The genus Trichocnemis LeConte, 1851 (Coleoptera, Cerambycidae, Prioninae)

Abstract The history of the genus Trichocnemis LeConte, 1851 (Coleoptera, Cerambycidae, Prioninae) is discussed. Its taxonomic status in relation to the genera Ergates Audinet-Serville, 1832 and Callergates Lameere, 1904 is clarified. The synonymy of Macrotoma californica White, 1853, Macrotoma spiculigera White, 1853, and Trichocnemis spiculatus LeConte, 1851 is confirmed. A key to all three genera and their species is provided.


Introduction
Th e prionine genus Trichocnemis has not been formally recognized in North America since it was placed in synonymy with Ergates by Linsley (1962). While the two genera share several characters, and are likely related (Nishio 1956), many characters distinguish the species in these two genera. Earlier authors (Lameere 1901, Casey 1912 considered Trichocnemis a subgenus of Ergates, as was Callergates. More recent authors consider all three as separate genera (Villiers 1978, Jeniš 2001. "thorace scabro, dorso antice bicalloso, spiculis lateralibus valde acutis, apicali basalique majoribus, thorace latioribus"; "the elytra show some indications of costae"; and "the joints of the antennae are marked with a few scattered punctures." However, the type specimen deposited in the Museum of Comparative Zoology (MCZ) is a male (MCZWeb 2009). Th ere is little doubt that LeConte (op. cit.) based his description on a single specimen, since he indicated only a single measurement, stating: "the specimen appears a little immature." In males, the tibiae are not clearly fi liform, the prothorax is not scabrous and has well-marked depressions (a character omitted by LeConte), the pronotal callosities are less pronounced than in females, the lateral spines of the pronotum are much less prominent than in females, and the proximal antennomeres are strongly and abundantly punctate. In the type specimen ( Fig. 1), the elytra show clear carinae, a character that does not agree with the original description.
Although the holotype label of Trichocnemis spiculuatus in the MCZ indicates "Ergates", and not Trichocnemis, it is believed that LeConte himself changed the label after having transferred the species to the genus Ergates. Th is is consistent with other Le-Conte specimens in which the labels indicate diff erent names that the original taxon, for example: Mallodon gnatho LeConte, 1858, which have labels with LeConte's writing, [Mallodon (Nothopleurus) gnatho // Lec. dentiger Lec.]. Other specimen labels are clearly not written by LeConte (vide Mallodon mandibularis Gemm.).
Th e genus Ergates was established by Audinet-Serville (1832) to accommodate a single species: Prionus serrarius Panzer, 1793 (= Cerambyx faber Linnaeus, 1761). Among the many characters used to defi ne the genus, Audinet-Serville (op.cit.) listed: legs without internal spines; antennae fi liform, similar in both sexes, longer than the body in male, and reaching more or less the middle of elytra in female; antennomere III longer than IV-V together; prothorax fi nely crenulated laterally in male, more distinctly in female; mandibles and mentum glabrous; legs of medium length, the prolegs longer than the others. White (1853) synonymyzed Trichocnemis under Macrotoma Audinet-Serville, 1832, but this nomenclatural act was not accepted or used by any later author. White (op.cit.) also did not explain why, in his opinion, that genus was synonymous of Macrotoma.
