Review and new species of Tiferonia Darlington, 1962 (Carabidae, Abacetini)

Abstract Darlington described Tiferonia based on T. parva from New Guinea. In this review, Tiferonia leytensissp. nov. is described from Leyte Island, Philippines, Tiferonia schoutedeni (Straneo, 1943) comb. nov. is transferred from Melanchrous Andrewes, and inclusion of Tiferonia brunnea (Jedlička, 1935) in the genus is confirmed. Characteristics of Tiferonia and genera that have been proposed as closely related to Tiferonia are discussed and a unique character, the post-ocular sulcus, shared among species of Tiferonia and Holconotus is proposed as a synapomorphy for these two genera. A key to identify adults of the four species of Tiferonia is provided.


Introduction
described the genus Tiferonia for two species from New Guinea and the Philippines but subsequently there have been no publications dealing with any additional specimens, species or taxonomic issues in the genus. Outside of checklists or catalogs, only a few papers have mentioned the genus as part of some larger study or peripheral to the principal paper topic. These typically only note the genus to distinguish it from of other genera, note its inclusion in abacetines or Loxandrini auctorum, or remark on its presence in the New Guinea fauna (Darlington 1962(Darlington , 1971Allen and Ball 1979;Allen 1982;Will and Park 2008;Will and Kavanaugh 2012). Specimens are quite rare in collections and there are no current efforts to collect in areas where species may exist using methods likely to obtain more material. This creates the very familiar problem of having only small numbers of specimens for study. During my recent investigations of various Abacetini genera and other Harpalinae that may have a relationship to abacetine taxa, including Darlington's carabid specimens at the Museum of Comparative Zoology, it became apparent that there were several issues that need to be addressed in order to improve the state of the taxonomic understanding of Tiferonia with regard to species membership and possible phylogenetic relationships of this genus to other genera.

Material and methods
Material examined. Specimens were examined from the following collections: Locality information for holotypes of the species described here is verbatim. Text as it appears on the labels is contained in quotation marks. The text for each label is delimited by double forward slash marks.

ANIC
Images. Habitus photos of beetles were taken as image stacks that were aligned and assembled with Helicon Focus version 5.3 and image files were edited to enhance clarity using standard image editing software.
Dissection and measurements. Male genitalia were prepared using the same methods as Will (2002). Measurements were made using an ocular reticle. Standard body length (sbl) is the sum of the distance from the base of the labrum to just anterior of the occipital suture + the length of the pronotum along its midline + the length of the left elytron from basal margin where it meets the scutellum to the apex of the elytron. The width of the elytra is the widest point viewed dorsally. The ocular ratio is the width over the eyes divided by the width between the eyes measured at the level of the anterior supraocular setae, viewed dorsally. Measurements and ratios are given for the type specimen and then a range of all specimens measured is given in brackets.
Generic diagnosis. With a combination of typical abacetine characters such as clearly defined frontal impressions on the head; deeply impressed, linear basolateral pronotal impressions; no angular base of stria 1 on elytra; setose puncture at the base of elytral stria 2; well-developed elytral plica; metacoxal sulcus sinuate; abdominal ventrites without transverse sulci; ostium of aedeagus dorsal; and aedeagus left side dorsal in repose. Recognizable from other abacetine genera that share the character states listed above by the combination of deep post-ocular sulcus ( Fig. 1), smooth elytral margins, and lack of elytral discal setae.
Genus characteristics. Small size beetles (3.8-4.3 mm), castaneous or darker, nearly piceous colored, parallel sided, somewhat convex body form; apical segment of labial palpi elongate and fusiform. Mentum narrow triangular, shallowly emarginate; epilobes long and narrow, not prominent; median tooth prominent and entire, not reaching tips of lobes, mentum paramedial pits absent; paraglossae short, glabrous; submentum narrow, posteriorly sculpted; antennae of moderate length, somewhat thickly filiform, three basal segments glabrous except for apical ring of setae; postocular orbits moderately pronounced, with deep post-ocular sulcus (Fig. 1). Elytra free, lateral margin smooth; border entire across base; parascutellar stria present, joined to stria 1; 13-15 umbilicate setae in stria 8; hind wings fully developed; humeri obtusely angled with very small, usually sharp denticle; anterior tarsi of male with three basal segments narrowly dilated and squamose beneath. Aedeagus ( Fig. 2) with orifice on dorsum; parameres conchoid, the right smaller than the left. Diagnosis. Very similar to T. leytensis but distinct from that species by the form of the pronotum, which is broad and straight onto the base and the form of the male genitalia (Figs 2, 3).  Type locality. Estimated to be centered on 14.1346N, 12.1955E, south east of Calamba.

