Tropopterus Solier, 1849

Liebherr, James K., 2019, Revision of Tropopterus Solier: A disjunct South American component of the Australo-Pacific Moriomorphini (Coleoptera, Carabidae), Deutsche Entomologische Zeitschrift 66 (2), pp. 147-177 : 147

Genus Tropopterus Solier, 1849

Tropopterus Solier 1849: 211; Reed 1874: 58; Chaudoir 1876: 124; Sloane 1898: 471; Sloane 1903: 585.

Tropidopterus Gemminger and Harold 1868: 385 (unjustified emendation).

Type species.

Tropopterus giraudyi Solier by subsequent designation ( Enderlein 1909).

Diagnosis.

Tropopterus may be placed in the Moriomorphini based on: presence of a seta in the mandibular scrobe; frontal grooves present mesad eyes and traversing the frons anteromedially to the frontoclypeal suture; clypeus narrower than distance between antennal insertions; penultimate maxillary palpomeres glabrous, not setose over the entire surface; apical palpomeres fusiform and as long and broad as penultimate palpomere; head with two pairs of supraorbital setae; procoxal cavities closed posteriorly; mesocoxal cavities conjunct; prothoracic leg bearing an antennal cleaner with a distal zone of short, separated setae, and a basal arc of confluent setae that performs the cleaning function (Grade C of Hlavac 1971). The first eight characters will place Tropopterus within Psydrini in the system of Roig-Juñent and Domínguez (2001). The last antennal cleaner character differentiates the Psydrini from Moriomorphini ( Baehr 1998; Liebherr 2020), as Psydrini exhibit a shorter, less well-developed antennal cleaner (Grade B of Hlavac 1971) versus that observed in Moriomorphini . The morphological results conform to phylogenetic hypotheses based on molecular sequence data ( Maddison et al. 1999, 2019).

Within Moriomorphini Tropopterus may be diagnosed by the inversion of the male aedeagus, a character observed in several other Moriomorphini : Mecyclothorax storeyi Moore (1963) of Queensland; and polymorphically within Western Australian populations of Mecyclothorax punctipennis (MacLeay) ( Liebherr and Will 2015). Nowhere else in Moriomorphini does this character define a monophyletic grouping of species. Other characters supporting monophyly of Tropopterus include deep, pitlike paramedial depressions of the mentum, also observed in Meonis spp. of Australia ( Moore 1963; Liebherr 2020). The metathoracic scutellum projects little onto the disc of the elytra, whereas it is more narrowly triangular and elongate in the sister group Pharetis ( Liebherr 2020). The elytral basal groove (when present) meets the lateral marginal depression at a distinct angle, whereas this juncture is more rounded in Pharetis thayerae . Both Pharetis and Tropopterus are characterized by a tooth along the dorsal margin of the humerus. Though the elytral striae vary in configuration among Tropopterus spp., their reduction is derived, and the presence of only the first, or sutural stria in a fully developed condition on the elytral apex is a synapomorphy. All species of Tropopterus are characterized by vestigial flight wings, and the metepisternum is correspondingly foreshortened. That sclerite’s dimensions range from length 1.2 × breadth to length and breadth subequal; length measured along lateral margin and maximal breadth measured perpendicular to that line. Relative to Pharetis , the fourth metatarsomere is more emarginate, with the outer, lateral lobe longer than the inner, mesal lobe. Finally, the setal configuration across the dorsal body is diagnostic, though not synapomorphic, with: presence of both anterior and posterior supraorbital setae; presence of both lateral and basal pronotal setae; presence of the parascutellar setae; absence of any dorsal elytral setae; and presence of both subapical and apical setae near the elytral apex. Consistent with most other moriomorphines there are seven (rarely eight) anterior lateral elytral setae bordering the eighth stria, and six posterior setae: though the posterior two setae of the anterior series, or the anterior two setae of the posterior series may be isolated from their respective series’ partners in T. robustus , sp. nov. Also, males, where known for the various species, have two setae each side of the apical abdominal ventrite, representing a potential synapomorphy for the genus relative to its Australian adelphotaxon, Pharetis thayerae Liebherr (2020). The male aedeagal median lobe is robust, i.e. broad dorsoventrally, with the internal sac flagellar apparatus also large (e.g. Fig. 4A ). The aedeagal median lobe of males, for all species so far examined, bears dense longitudinal pleating across the sclerotized surface surrounding the ostium ( Fig. 4A, C ), with this pleating allowing broad extension of the aedeagal surface during eversion of the internal sac. Females also have two setae each side along the apical margin of ventrite 6 accompanied by four median setae of length subequal to the more lateral setae, these variously arranged in an apically broad trapezoid or in a straight line. The female reproductive tract is characterized by absence of a helminthoid sclerite; a sclerotized projection at the junction of the bursa copulatrix wall, common oviduct, and spermathecal duct ( Liebherr and Will 1998). The derived loss of the helminthoid sclerite, observed across many other moriomorphine taxa, is shared with Raphetis Moore of southeastern Australia ( Liebherr 2020).