LeConte (1854) then synonymyzed Trichocnemis with Ergates, stating: "Trichocnemis Lec. (Journ. Acad. 2d, 2, 110) is not suffi ciently distinct from Ergates; the Californian species must therefore be called E. spiculatus." Later, LeConte and Horn (1883) pointed out the same observation of Trichocnemis and placed Ergates in the tribe Ergatini. However, the characters used to defi ne Ergatini (sensu LeConte and Horn) apply primarily to Ergates (= Trichocnemis) spiculatus, and largely excludes Ergates faber (Linnaeus, 1761) (Fig. 2) and Callergates gaillardoti (Chevrolat, 1854) (Fig. 3). Le-Conte and Horn (op.cit.) stated: "the tribe is easily recognized by the prothorax being much broader in the male than in the female, and fi nely punctured; in the latter sex the sculpturing is very coarse, and the small teeth of the lateral margin are longer and more acute. Th e head is small, the eyes reniform and coarsely granulated; antennae  11-jointed, slender, two-thirds the length of the body in the ♂, about half the length of the body in the ♀, rough with elevated punctures, with the 3rd joint as long as the three following united; poriferous spaces on the 3rd joint small inconspicuous, on the under surface near the distal end, gradually becoming larger, until the outer joints become entirely poriferous, and irregularly reticulated with fi ne elevated lines forming elongate cells, which are much less distinct, and in fact hardly to be seen in the male." Th is tribal description excludes E. faber (Fig. 2) because the head is somewhat large, especially in males; the antennae surpass the elytral apex in males; antennomere III is (at most) as long as IV-V together; the pronotum lacks lateral spines in both sexes, and is not clearly wider in males than in females. Callergates gaillardoti can be unsatisfactorily included, because the antennae is somewhat longer than two-thirds the length of the body in male, the antennomere III is shorter than IV-VI together in both sexes, and the teeth of the lateral margin are not "small" in the female.
Lacordaire (1869) did not revalidate Trichocnemis, although it is clear he did not agree with LeConte's (1854) synonymy stating: "Le genre Trichocnemis de M. J. L. Le Conte, établi primitivement sur la femelle d'une espèce (3) de Californie, a étè reconnu, plus tard, par se savant entomologiste, comme devant rentrer dans celui-ci. Cette femelle, que j'ai sous les yeux, diff ère notablement, sous le rapport du facies, de celle de faber, et a celui d'une Macrotoma; son prothorax est multiépineux sur les côtés et les épines sont longues et irrégulières. D'après la description qu'en donne M. J. L. Le Comte, le mâle diff érerait également, d'une manière sensible, de celui de l'espèce européenne." LeConte (1869) was the fi rst author to attribute subgeneric status to Trichocnemis, when he listed "Ergates (Trichocnemis) spiculatus Lec.," but did not off er an explanation of this new status. Casey (1890) maintained Trichocnemis as a subgenus of Ergates based on the length of the antennae, anterior legs, and denticulation of the sides of the prothorax, stating: "It seems proper therefore that the name Trichocnemis Lec. should be preserved, if not with full generic value, at least as a subgenus." Lameere (1901) considered Trichocnemis diff erent from Ergates ("genre très distinct"), and included both in the tribe "Aegosomites" and subtribe "Callipogonines." Lameere (1904) assigned Ergates to "Callipogonines," and divided it into three subgenera: E. (Ergates); E. (Trichocnemis); and E. (Callergates) Lameere, 1904. Ergates (Callergates) is currently considered a diff erent genus (Jeniš 2001(Jeniš , 2008. Casey (1912) again considered Ergates and Trichocnemis as distinct taxa, stating: "Th is genus is distinct from Ergates and should be restored. Th e last joint of the maxillary palpi in Ergates is oval and more narrowly truncate at apex, while in Trichocnemis it is of a wholly diff erent form, being broadly obtriangular, the sides straight and widely fl aring from base to the truncate apex. In the former there is a prominent lateral spiniform tooth at basal third of the prothorax, wanting in the latter, and there are