Careocallus Cherman, 2024

Cherman, Mariana A., Basílio, Daniel S., Clarkson, Bruno, Agostinis, André O., Smith, Andrew B. T., Vaz-De-Mello, Fernando Z. & Almeida, Lúcia M., 2024, New and revised taxa of Neotropical Diplotaxini (Coleoptera: Melolonthidae): do they change the existing relationships? Revisiting systematics with morphological and molecular data, Zoological Journal of the Linnean Society 201 (1), pp. 98-135 : 119-128

publication ID

https://doi.org/ 10.1093/zoolinnean/zlad115

publication LSID

lsid:zoobank.org:pub:E6D9AF7E-F0AD-4656-B2F2-7FBFAA0312B3R

DOI

https://doi.org/10.5281/zenodo.11247715

persistent identifier

https://treatment.plazi.org/id/03D18442-FFD9-FF97-32FB-FC2C5CE3FB15

treatment provided by

Plazi

scientific name

Careocallus Cherman
status

gen. nov.

Genus Careocallus Cherman View in CoL , gen. nov. ( Figs 8–11 View Figure 8 View Figure 9 View Figure 10 View Figure 11 )

ZooBank: urn:lsid:zoobank.org:act:01587959-22AB-49A9-835D-FF7DAD5DF8A2

Type species: Careocallus tehuelche .

Diagnosis

Careocallus is distinguished from all other Diplotaxini genera by the following combination of features: clypeus trapezoidal, coplanar with frons (2:0); anterior margin subemarginate (6:0) ( Figs 8B View Figure 8 , 10B View Figure 10 ); apex of mandible perpendicular to the axis, equal in length or slightly shorter than the labrum in frontal view (156:0) ( Fig. 12A, D View Figure 12 ); antenna with 10 antennomeres (40:0); constriction between pro- and pterothorax (58:1); elytra coarsely punctate, punctures elongate (61:1); three elytral ridges; first gap of ridges on its distal half as wide as the innermost ridge (66:1); sutural ridge extending from the base of scutellum (65:0), not uniform in width along its length (64:1), and angulate on apex (157:1) ( Fig. 14F View Figure 14 ); procoxa without scales on infracarinal surface (69:1); protarsomeres I– III combined as long as or longer than head (79:0); metatibia with apical spurs even in shape (97:0); protarsomere I as long as protarsomere II (80:0); in males all tarsi slender ( Fig. 8C View Figure 8 ), protarsomeres I– III inconspicuously wider than the others (133:0); in females elytra strongly convex ( Fig. 9B View Figure 9 ), hindwings brachypterous ( Fig. 11C View Figure 11 ); subapical callus of elytron inconspicuous ( Fig. 10F View Figure 10 ) or even absent in males ( Fig. 8E View Figure 8 ), completely absent in females ( Fig. 9C View Figure 9 ).

Description

Length: 6.5–14.7 mm; width: 3.5–7.2 mm. Body elongate in males, oval in females; body and elytra plum-coloured to brownish-red. Head: frons swollen; frons and clypeus coplanar; frontoclypeal division weak, outer margin of maxillae straight (14:0), galea with five teeth at the apex; distal palpomere oblong, apex more-or-less acuminate; sensorial surface forming a fovea deep or shallow, varying from not reaching the midline of the palpomere ( Careocallus densicollis Cherman and Smith , sp. nov.) to extending past the midline or reaching the apex ( C. tehuelche ) ( Fig. 8B View Figure 8 ); apex of mandible bifid, perpendicular to the mandible axis ( Fig. 12D View Figure 12 ), and in frontal view equal in length or slightly shorter than the labrum ( Fig. 12A View Figure 12 ); labium quadrate; ligula slightly concave anteriorly; length of ligula shorter than the excavation; labial palpomere I longer and narrower than palpomere II; labrum convex on upper margin and longer than clypeus in frontal view ( Cherman et al. 2017, Fig. 13A View Figure 13 ); antenna with 10 antennomeres, club lighter in colour and slightly longer than the funicle. Prothorax: pronotum wider medially, forming a lateral convexity; pronotal posterior corners in obtuse angle or subangulate, sometimes weakly carinate ( Fig. 8B View Figure 8 ); hypomeron setose, long bristles throughout and few scales on inner margin. Pterothorax: scutellum ogival variable in width; punctate; metaventrite sparsely bristled. Elytra: glabrous, shiny, coarsely punctate; sutural ridge weak around the scutellum and more marked towards its apex, wider along the medial portion; elevated or not, in general unicolorous with the elytron; three elytral ridges more-or-less noticeable, separated by gaps, the first gap equal to or narrower than the second gap; the first gap distally as wide as the innermost ridge, subapical callus of elytron inconspicuous in males, completely absent in females. Legs: procoxae conical, with scattered bristles; protibial surface with two medial longitudinal carinae ( Figs 9A View Figure 9 , 10B View Figure 10 ); protibial inner margin concave and the outer one with three teeth, the apical tooth slightly oblique to the tibial axis (see Cherman et al. 2016: fig. 3E), the basal tooth is always the smallest; the two other protibial teeth equal in size, the three teeth equally spaced; basal articular lobe of metacoxae produced beyond the outer margin of trochanter; mesotibiae cylindrical or subquadrate, with two transverse carinae bearing long setae, mesotibial setae longer than the spines of the apical crown ( Cherman et al. 2017: figs 42–45), the apical carina on mesotibia complete, sometimes very strong forming a ring; pair of apical spurs on apex of mesotibia and metatibia; even or slightly uneven in length, the gap between spurs is equal to the base of one spur; protarsi long, slender; protarsomere I as long as protarsomere II or slightly shorter; all claws bifid and symmetrical, protarsal claws slightly longer than the others, up to one-half the length of the protarsomere V, inferior tooth reduced, raising from the midline of the superior tooth ( Fig. 9D, E View Figure 9 ) or next to its base ( Fig. 10E View Figure 10 ). Abdomen: propygidium slightly visible ( Fig. 10F View Figure 10 ) or hidden by the elytra (especially in females) ( Fig. 9C View Figure 9 ); sparsely bristled; pygidium flat, disc with bristles throughout or only at apex; varying from coarsely to weakly punctate; subquadrate or subtrapezoidal, pygidium twice the length of ventrite V; maximum width does not exceed the distance between the propygidial spiracles; apex of pygidium varies from quadrate, subquadrate to rounded.

