cuauhtémoc
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Dynastidae
Tomarus

description: Genus Tomarus Erichson, 1847
Tomarus Erichson, 1847: 95.
Type species: Tomarus maimon Erichson, 1847: 96 by monotypy.
Grylius Casey, 1915: 189 (as subgenus).
Type species: Ligyrus laevicollis Bates, 1888: 316 here designated.
Description. Length 17.7–30.0 mm. Humeral width 8.5–16.4 mm. Head: Clypeus subtriangular (Fig. 1H–K). Apical clypeal teeth triangular, slightly to widely separated. Ocular canthus rounded; without ventral or dorsal setae. Frons with 2 transverse to conical tubercles. Mentum subtriangular to subrectangular (Fig. 2I–K), with a strong constriction before apex; surface strongly concave at base. Mentum and ligula fused. Ligula well developed; covered with long, dense setae along lateral margins; ligular lobes fused or separated by a narrow emargination. Maxillary apical palpomere 1.3 times longer than the second palpomere. Maxilla with galea subquadrate (1.5 times longer than wide) (Fig. 4F–I); with 6 well-developed teeth (rarely reduced); maxillary teeth 3 and 4 in parallel position. Mandible with 2 apical teeth and a lateral, narrowly rounded tooth (Fig. 5F–H) or lateral tooth not well developed (Fig. 1J); incisor subequal (Fig. 5F) or longer than tooth 2 (Figs. 1J, 5H). Labrum subrectangular (Fig. 6D–G); apex straight; with long, dense setae. Antenna with 10 antennomeres, club short (1.3 times longer than antennomeres 2–7). Pronotum: Apical marginal bead complete. Apex with or without tubercle; without fovea or with deep, wide fovea. Scutellum: Surface with minute sparse punctures or with deep punctures forming a line parallel to lateral margins. Elytra: Inner surface of apex with rounded small to large tubercles forming 14–30 parallel lines (rarely not forming defined lines) (Fig. 8K–N). Wings: RA with sparse, small to minute peg-like setae on medial ventral region (Fig. 7F–H); without peg-like setae on dorsal surface. Edge of RA 3 with dense setae. Abdomen: Apex of tergite IV with a triangular wide area with tubercles forming diagonal parallel lines (Fig. 8G–J). Sternite VIII emarginate in male; entire in female. Pygidium with rugosity (Fig. 9F–L), slightly convex in male, nearly flat in female. Propygidium without stridulatory area. Venter: Prosternum wide, regularly rounded. Propleura with short, sparse setae on anterior region, medial region glabrous, posterior region with 5–10 sparse setae. Apex of prosternal process flat; without dorsal setae. Metepisternum with complete carina; inner surface with deep, large punctures, without setae; outer surface homogeneously rugose, without setae. Metasternum with large, deep, confluent punctures; with minute to short, sparse setae. Legs: Male protarsus simple, inner claw simple. Protibia tridentate, sometimes with an additional, basal denticle, teeth equidistant. Apical margin of meso- and metatibia entire to slightly crenulate. Metafemur without well-defined anterior row of punctures. Female genitalia: Subcoxite as long as wide. Coxite subrectangular (longer than wide); surface slightly concave. Subcoxite as wide as and shorter than coxite. Male genitalia: Phallobase 1.0–1.2 times longer than parameres. Parameres with 1–2 dorsal teeth, without ventral teeth. Internal sac with copulatory lamella and short to long lamellar spiny belt; with a complex of 3–8 (26 in T. pullus) spine-like accessory lamellae, with or without granules at base (Figs. 22–23).
Diagnosis. Tomarus can be differentiated from other Pentodontini genera by the following: Subtriangular clypeus, clypeal teeth triangular to transverse; frontoclypeus with 2 tubercles; antennal club short; pronotum usually with tubercle and with or without fovea; protibia tridentate (sometimes with a basal denticle) (Fig. 11H–J).; protarsus of male simple, inner claw simple; metafemur without well-defined anterior row of punctures; pygidium of male with transverse thin rugosity at base (Fig. 9F–L); prosternal process flat, without dorsal setae; internal sac with a complex of spine-like, accessory lamellae (Figs. 22–23); stridulatory apparatus consisting of a triangular wide area with tubercles forming 13–20 oblique, parallel lines on apex of sternite IV (Fig. 8G–J), and apical internal surface of elytra with rounded small to large tubercles forming 14–30 parallel lines (rarely not forming defined lines) (Fig. 8K–N).
Composition. 18 species.
Distribution. It is a Neotropical group probably originated in South America and dispersed along Central America, with few species reaching the tropical regions of Mexico, the Caribbean islands, and southern Florida in the United States of America.
