Review of the Inca irroratus species group with description of two new species of Inca LePeletier & Serville, 1828 (Coleoptera, Scarabaeidae, Cetoniinae)

The Brazilian endemic irroratus species group of the genus Inca (Scarabaeidae, Cetoniinae) is defi ned and described. This species group is composed of Inca irroratus Chevrolat, 1833 and two new species: I. axeli sp. nov. and I. neglectus sp. nov. One new synonym is proposed: I. irroratus Chevrolat, 1833 = I. burmeisteri Burmeister, 1844 syn. nov. To guarantee nomenclatural stability, a neotype is designated for I. irroratus and a lectotype for I. burmeisteri. A key to all species of Inca and a map with the distribution of the irroratus species group are provided.

Phylogenetic studies based on morphological and molecular data of immature stages and adults of some species recovered the tribe as monophyletic (Morón & Vaz-de-Mello 2007;Micó et al. 2008;Šípek et al. 2009, 2016. Tauzin & Arnaud (2019) provided remarks on the genera Inca and Golinca and presented a study on biology and distribution of species. Tauzin & Arnaud (2019) updated data on species occurrence, but did not include information formerly made available in several studies (e.g., Morón 1983;Di Iorio 2013;Seidel et al. 2018). The authors also presented a discussion on the larval stage of species of Inca and data on the life cycle of I. bonplandi (Gyllenhal, 1817), I. clathratus sommeri Westwood, 1844, andI. pulverulentus (Olivier, 1789), but omitted recent morphological studies that compare the structures and chaetotaxy of third-instar larva of these species (Morón 1983(Morón , 1995Costa et al. 1988;Sousa et al. 2018). Moreover, they proposed the synonymy of Incini with Osmodermatini based on general similarities of life cycle and on morphology of Osmoderma and Inca. The synonymy proposed did not take into account the diagnoses given by Krikken (1984) (i.e., eye-canthus angulated in front, profemur with a distal tooth in the inner area and protibia with internal face with proximal emargination) and the phylogenetic hypotheses already proposed (Morón & Vaz-de-Mello 2007;Micó et al. 2008;Šípek et al. 2009, 2016Šípek & Král 2012).
Currently, the genus Inca includes 6 species and 3 subspecies (Seidel et al. 2018): I. besckii Burmeister & Schaum, 1840, I. bonplandi (Gyllenhal, 1817, I. burmeisteri Burmeister 1847, I. clathratus clathratus (Olivier, 1792, I. clathratus quesneli Boos & Ratcliff e, 1985, I. clathratus sommeri Westwood, 1844, I. irroratus Chevrolat, 1833, and I. pulverulentus (Olivier, 1789. The taxonomic history of the newly defi ned irroratus group (see Results) is complicated, leading to most museum specimens being misidentifi ed. Chevrolat (1833) described I. irroratus based on a female specimen recorded from Rio de Janeiro State, Brazil which was subsequently illustrated by Gory & Percheron (1833) in the same year. Burmeister (1842) described the male of I. irroratus, however later (Burmeister 1847) claiming that this was based on a misidentifi cation stated: "Inca irroratus. Page 708. -Under this name 2 species are united, which I received in the previous year both directly from Brazil from Mr. Bescke and thus learned to diff erentiate safely. Mr. Bescke had recognized their diff erences very well, and the one, if it should still be undescribed, was given my name. I let them follow here under this name". Subsequently, Burmeister (1847) described Inca burmeisteri updating his 1842 redescription to this new species. Furthermore, he redescribed Inca irroratus based on the material of the second species provided by Bescke. After studying the description by Chevrolat (1833) and the illustration by Gory & Percheron (1833), we conclude that Burmeister's (1842) description of Inca irroratus was indeed correct and therefore leading to I. burmeisteri becoming a junior synonym of that species. Inca irroratus sensu Burmeister (1847) is therefore still an unnamed species that we here describe as Inca neglectus sp. nov.
All species of Inca are distributed in Brazil, however species of the irroratus group are so far only known from Nova Friburgo, Rio de Janeiro State, Ouro Preto, and Minas Gerais State (Seidel et al. 2018). The distribution of species of Inca and our knowledge on the morphology of the genus will be expanded in this work, which describes an additional new species I. axeli sp. nov. that occurs in the southern and southeast region of Brazil in Paraná, Santa Catarina and São Paulo States (Fig. 5). Moreover, for the fi rst time a key to all the species of the genus is provided.