Dimorphism

Female: Length: 9.1–12.3 mm; width: 4.7–7.1 mm. Size and body shape: strongly oval, shorter than males. Pterothorax: distance between mesocoxae and metacoxae very short, equal in length to metacoxae or shorter. Elytra: strongly convex, punctures coarser, elytral ridges wider, subapical callus absent ( Fig. 9C View Figure 9 ), hindwings brachypterous ( Fig. 11C View Figure 11 ). Legs: protibia shorter and wider, teeth of outer margin wider; mesotibia sometimes noticeably enlarged towards apex; apical transverse carina on mesotibia and metatibia commonly complete and proeminent; metatibia wider and shorter; protarsomeres as wide as in the other legs. Abdomen: the pygidium may differ from the male in shape, being narrower and slightly longer.

Male: Length: 6.5–14.7 mm; width: 3.5–7.2 mm. Head: club of antenna longer. Pterothorax: distance between mesocoxae and metacoxae longer than the metacoxae. Elytra: slightly convex or flattened dorsally, subapical callus unnoticeable, hindwings normal in size ( Fig. 11A, B View Figure 11 ). Legs: inner margin of metatibia carinate from the medial portion towards apex, depending on the species uniformly straight ( C. tehuelche ) ( Fig. 8D View Figure 8 ) or expanded from subapical portion ( C. densicollis ) ( Fig. 10D View Figure 10 ); apex barely setose along the inner surface; two transverse carinae present posteriorly; the basal carina sometimes very weak, the apical carina incomplete or complete (that is crossing the disc of metatibia), pair of apical spurs even or uneven in length; protarsomeres I and II slightly wider than the others, in C. densicollis also the protarsomere III. Abdomen: more concave than in females. Parameres: basal region ( BR) sulcate at its longitudinal midline ( Figs 8F View Figure 8 , 10G View Figure 10 ), lateral margin, on a plane below expanded ( Fig. 10G View Figure 10 ) or not ( Fig. 8F View Figure 8 ); parameral split on the basal third ( Fig. 10G View Figure 10 ) or in the second third ( Fig. 8F View Figure 8 ); inner margins of parameres straight or convergent at the apex; apex spatulate, with margins rounded or subangulate; in lateral view parameres straight, coplanar with BR or not, sloped from subapical region and flattened on apex ( Figs 8G View Figure 8 , 10H View Figure 10 ).

Remarks on hindwings

Radial sector of the hindwings is more sclerotized in C. densicollis ( Fig. 11A View Figure 11 ), while it is reduced in females of C. tehuelche ( Fig. 12A, B View Figure 12 ). The radial sector is the most important during the flight activity. Moreover, the fold mechanism that involve the RA1 + 2, the RP loop and the MP veins, which is also responsible for the flight ( Kukalová-Peck and Lawrence 1993, 2004), is also reduced in hindwings of C. tehuelche females. This reduction possibly indicates that females of C. tehuelche do not fly.

Etymology

From Latin ‘ careo ’ (be deprived of); ‘ callus ’, (hard skin). The name refers to the absence of the subapical callus from the elytra. Masculine in gender.

Composition: Careocallus tehuelche and Careocallus densicollis .