Tiferonia parva Darlington, 1962
Diagnosis. The single pair of supraorbital setae distinguishes this species from all other species of Tiferonia.
Etymology. The specific epithet leytensis is based on the type locality and is treated as an adjective.
Notes. In his discussion of the species of Tiferonia, Darlington (1962: 561) states that T. brunnea from the Philippines is distinguished by having only a single pair of supraorbital setae and then states that he has a series of that species from Leyte Island. However, this appears to be an error. Among Darlington's specimens at the MCZ he has a series from Leyte Island, but they all have two pairs of supraorbital setae and are otherwise distinctly different from T. brunnea. These specimens comprise the holotype and paratypes of T. leytensis. Darlington (1962) noted that Tiferonia was "superficially similar to Melanchrous." Melanchrous was treated as a member of Oodini by Chaudoir (1883) but then moved to Melanchitonini by Straneo (1962) and has remained in that tribe in recent catalogs (Lorenz 2005a, b;Bousquet 2012). The holotype of T. parva bears a determination label written by Straneo from 1953 with "gen. Melanchrous Andr.," which is likely what suggested this comparison to Darlington. He then points out that Melanchrous from southeast Asia and the Malay Archipelago have protarsomeres with densely pubescent pads ventrally, similar to what is found in some melanchitonines and oodines, not biseriately squamulose as in Tiferonia and other abacetines. I have examined types or confidently identified specimens of all Melanchrous species except for one of the three the African species, Melanchrous celisi Straneo, 1962. All examined Melanchrous spe-cies differ from T. schoutedeni by having protarsomeres with densely pubescent pads ventrally, not squamulosely biseriate. Additionally, no species of Melanchrous has the post-ocular sulcus found in Tiferonia and Holconotus (Fig. 1). The type specimen of M. celisi could not be located (S. Hanot in litt.) and I have not seen any specimens that agree with Straneo's description of the species. Straneo described M. celisi in comparison to T. schoutedeni, to which it is similar in having a reduced number of impressed striae, but no character states were reported that can verify or refute its placement in Melanchrous.

Possible evolutionary relationships of Tiferonia
Tiferonia and Holconotus are both abacetine genera that appear to be close relatives. Darlington (1962) included Jedlička's brunneus in Tiferonia while noting that Holconotus (= Fouquetius) has "dentate humeri and serrate elytral margins," which he states Tiferonia does not. While it is correct that all Holconotus have these states, it is not the case that the humeral tooth is lacking in Tiferonia. The tooth is slightly smaller and, in some cases, more rounded than typically observed in Holconotus, but always present. The humeri in Melanchrous (see above) is fully rounded, with no suggestion of a tooth. The presence of the serrate elytral margin is likely a synapomorphy for Holconotus species, excluding Tiferonia. The shared post-ocular sulcus appears to be a good synapomorphy for a sister-group relationship for Tiferonia and Holconotus. No other genera of Abacetini, and to my knowledge no other carabids, have the post-ocular sulcus as in these two genera.

1
Elytron with eight striae impressed from the apex to or nearly to the base ...2 -Elytron with only the first three striae impressed from the apex to, or nearly to the base (Fig. 8) Pronotum lateral margins slightly sinuate in the basal third, base notably narrower than elytra (Fig. 4). Male aedeagus wide and sharply narrowing at tip in ventral view (Fig. 2). The Philippines ............. Tiferonia leytensis sp. nov. -Pronotum lateral margins nearly straight in the basal third, base nearly as wide as elytra (Fig. 5). Male aedeagus narrow and blunt at tip in ventral view (Fig. 3) Darlington, 1962