Pseudotelegeusis meloi sp. nov., the first Telegeusinae from Peru (Coleoptera: Omethidae, Telegeusinae)

Telegeusinae is a small subfamily of Elateroid beetles presently attached to the Omethidae family. Pseudotelegeusis Wittmer, 1976 is composed of three species, two occurring in northern South America and one in Mexico. Here we describe the fourth species for the genus, Pseudotelegeusis meloi sp. nov., collected in a Malaise sample from the region of Madre de Dios, Peru. The new species is diagnosed mainly by the antennae serrate from antennomeres III to X, eyes occupying half of head width in lateral view and vertex occupying 3/5 of head in dorsal view. This new species is close to the other two South American species, P. howdeni Wittmer, 1976 and P. oculatus Wittmer, 1976, according to the serrate antennae and number of ventrites. The three South American species differ from the Mexican species, P. jiliotupaensis Zaragoza-Caballero, 2008, by the different antennae and the number of ventrites, which indicates that the Mexican species should possibly be classified in a different genus. The main morphological characters, including maxillar palpi, tentorial pits and male genitalia, are illustrated, and an updated key to the species of Pseudotelegeusis is given, as well as distribution maps.


Introduction
Telegeusinae is a small subfamily of rarely collected beetles, composed of 20 species in three genera (Fleenor & Taber 2001;Ivie 2002;Zaragoza-Caballero 2015): Telegeusis Horn, 1895, with 16 species distributed from southern United States to Panama (Fleenor & Taber 2001;Zaragoza-Caballero 2015); Pseudotelegeusis Wittmer, 1976, with three species from French Guiana, Trinidad and Tobago, Venezuela, Ecuador and Mexico (Wittmer 1976b;Zaragoza-Caballero 2008); and Pseudokarumia Pic, 1931, with one species from Costa Rica and Panama (Ivie 2002). The phylogenetic position of Telegeusinae is still debated within the Elateroidea superfamily, depending on the analysis (Branham & Wenzel 2001, 2003Bocakova et al. 2007;Hunt et al. 2007). Recent molecular studies point to a relation of the group with the Omethidae (Mckena et al. 2015;Bocak et al. 2018), as a subfamily within the group (Kundrata et al. 2014). Morphological basis for this relationship, however, were not found yet.
Pseudotelegeusis is represented by the following species: the type species, P. howdeni Wittmer, 1976 (French Guiana, Trinidad and Tobago, Venezuela), P. oculatus Wittmer, 1976 (Ecuador) and P. jiliotupaensis Zaragoza-Caballero, 2008 (Mexico). The genus is recognized by the strongly serrate antennae (except for P. jiliotupaensis); the maxillary palpi composed of four palpomeres, the last enlarged; labial palpi composed of one palpomere; and, according to the authors, only one single tentorial pit (Wittmer 1976b;Ivie 2002;Zaragoza-Caballero 2008). So far, the species were only recorded by their original description, except for P. howdeni, which was later recorded for French Guiana (Constantin 2010).
The Peruvian Amazon includes a large subcontinuous area of primary forest, and is considered a priority in terms of global biodiversity inventories (Brooks et al. 2006). The number of species listed from there is increasing every year (e.g. Gonçalves et al. 2014;Cavichioli & Takiya 2012;Chaparro et al. 2007), but it is a race against deforestation, alas important (from 1999 to 2005, for example, around 650 km² were lost annually according to Oliveira et al. 2007), with the reduction of the habitat of still-unknown species.
The goal of this study was to describe a new species of Pseudotelegeusis from the regions of Madre de Dios, Huánuco and Loreto, Peru, to give an account of its intra-specifi c variability, to provide a key to the species of the genus, and to discuss the family's distribution and its rarity in collections. Incidentally, we controlled the character of the tentorial pit and found the presence of two tentorial pits on the ventral face of the cephalic capsule.

Study area
The region of Madre de Dios, Peru, includes around 15% of the Peruvian Amazonian Rainforest, with altitudes from 186 to 3500 m (Portal Ofi cial del Gobierno Regional de Madre de Dios 2015). The fi rst recognized specimen was collected next to the highway "Interoceanica sur", which is near the Bahuaja Sonene National Park (PNBS, acronym in Spanish) (Figs 1A-B, 3E). The PNBS protects a region of 1091.416 ha. It includes vegetation types such as humid forest, submontane humid forest and tropical humid savannah ("Pampas del Heath"). Its climate is constituted by wet and hot summers, reaching 38°C, and cold dry winters, descending to 8°C. The area has an annual precipitation of 2400 mm (SERNANP2018). The holotype was collected in the CICRA biological station, in the Madre de Dios region. Additional paratypes from Madre de Dios, Huanuco and Loreto regions came also from similar habitats of the Amazonian foothills of the eastern cordillera.