Phylogenetic relationships. The morphological phylogeny of Tomarus (sensu lato) evidenced that this group, as previously considered, was polyphyletic and contained four different genera.
Taxonomic remarks. Erichson (1847) described the genus Tomarus to place a new species from Peru (T. maimon), characterized by having a maxilla with 6 teeth, elytra with stridulatory area, and mentum “ oblongus ”. A year later (Erichson 1848) he described T. gyas from Guiana. Lacordaire (1855) synonymized Tomarus with Ligyrus, and the synonymy was maintained for several years. Endrödi (1969) recognized Tomarus as a subgenus of Ligyrus. In more recent years, Ratcliffe (2003) revalidated the name Tomarus based on the priority principle, which was widely accepted. Although Escalona & Joly (2006) suggested maintaining the name Ligyrus due to the wide use and agricultural importance, they never submitted an application to the International Commission on Zoological Nomenclature. Morón & Grossi (2015) separated the genus into Ligyrus and Tomarus based on the number of teeth on the outer margin of mandible. Tomarus (sensu Morón & Grossi 2015) coincides only in part with the classification purposed in the present work. The species E. ebenus and E. similis are excluded, while T. adoceteus and T. pullus are included in Tomarus, and the species T. colombianus and T. rostratus (not considered in Morón & Grossi 2015) are also in Tomarus as well as other species described later: T. roigjunenti, T. laticaudus, T. maracaiboensis, and T. pilcopataensis.
Key to the species of the genus Tomarus
1 Pronotum without tubercle (Fig. 1J). Clypeus short (3.2 times wider than long). Mandible with incisor longer than second tooth, lateral tooth not well developed. Mentum subtriangular. Galea of maxilla with all teeth vestigial, teeth 3 and 5 absent. Internal sac with 26 spine-like accessory lamellae; lamellar spiny belt very long (Fig. 22A). Parameres as in Figs. 16M, 20D. Venezuelan and Colombian Orinoquia.................................................... Tomarus pullus (Prell, 1934)
- Pronotum with tubercle, which can be inconspicuous and only visible in lateral view. Clypeus longer (2.3–2.6 times wider than long). Mandible with incisor and second tooth subequal in length, lateral tooth slightly rounded to acute. Mentum abruptly constricted at apical 3rd. Galea of maxilla usually with well-developed teeth (teeth 5 and 6 vestigial in T. adoceteus and T. subtropicus), teeth 3 and 5 present. Internal sac with 3–8 spine-like accessory lamellae; lamellar spiny belt very short to short. ................................................................................................... 2
2 Pronotum without rugose fovea, with small to large punctures on each side of tubercle. Parameres strongly elongate, without lateral teeth (Fig. 16P). Spiculum gastrale with basal plates (Fig. 14F). Sternite VIII of female emarginate. Coastal desert of Peru and Chile ............................................................. Tomarus rostratus Dupuis, 2014
- Pronotum with rugose surface behind tubercle or pronotal fovea. Parameres with lateral teeth. Spiculum gastrale without basal plates. Sternite VIII of female rounded to slightly sinuate at apex............................................... 3
3 Pronotum with prominent tubercle, usually recurved. Pronotal fovea usually deep and large (Fig. 27C, E–F)............. 4
- Pronotum with small, rounded tubercle. Pronotal fovea shallow, as a rugose area behind tubercle or slightly deeper (Fig. 27 G–I)................................................................................................ 8
4 Metasternum with minute setae on anterior corners........................................................... 5
- Metasternum with short to long setae on anterior corners...................................................... 6
5 Pronotal fovea transversely oval and as wide as interocular distance. Parameres with the apical 8th triangularly dilated (Fig. 16C). Bolivia to Mexico ...................................... Tomarus bituberculatus (Palisot de Beauvois, 1811)
- Pronotal fovea narrower and shallow, sometimes as a rugose surface. Parameres with the apical 3rd triangularly dilated (Fig. 16Q). Pacific Coast of Mexico ............................................ Tomarus selanderi (Cartwright, 1959)
6 Pronotal fovea not completely rounded, slightly transverse. Metatibia not strongly widened towards apex. Apex of metatibia with 15–19 spinules. Parameres with very short to nearly absent lateral teeth, with the apical 4th roundly dilated (Fig. 16I). Ecuador, Peru, Chile, Guianas, and Brazil ....................................... Tomarus maimon Erichson, 1847
- Pronotal fovea rounded. Metatibia subtriangular, widened towards apex. Apex of metatibia with 21–30 spinules. Parameres with lateral teeth very long.............................................................................. 7
7 Apex of parameres narrow, ending in a triangular or rounded tip (Fig. 16F). Argentina to Costa Rica ................................................................................................ Tomarus gyas Erichson, 1848