Nomenclatural notes.

Although Tropopterus Solier (1849) was used by major authorities throughout the 19th century (see synonymy above), Gemminger and Harold’s (1868) unjustified emendation Tropidopterus was adopted by Enderlein (1909), Moore (1963), and subsequently followed by Baehr (1998). The original spelling of Tropopterus has also been used more recently ( Straneo 1954; Roig-Juñent and Domínguez 2001; Maddison and Ober 2011; Larochelle and Larivière 2013). Though both variants have been used, the original spelling predominates and so the unjustified emendation Tropidopterus cannot be considered "in prevailing usage" ( ICZN 1999, Article 33.2.3.1). Thus Tropidopterus must be rejected in favor of the original spelling.

In addition to the three Tropopterus spp. described by Solier (1849), Germain (1911) listed "T. plicicollis" ms. name, as an undescribed species held in the Museo Nacional de Historia Natural, Santiago, Chile, assigning it his "N.os del Catálogo primitivo" entry 500. This combination was never validly described ( Lorenz 2005). However a specimen labelled as per Germain’s protocol ("459 / Catapilcanus / P. G. (ined.)") was described as Merizodus catipileanus by Jeannel (1962). That name is synonymized below with T. montagnei Solier. Germain’s (1911) list also includes undescribed specimens labelled with his catalog numbers 458 and 460, bracketing the number assigned to “Catapilcanus.” Germain assigned those numbers to his manuscript names Trechus ebeninus and Trechus araucanus , with Jeannel subsequently describing those specimens as Trechisibus araucanus ( Jeannel 1962: 562) and Trechisibus ebeninus ( Jeannel 1962: 577). Thus, some of the undescribed Germain (1911) material was used by Jeannel as the basis for new species he described in 1962, but there is no evidence that any specimens assigned to "T. plicicollis", catalog entry 500, were part of Jeannel’s working material, nor was Germain’s name validated in any subsequent publication. Thus Germain’s (1911) "Tropopterus plicicollis (P. G. ined.)" has no nomenclatural standing.

Straneo (1954) described Tropopterus peruvianus from two specimens (Sivia, Peru, 13-v-1936, 520 m el.) collected during the Südperu-Expedition of the Naturhistorisches Museum, Hamburg. Although Straneo’s description was published in 1954, the material had been originally described in 1942, with the specimens returned to the Hamburg museum and subsequently destroyed in the Allied firebombing of 1943. That the types of this species were lost in the destruction of the museum was documented by Weidner (1976; Dr. M. Husemann pers. comm.). Straneo (1954) recorded the female type used as the basis for the description as being of 8 mm body length. His diagnosis for T. peruvianus , translated from the Italian, follows:

"It differs from T. giraud[y]i Sol. by the basally non-sinuate pronotum; it also has distinctly obtuse pronotal basal angles; the 1st stria is strongly impressed from approximately 1/6 of the elytra length, immediately commencing as a distinct impression and not with isolated punctures; the eighth stria is about as long as the 1st; the third interstria has a small puncture present the apical half; the two basal antennal articles extend beyond the pronotal base, etc. From T. duponcheli [i] Sol. it differs by the first and second striae stria reaching the elytral base, and because the lateral pronotal [margin] is very gradually enlarged from the anterior setal pore towards the base."

This diagnosis does not fit any of the species treated below. Indeed the presence of a puncture in the third interval does not fit the diagnosis of Tropopterus , suggesting phylogenetic placement outside the presently treated taxa. Thus T. peruvianus Straneo is to be treated as an available nomen dubium with its identity to be stabilized through new collection and designation of a neotype.

Figures

Figure 4. Male aedeagal median lobe, left view, and antecostal apodeme and tergite of abdominal IX, dorsal view. A-D. T. canaliculus; Malleco Prov., P. N. Nahuelbuta. A, B. (FMNH). C, D. (OSAC). E-G. T. duponchelii; Arauco Prov., Caramavida. E. (NMNH). F-G. (MCZ). For abbreviations used to label structures see Table 1.