Collections and identifi cation
The holotype was preserved in 70% alcohol, then mounted on card, and the paratype specimens were mounted on cards. The specimen deposited in the Universidade Federal do Paraná (DZPR) is preserved in 92% alcohol. Specimens were deposited at the following collections:

Illustrations and dissections
Photographs were taken partly under stereo microscope Leica DFC450 with the Application Suite CV3 multifocus software, partly with a DSLR adapted to a Leica MZ12.5 or to a Cambridge compound microscope, the frames fusion was realised with Helicon Focus Pro. The terminology follows Wittmer (1976b), Zagaroza-Caballero (2008) and Roza et al. (2017). Head capsule, last abdominal segments and genitalia were examined on holotype and paratypes after dissection and inclusion in a water soluble mounting medium. We generated the distributional maps using the software Quantum GIS 2.14.3 (QGIS Development Team 2016) and Data-Fauna-Flora 2017 (Mons University, Belgium).

Diagnosis
Antennae moniliform or serrate, from antennomere III or IV to X. Maxillary palpi 4-segmented, last palpomere enlarged as long as the preceding three together. Labial palpi composed by one palpomere. One tentorial pit, according to former authors (Wittmer 1976b;Ivie 2002;Zaragoza-Caballero 2008), but during the present study we observe two distinctly separated tentorial pits on the ventral face of the head capsule of Pseudotelegeusis meloi sp. nov. (Fig. 3B) and P. howdeni Wittmer, 1976 (Fig. 3C).The initial error by Wittmer (1976b), observing only one tentorial orifi ce, is probably related to the limitations of an optical examination of dry material. His work on the morphological evolution of the tentorium in the Phengodidae family had benefi tted either from dissections of the cephalic capsule or from scanning electron microscope examination (Wittmer, 1976a). We used the classical steps of dissecting, clearing in potash solution, mounting in a drop of syrup solution of dimethyl hydantoin formaldehyde and examination with compound microscope in transmitted light at 200-400 × (see Liberti 2005). In Pseudotelegeusis, we observed that the organization of the tentorium is similar to that of the Phengodidae Distremocephalus texanus (LeConte), as illustrated by Wittmer (1976a: 444, fi g. 28). It consists of two arms separate at the base, basally joined by a bridge, distinct and subparallel in their central portion and obliquely curved against the dorsal surface.

Diagnosis
Head light brown, body overall pale yellow. Antennae serrate from antennomere III to X (Figs 1C, 2A). Eyes occupying half of head width, in lateral view. Vertex occupying ³⁄ 5 of head in dorsal view (Fig. 1D). Elytron reaching the anterior margin of the third abdominal segment, covering the basal half of the folded hind wings (Figs 1A, 1B, 2A).

Etymology
The name meloi is given in honor of Gabriel A.R. Melo, a fellow researcher from the Laboratório de Biologia Comparada de Hymenoptera, Universidade Federal do Paraná, Brazil. Gabriel was responsible for receiving us during our visit to UFPR, and for the loan of the fi rst known specimen of this new species.

Description
Male COLORATION. Body overall pale yellow, except for brown head.
THORAX. Pronotum transverse (Figs 1E, 2B), 1.4 times as wide as than long. Anterior edge regularly rounded, posterior edge more arched. Lateral edges almost rectilinear. Disc slightly transversally convex, smooth, without distinct punctures, bordered by a furrow and a complete rounded bead except in the median fourth of the anterior and posterior margins. Anterior corners with a deep dimple. Elytron 3.5 × as long as wide (Fig. 1F), reaching the anterior margin of the third abdominal segment (Fig. 1A, 1B). Both elytra dehiscent, narrowing towards the rounded tips. The two basal thirds of the elytral surface shiny, shallowly punctate; apical third of elytra rugulose, with a dense vestiture of brown setae inserted in minute vesicles.

Immatures and females
Unknown.