Collections
The material cited is deposited in the following collections (curator(s) in parentheses):

Diagnosis
The genus can be distinguished from other genera of Incini by the following combination of characters: dorsal surface of pronotum covered with waxy velvet like secretion and setigerous punctures with waxy macula (waxy secretion absent in Archedinus, Coelocratus, Golinca and Pantodinus); clypeus of male with divergent lateral horns (parallel horns in Golinca; median horn in Pantodinus; absent in Archedinus and Coelocratus) with inner area densely setose.

H
. Surface of frons with waxy secretion on disc and setigerous and heterogeneous punctures with light yellow waxy macula; short yellowish setae near to supraocular area; lateral portion of epistomal suture distinct near to canthus. Canthus angulate. Clypeus densely punctate with posterior dorsal margin projecting forward; distal area with divergent lateral horns slightly projecting forward and upward; inner area of horns densely setose, setae long and yellow. Labrum transverse. Mandibles with molar lobe rounded and striated; right molar lobe convex; left molar lobe concave. Maxillae setose; cardo with proximal area densely punctate with long yellow setae; galea inwards projected and with brushlike setae. Hypopharynx with long setae. Labium transverse, deeply and densely punctate; punctures with long yellow setae; anterior margin of mentum emarginated. Antennae with 10 antennomeres; club fusiform composed of three antennomeres.
L . Profemur with an inner distal tooth. Protibia with a posterior distal tooth and an inner proximal emargination; spur short. Protarsomeres II-IV with inner striae. Mesotibia with one short and bifurcate spur; transversal carina I with stout setae. Outer posterior angle of metacoxa rounded. Metatibia with transversal carina I with stout setae.

A
. Spiracle VII placed near to anterior margin of sternite. Sternite VIII (last exposed sternite) with a rounded fovea on anteriomedian area. Propygidium totally or partially covered by resting elytra. Pygidium posterior margin parabolic.

T
. Aedeagus: apodeme of phallobase larger than phallobase. Parameres glabrous and with an outer distal process.

B
. Length 27-50 mm; width across humeri 10-17 mm. The morphology of females of Inca is very similar to the male, except by: posterior area of frons with waxy secretion. Clypeus without horns; anterior angles rounded; frontal area elongated. Outer teeth of protibia larger than in males. Transversal carinae I of meso-and metatibia well-marked; mesotibia with two long and simple spurs. Paraproct distinct.

Remarks
As observed in some works (e.g., Ricchiardi 2002;Morón & Vaz-de-Mello 2007;Seidel et al. 2018), the species of Inca can be distinguished from the other members of the tribe Incini mainly by the male with divergent lateral horns with internal face densely setose with long setae and elytra with yellow waxy maculae. In the brachycerous males the outer angles of clypeal horn can be indistinct in some species.

Distribution
From Tamaulipas in Mexico to Paraguay and northern Argentina.  Step 16 separates the females of I. clathratus s. str. to I. clathratus quesneli. However, the morphology of these species is not informative for the distinction of these taxa. Beyond geographic distribution the females of I. clathratus quesneli are usually bigger than I. clathratus s. str. and can have bluish black tegument coloration beyond the dark green, black or brownish black coloration of I. clathratus s. str. Further studies are needed to better clarify the taxonomy of these species.

Diagnosis
The species of the irroratus group can be distinguished from other species groups of Inca by: outer dorsal margin of clypeal horns of males with an acute or rounded tooth (this tooth is outwardly directed); distal area of parameres acuminate; clypeus of females with a posteromedian process and disc convex; medial tooth of the anterior margin rounded (see Table 1). nov. and I. irroratus) and the outer distal process of parameres long and acuminate (long and rounded in I. neglectus sp. nov. and short and rounded in I. irroratus) (see Table 2).