- Apex of parameres thick (Fig. 16E). Venezuela to Mexico ................. Tomarus discrepans (Escalona & Joly, 2006)
8 Metasternum with minute setae on anterior corners. Internal sac with 7–8 spine-like accessory lamellae................. 9
- Metasternum with short to long setae on anterior corners. Internal sac with 3 spine-like accessory lamellae............. 16
9 Apex of metatibia with 23–28 spinules. Metatibia subtriangular, widened towards apex. Prosternal process longitudinally rectangular. Parameres with main lateral teeth very long, without secondary lateral teeth (Fig. 16B). Amazonia of Brazil, Bolivia, Peru, Ecuador, and Colombia ............................................... Tomarus amazonicus (Arrow, 1914)
- Apex of metatibia with 8–17 spinules. Metatibia subrectangular, not strongly widened towards apex. Prosternal process rounded to subquadrate. Parameres with main lateral teeth short to long, with secondary teeth............................ 10
10 Pronotum densely punctate on disc (Fig. 28I). Frontal tubercles transverse (Fig. IH)............................... 11
- Pronotum nearly smooth on disc, without or with minute, very sparse punctures (Fig. 28A). Frontal tubercles conical to triangular (fig. 111 in López-García et al. 2015)................................................................ 13
11 Scutellum with 2 lines of punctures parallel to lateral borders. Inner surface of elytra at apex with small, irregularly distributed tubercles, not forming parallel lines. Galea of maxilla with teeth 5 and 6 well developed (Fig. 4G). Parameres with main lateral teeth short and wide (Fig. 16K). Accessory spine-like lamellae without granules at base (Fig. 22C). Bolivia to Honduras .............................................................................. Tomarus maternus (Prell, 1937)
- Scutellum with or without sparse punctures, not forming parallel lines. Inner surface of elytra at apex with 13–14 parallel lines (stridulatory area). Galea of maxilla with teeth 5 and 6 vestigial (Fig. 4I). Parameres with main lateral teeth long and slender (Fig. 16A, R). Accessory spine-like lamellae with dense, large granules at base (Fig. 22B).......................... 12
12 Apex of parameres slender (Fig. 16A). Bahamas and Cayman Islands ......... Tomarus adoceteus Ratcliffe & Cave, 2010
- Apex of parameres wide (Fig. 16R). United States of America (Florida)........... Tomarus subtropicus (Blatchley, 1922)
13 First interval of elytra smooth or with sparse punctures. Parameres as in Fig. 16G. Mexico to Costa RiI........................................................................................... Tomarus laevicollis (Bates, 1888)
- First interval of elytra strongly punctate, punctures similar in size or smaller than other intervals..................... 14
14 Apex of pygidium strongly dilated in female. Parameres with secondary small teeth joined to main (basal) large teeth (Fig. 16H). Panama ............................................... Tomarus laticaudus López-García & Deloya, 2019
- Apex of pygidium regularly rounded in female. Parameres with secondary, small teeth widely separated from main large lateral teeth (Fig. 16D, I–J).................................................................................. 15
15 Parameres with secondary teeth acute and shorter than main teeth (Fig. 16D). Protibia tridentate with a small, basal denticle. Colombia (Pacific Coast)............................. Tomarus colombianus López-García & Gasca-Álvarez, 2014
- Parameres with secondary and main teeth equal in length and shape (Fig. 16J). Protibia tridentate with a small, basal undulation. Northern Venezuela ...................................... Tomarus maracaiboensis López-García & Deloya, 2019
16 Pygidium completely rugose. Parameres strongly narrowed at apical 4th; lateral medial teeth wide (Fig. 16L). Peruvian Amazonia................................................... Tomarus pilcopataensis López-García & Deloya, 2019
- Pygidium rugose on apical 3rd, disc with sparse, round punctures. Parameres with apex without strong constrictions, sides nearly parallel; lateral medial teeth narrow. Argentina ........................................................ 17
17 Clypeal teeth separated by about 1.5 tooth diameters. Parameres with dorsolateral teeth short, triangular (Fig. 16N)................................................................................... Tomarus pumilus (Prell, 1937)
- Clypeal teeth separated by less than 1 tooth diameter. Parameres with dorsolateral teeth long, arcuate (Fig. 16O).......................................................................... Tomarus roigjunenti Neita & Ratcliffe, 2017
description: Published as part of López-García, Margarita M. & Deloya, Cuauhtémoc, 2022, Cladistic analysis reveals polyphyly of Tomarus (Coleoptera: Scarabaeidae: Dynastinae): new classification and taxonomic revision, pp. 1-119 in Zootaxa 5211 (1) on pages 52-54, DOI: 10.11646/zootaxa.5211.1.1, http://zenodo.org/record/7345007