numerous other incongruities. Th e two genera are related tribally but are unquestionably distinct." While this diagnosis points out many of the diff erences between the two genera, several other characters previously mentioned (i.e. antennal length and ratios) were omitted. In addition, Casey (op. cit.) did not indicate a tribal assignment for either of these genera. Nevertheless, taken as a whole, the characters enumerated by Casey (1890Casey ( , 1912 indicate substantial diff erences between Ergates and Trichocnemis. Nishio (1956) pointed out that "the three species of Ergates strongly diff er from each other in their morphology" and followed Lameere (1904) in maintaining each species in a diff erent subgenus. Nishio (op. cit.) also compared the male genitalia of the three species, and stated (translated): "Th e male genitalia of gaillardoti and spiculatus are similar to each other and probably suggest that they are closely related…". In addition, Nishio (op. cit.) hypothesized the phylogenetic relationship among the three taxa, stating that Callergates gailardoti is the most ancestral species of "Ergates," Trichocnemis spiculatus is sister to it, and Ergates faber is the most derived species. Moreover, Nishio (op. cit.) cites Plavilstshikov (1936) as stating that "spiculatus" differs from the remaining species (E. faber and C. gaillardoti) and should be classifi ed in a diff erent genus. Linsley (1962) synonymyzed Trichocnemis under Ergates, and assigned it to the tribe Ergatini, stating: "I agree with LeConte and Horn that the characters do not warrant the generic recognition of Trichocnemis and that the phylogenetic unity of the group is better indicated by including all four species in Ergates". In placing Ergates in the tribe Ergatini, Linsley (op. cit.) apparently ignored the name "Callipogonitae" used by Th omson (1861), and gave "Ergatites," used by Fairmaire (1864), priority over the names that appear in Lameere (1904Lameere ( , 1912Lameere ( , 1919: "Callipogonines"; Callipogonini. Th ere seems little doubt that Linsley was aware of the name "Callipogonides" in Lacordaire (1869), and probably incorrectly attributed this taxon to him. Th is would explain why Lisnley (op.cit.) did not use Th omson's name for Ergates and Callipogon in the same tribe: "Th is tribe is represented in America by two genera, Callipogon and Ergates". Th erefore, to Linsley, Callipogonini was equal to Ergatini, and not a diff erent group as considered formerly and by some contemporary authors.
In his work on the Cerambycidae of France, Villiers (1978) considered the three subgenera erected by Lameere (1904) as distinct genera, stating: "Trichocnemis J. Le-Conte et Callergates Lameere no sont pas des sous-genres d'Ergates, mais des genres bien individualisés". Villiers (op. cit.), used the tribal name Ergatini, although in a diff erent sense from that employed by Linsley (op. cit.); to him, Callipogonini sensu Lameere included more than one tribe, while Linsley (op. cit.) used Ergatini only as a name with priority over Callipogonini.
Th e revalidation of Trichocnemis by Villiers (op.cit.) as a separate genus remained unnoticed by many contemporary authors possibly because it was published as a part of a regional faunal account. Nevertheless, subsequent checklists of Western Hemisphere Cerambycidae (Chemsak andLinsley 1982, Monné andGiesbert 1994) unintentionally maintained the synonymy of Trichocnemis with Ergates.
Although the tribal classifi cation of Ergates and Callipogon Audinet-Serville, 1832, is beyond the scope of this paper, it is interesting to note Švácha (1987): "I would like to point out that it is undoubtedly incorrect to classify the genera Ergates and Callipogon in the same tribe, whatever its name may be." Unfortunately, Švácha did not enumerate the characters he used to base his opinion. Today, researchers of the Neotropical and Nearctic cerambycid fauna use Callipogonini sensu Lameere (1904), while those that work with the fauna of Palearctic, Ethiopian, Oriental, and Australian zoogeographic provinces (with some exceptions), do not agree and use more than one tribe to allocate the genera included by Lameere in Callipogonini.