Intra-specifi c variability
The general coloration does not show any variability. Paratypes originating from the region of Madre de Dios do not differ signifi cantly from the holotype.
At a distance of 800 km from the type station, the series of specimens from ACP Panguana (Huanuco) is distinguished by the smaller size and signifi cantly shortened elytra of the specimens, which still remain within the range of variability of the Madre de Dios specimens. All other morphological characters are identical.
At a distance of 1300 km from the type station, specimens from Jenaro-Herrera (Loreto) differ only in the slightly narrower interocular interval of the vertex, the longer eyes, the pronotum more transverse, the shorter elytra. All the other morphological characteristics, including the aedeagus, ensure its unequivocal specifi c identity as P. meloi sp. nov.

Biology and distribution
The holotype of Pseudotelegeusis meloi sp. nov. was collected in September, during the beginning of autumn. It inhabits low altitudinal areas of 260 m in the Peruvian Amazonian Rainforest of Madre de Dios. Paratypes were collected by interception trap, either Malaise traps, or window interception trap. With one series attracted by a UV light trap at the ACP Panguana.

Differential diagnosis
The new species differs markedly from P. jiliotupaensis by the serrate antennae (moniliform in P. jiliotupaensis) and the abdomen with eight ventrites (seven in P. jiliotupaensis). Also, this new species differs from P. oculatus by the antennae serrate from antennomeres III to X (from IV to X in P. oculatus) and the convex posterior margin of pronotum (more pointed medially in P. oculatus). The new species most closely resembles P. howdeni by their similar antennae, but can be distinguished by the yellowish coloration, the protruding eyes, smaller vertex and the straight anterior margin of pronotum (brown coloration, eyes not protruding, big vertex and the anterior margin of pronotum slightly pointed medially in P. howdeni).

Discussion
Telegeusinae are among the most enigmatic Elateroid taxa, with unclear phylogenetic affi nities and little knowledge gathered about their biology. The subfamily is composed of only three genera and 20 species, over half of which were described based on less than fi ve specimens (Horn 1895;Martin 1931;Barber 1952;Allen & Huntton 1969;Zaragoza 1975Zaragoza , 1990Wittmer 1976b;Fleenor & Taber 2001;Zaragoza-Caballero & Rodríguez-Velez 2011;Zaragoza-Caballero 2008, 2015. So far, no female or larvae were described, and males are rare on most collections. However, the number of specimens in the type series of Telegeusinae descriptions has grown signifi cantly in recent years (Zaragoza-Caballero & Rodríguez-Velez 2011;Zaragoza-Caballero 2015). The increase of sampled Telegeusids is due to the use of Malaise and Flight Intercept Traps (FITs), which have been proved as effective ways to collect Fig. 3 these rare beetles. These traps are very successful at collecting small fl ying insects poorly collected otherwise (Hosking 1979). The description of this new species is evidence of the effi ciency these traps in collecting Telegeusid specimens.
The genus Pseudotelegeusis is rather homogenous, both morphologically and geographically, except for P. jiliotupaensis. The three South American species, including the one described here, have serrate antennae, the lateral region of the head posterior to eyes with one to one and a half times the eye length, and eight ventrites. Pseudotelegeusis meloi sp. nov. was recorded from the northern Amazon forest but P. oculatus was collected by a Malaise trap on the fi rst slope of the western cordillera of Ecuador in a small remaining area of the tropical costal humid forest (Wittmer 1976b). Pseudotelegeusis jiliotupaensis has moniliform antennae, the lateral region of the head posterior to eyes twice the eye length, seven visible ventrites, and is distributed in the deciduous tropical forest in Colima, Mexico (Zaragoza-Caballero 2008). The Mexican species has several characteristics of all three genera of Telegeusinae, and was allocated in Pseudotelegeusis due to the number and morphology of the palpi and the presence of a single tentorial pit (Zaragoza-Caballero 2008). However, a complete taxonomic revision of the genera is needed to ascertain the phylogenetic position of the Mexican species.
The genus distribution includes Mexico, French Guiana, Trinidad and Tobago, Venezuela, Ecuador and Peru (Fig. 3D, 3E). Pseudotelegeusis meloi sp. nov. represents the southernmost record for Telegeusinae, which now occurs from the South of United States to Peru. The large forest areas between the species locations may host further new species, both in South and Central America. New collections, using fl ight interception traps or Malaise traps, could greatly increase the species richness of the family.