Etymology
It is a pleasure for the last author to name the species after Axel González Gallardo in gratitude for the last years together and all his support.
C . Reddish brown with dark green heterogeneous spots, dorsal surface with green metallic refl ections; legs and meso-and metathorax bright reddish brown (Fig. 1A-C, P). dorsolateral tooth long and acute (Fig. 1P).
T . Lateral margin of pronotum strongly sinuous; lateromedial area with elongated and irregular fovea; longitudinal groove shallow; posterior angles acute (Fig. 1A-C). Anterior prosternal process acute, projected and densely setose in median area. Anterolateral area of scutellar shield punctate. Elytra with yellowish grey heterogeneous waxy maculae covering all surface and two large maculae in medial area (Fig. 1A).

Diff erential diagnosis
Inca neglectus sp. nov. is very similar to I. axeli sp. nov. in that both species have clypeal horns in males with dorsolateral tooth long and acute (short and rounded in I. irroratus), posterior angles of pronotum acute (rounded in I. irroratus), medial area of elytra with large waxy maculae (absent in I. irroratus), and posterior tooth of protibia long and acute (short and rounded in I. irroratus). Inca neglectus sp. nov. has the inner dorsal carina of clypeal horns gradually interrupted (abruptly interrupted at apex in I. axeli sp. nov.) and the outer distal process of parameres long and rounded (long and acuminate in I. axeli sp. nov. and short and rounded in I. irroratus) (see Table 2).

Etymology
The species epithet comes from the Latin word 'neglectus' referring to the species being neglected taxonomically since Burmeister fi rst described it, but did not name it, in 1847.

Material examined
Holotype BRAZIL -Rio de Janeiro • 1 ♂; "Bras. . Reddish brown with dark green heterogeneous spots, dorsal surface with weak green and orange metallic refl ections; legs and meso-and metathorax with reddish brown bright colour (Fig. 1F-H, Q).

H
. Surface of frons with dark green and dark reddish-brown waxy secretion; clypeal horns with anterior area of inner dorsal carina gradually interrupted at apex; dorsolateral tooth long and acute (Fig. 1Q). T . Lateral margin of pronotum strongly sinuous; lateromedial area with elongated and irregular fovea; longitudinal groove well marked; posterior angles acute (Fig. 1I-H) Outer distal process of parameres long and acuminated long and rounded short and rounded acute, projected and densely setose in the median area; can be acute or rounded and little or strongly projected. Anterolateral area of scutellar plate punctate. Elytra little maculated with light yellow waxy maculae covering all surface (Fig. 1F).
A . Fovea of sternite VII strongly marked. Disc of pygidium densely punctate, lateral area with well-defi ned punctures.
M (males). Body length 33−42 mm, width 14−17 mm. Head. In brachycerous specimens the dorsolateral tooth can be rounded and reduced in size.
Female B (Fig. 2E-G). Length 40-42 mm; width across humeri 16-18 mm. Colour of waxy secretion of elytra surface varies from reddish brown to dark reddish brown with waxy maculae that can vary from light yellow to gold yellow colour.

Type locality
Nova Friburgo, Rio de Janeiro State, Brazil.

Diff erential diagnosis
Inca irroratus can be distinguished from the other two species of the group by: females with clypeus bearing a medial rounded fovea (fovea absent in I. axeli sp. nov. and I. neglectus sp. nov.); medial tooth well developed (almost indistinct in I. neglectus sp. nov.); clypeal horns in males with dorsolateral tooth short and rounded (long and acute in I. axeli sp. nov. and I. irroratus); pronotum with posterior angles rounded (acute in I. axeli sp. nov. and I. neglectus sp. nov.) and lateral margin slightly sinuous and deeply crenulated (strongly sinuous and shallowly crenulated in I. axeli sp. nov. and I. neglectus sp. nov.); posterior tooth of protibia short and rounded (long and acute in I. axeli sp. nov. and I. neglectus sp. nov.); epipleuron with irregular and rounded marks on median area (indistinct marks in I. axeli sp. nov. and I. neglectus sp. nov.); outer distal process of parameres short and slightly rounded (long and acuminated in I. axeli sp. nov.; long and rounded in I. neglectus sp. nov.) (see Table 2).