Distribution and habitats

Careocallus occurs in southern Argentina, from San Luis province (northernmost record 35°34ʹS 65°19ʹW) up to Chubut (42°46ʹS 64°59ʹW). Its distribution encompasses the southernmost part of Pampas and mainly the Patagonian region, from the eastern Andes with wet winters towards the Atlantic dry region.

Careocallus and the other genera

Among all genera of Neotropical Diplotaxini, Careocallus and Liogenys exclusively share the longitudinal inner margin of male metatibia produced [except the clade ( L. tarsalis + L. forcipata )] (143:0),andcoveredwithsetaeoninnersurface(144:0)(variable among Liogenys species). Among the Neotropical Diplotaxini, Careocallus could be morphologically mistaken with Liogenys or Pachrodema . Compared to Liogenys , Careocallus is similar in size, colour, and number of antennomeres (10, as in most Liogenys ). The anterior margin of clypeus is subemarginate in Careocallus , which is uncommon among Liogenys species, though present in L. niger , L. unicolor Evans , and L. rufocastanea Moser ( Cherman et al., 2019) . Careocallus differs from Liogenys mainly in the clypeus trapezoidal ( Fig. 8B View Figure 8 ), without lateral impressions; frons and clypeus coplanar; ocular canthus narrow distally and gradually wider towards the proximal region, at the junction with clypeus (head in shape most similar to Pachrodema ); apex of mandible perpendicular to the axis and almost as long as the labrum (156:0) (in Liogenys and Homalochilus the apex of mandible is in oblique plane to the axis) ( Fig. 13E, F View Figure 13 ); anterior margin of labium with emargination wider than in Liogenys ; labial palpomere I narrower and longer than palpomere II (in Liogenys palpomere I slightly wider and shorter than palpomere II); labrum longer than clypeus in frontal view (39:0) ( Fig. 13A View Figure 13 ) (in Liogenys it is shorter; Fig. 13C View Figure 13 ); pronotum narrower posteriorly than in Liogenys ; and mesotibial setae longer than the spines of the apical crown (as long as or shorter in Liogenys ) (see Cherman et al. 2016:: fig. 3).

In addition to most of the previous features, Careocallus resembles Pachrodema in the head in shape; frons swollen, not forming a concavity with clypeus; and frontoclypeal division present, though weakly marked. According to both implied weighting and equal weighting hypotheses ( Figs 1 View Figure 1 , 2 View Figure 2 ), Pachrodema and Careocallus are not sister-lineages due to the prothorax– pterothorax insertion, less constrained (58:1), inner margin of mesotibia straight, not concave (82:0), and the protibia with basal tooth more than one half shorter than the middle tooth (131:0) (see Cherman et al. 2016: Figs 2D View Figure 2 , 3F View Figure 3 to compare with Pachrodema ).

Careocallus differs from both Liogenys and Pachrodema mainly in the subapical callus of elytron not distinguishable in males, absent in females; sutural ridge of elytra weakly marked around scutellum (65:0) (in Homalochilus it is well marked around the scutellum and in the other Neotropical Diplotaxini raises from the apex of scutellum); first gap of ridges on elytra as wide as the innermost ridge (66:1); apex of sutural ridge angulate (157:1); distance of mesocoxae and metacoxae in females short, as long as the metacoxae; apical tooth of protibia oblique (74:0); all tarsi slender; length of protarsomeres I, II, and III combined as long as or longer than head (79:0); and males with protarsomeres I, II, and sometimes III slightly enlarged (excepting Homalochilus with all tarsi slender, the other Neotropical Diplotaxini also with tarsomere IV of the protarsi and mesotarsi enlarged).

IDENTIFICATION KEY TO CAREOCALLUS SPECIES

1. Body oval; pronotum with punctures homogeneously disposed ( Fig. 8B View Figure 8 ), elytra convex, apex of sutural ridge in 90º ( Figs 8E View Figure 8 , 9C View Figure 9 ); protarsal claw with superior tooth four times the length of the inferior tooth ( Fig. 9D View Figure 9 ); males with inner margin of metatibia straight ( Fig. 8D View Figure 8 )....................................................................................................................................... Careocallus tehuelche

-. Body elongate; pronotum with punctures densely disposed anteriorly ( Fig. 10B View Figure 10 ); elytra flat, apex of sutural ridge in obtuse angle ( Fig. 10F View Figure 10 ); protalsal claw with superior more than six times the length of the inferior tooth ( Fig. 10E View Figure 10 ); males with inner margin of metatibia expanded subbasally ( Fig. 10D View Figure 10 )............................................................................... Careocallus densicollis

V

Royal British Columbia Museum - Herbarium

BR

Embrapa Agrobiology Diazothrophic Microbial Culture Collection

MP

Mohonk Preserve, Inc.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Scarabaeidae

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