Type locality
Rio de Janeiro, Brazil.

C
. Reddish brown; dorsal surface with metallic refl ections; legs and meso-and metathorax with reddish brown bright colour (Fig. 1K-M, R).

H
. Surface of frons with reddish brown waxy secretion; clypeal horns with inner dorsal carina weak, anterior area gradually interrupted at apex; dorsolateral tooth short and rounded (Fig. 1R). T . Lateral margin of pronotum slightly sinuous and deeply crenulated; lateromedial area with grooved fovea; longitudinal groove shallow; posterior angles rounded (Fig. 1K-M); anterior prosternal process evenly rounded, projected and densely setose in median area. Scutellar shield punctate in anterolateral area. Elytra with light yellow waxy maculae covering all surface; epipleuron with irregular and rounded marks on median area (Fig. 3F).

Remarks
The holotype of I. irroratus cannot be found in the Muséum national d'histoire naturelle (Paris, France) or in the Natural History Museum (BMNH, London, United Kingdom) and we therefore consider it lost. The description by Chevrolat is rather general and does not allow to precisely identify the species. According to Chevrolat, the species is "bearing a very short median horn preceded by the transverse carina", a combination of characters none of the two species in question possess. Females exhibit an elevated carina on the head only in one species (Fig. 2O), whereas the other (Fig. 2N) only possesses a cone-shaped tubercle. None of the species have a horn. Additionally, based on the illustration of the type of I. irroratus by Gory & Percheron (1833), which lacks carina and horn, the female has a strongly crenulated pronotal margin and a medial tooth in the clypeal margin. To fi x the identity of I. irroratus, we designate a male neotype (conspecifi c with females possessing the aforementioned characters) from BMNH ( Fig. 1K-O, R) from the type locality (Rio de Janeiro).
Not knowing the exact number of syntypes and their depositories and to guarantee nomenclatural stability, we designate a male lectotype for I. burmeisteri from the syntype series deposited in MLUH. The lectotype of I. burmeisteri is conspecifi c with I. irroratus, and therefore I. burmeisteri becomes a junior synonym. For I. irroratus sensu Burmeister (1847), see the description of I. neglectus sp. nov.

Discussion
For the fi rst time, the type material of the irroratus group was reviewed and species identities could be established, leading to the synonymy of I. burmeisteri with I. irroratus. The designation of a neotype for I. irroratus and the lectotype designation for I. burmeisteri stabilise the taxonomy and make them identifi able for the fi rst time for over 170 years. Two additional distinct species, I. axeli sp. nov. and I. neglectus sp. nov. which were usually identifi ed as I. irroratus or I. burmeisteri in entomological collections, are described.
Inca axeli sp. nov. has the widest distribution with respect to the other two species of the group, and specimens are easily found in museum collections. By contrast, I. neglectus sp. nov. and I. irroratus are more restricted in distribution and specimens are scarce in collections. Inca irroratus is only known from Rio de Janeiro where it co-occurs with I. neglectus sp. nov. Inca neglectus sp. nov. has the northernmost distribution of the group and is found in Espírito Santo and Minas Gerais as well. All species seem to be associated with Brazil's Atlantic Forest ecosystem (Mata Atlântica). All species of Inca have more affi nity with humid forests such as the Atlantic Forest and Amazon Forest. Between these two biomes there is an extensive corridor of open and dry vegetation called "the diagonal of open formations" or "dry diagonal" formed by the biomes of the Caatinga, Cerrado and Chaco (Vanzolini 1963;Fernandes et al. 2002;Carvalho & Almeida 2011). There are few records of species of Inca in dryer biomes as the Cerrado and Caatinga. Moreover, the ongoing deforestation of humid biomes as Atlantic Forest makes these species highly vulnerable to extinction, which may also explain the diffi culty of fi nding species in the northern coastal region.
The diffi culty in fi nding material of these species may have contributed to the abovementioned identity confusion. The present study contributes to a better understanding of the morphology of the irroratus species group, but our knowledge on the biology of these species remains sparse. Studies on the morphology of immature stages and data on the behaviour of adults can help to increase the knowledge about these beetles and provide important information for the taxonomy and phylogeny of Incini.