A partial bibliography of Trichocnemis is listed below, including many citations of the generic name Ergates which actually refer to Trichocnemis (Monné 2006 Redescription. Body large, elongate, integument light brown to dark-brown; in general, elytra lighter than the head and the pronotum. Male (Figs 1,3, 5-7). Head proportionally small; coronal suture clearly surpasses the posterior edge of the eyes; dorsal surface coarsely punctate; pilosity short and scattered. Area behind the eyes confl uent punctate; pilosity short and clearly more abundant than in dorsal surface of the head. Antennal tubercles moderately prominent; apex rounded. Eyes small, not as long as scape in lateral view, and lower lobe narrower than scape at its widest point; dorsal interocular space equal or just narrower than twice the width of one upper eye lobe. Hypostomal area depressed to slightly depressed, rugose-punctate. Mandibles shorter than half of the length of the head, strongly curved inwards at almost straight angle; outer surface slightly tumid at basal one-third; inner margin not tumid and not strongly separated by the punctate area. Antennae short, just attaining the apical one-third of the elytra. Scape attaining to just surpassing the posterior edge of the eye lobe. Antennomere III moderately thick, with prominent denticles on ventral and lateral surface; longer than IV-V together. Genal apex spiniform. Maxillary palps short; palpomere II longer than the others; apex of the IV securiform or barely wider than base. Prothorax strongly tumid, entirely micropunctate. Pronotum with two large, deep and subtriangular antero-medial depressions; three punctiform, small, shallow to moderate, lateral antero-medial depressions, arranged diagonally; fi ve punctiform, small, shallow to moderate depressions, at basal area; lateral margins with spines clearly present, longer at anterior and posterior angles; lateral angles rounded; pilosity very short, very scattered (disc almost glabrous), longer and more dense laterally or close to the posterior and anterior angles. Prosternum with short and very scattered pilosity. Prosternal process wide; apex rounded; lateral margins and apical one-third with long dense pilosity. Meso-, metasternum, and metepisternum densely pilose. Elytra rugose-punctate, circum-scutellar area mostly punctate; each elytron with at least two clear carinae; sutural apex with short spine or inermis. Coxae abundantly pilose. Femora with short pilosity, becoming more dense ventrally, mainly at meso-and metafemora; profemora slightly rugose. Protibiae moderately short and thick. Protarsomere I short and wide. Urosternites pilose, mainly laterally. Parameres (lateral lobes) of the tegmen elongated, clearly narrowed, thickened, and carinate at apical half (subcylindrical).
Female (Figs 2, 4, 8). Diff ering from male in the following manner: antennae reaching or just surpassing middle of the elytra; scape shorter, just attaining the posterior edge of the eyes; antennomere III thinner, lacking denticles; curvature inwards at apex of the mandible at an obtuse angle; prothorax much less tumid; pronotum rugoso-punctate, strongly convex; with callosities in place of the depressions of the antero-medial and basal areas found in males, and without depressions at lateral of the antero-medial areas; lateral margins with larger and more spines (usually, the spines are bifi d or trifi d at apex); lateral angles clearly acute; posterior angles rounded; proepisterna coarse punctate; proepimera nearly fl at; profemora laterally fl attened.
Diagnosis. Trichocnemis diff ers from Ergates (Figs 9, 10) in the following manner: head proportionally small (0.6 times greatest width of pronotum in males); mandibles not strongly tumid at basal one-third of the outer surface; inner margin of the mandible not tumid and weakly separated by a punctate furrow; antennae of males do not reach the elytral apex; scape of the males reaches or surpasses the posterior edge of the eyes; antennomere III in males clearly thicker, with denticles, longer than IV and V together; antennomere III in females longer than IV and V together, attaining or almost attaining the base of the prothorax; pronotum distinctly tumid, mainly laterally, with deep and well marked depressions at disc; proepisternum, proepimerum, and prosternum (mainly close to the head) strongly tumid; lateral margins of the pronotum with at least some spines in both sexes; anterior angles of pronotum spinose in both sexes; lateral angle of the pronotum of the males not marked; profemora of males slightly rugose; elytra rugoso-punctate, with clear carinae; protibiae of males moderately short and thick; protarsomere I short and wide in both sexes; parameres of the tegmen elongated, clearly narrowed, thickened, and carinate at apical half.
In Ergates, the head is proportionally large (0.6 times greatest width of pronotum in males); mandibles strongly tumid at basal one-third of the outer surface, mainly in males; inner margin of the mandible tumid and strongly separated by a punctate furrow; antennae of males attain or surpass the elytral apex; scape of males not attaining posterior edge of eyes; antennomere III of the males clearly thinner, without denticles, and as long as IV-V together; antennomere III of the females does not attain the base of the prothorax, as long as IV-V together; pronotum not tumid, with callosities in place of the punctate depressions found in Trichocnemis; proepisternum and proepimerum not tumid; prosternum not tumid near head; lateral margins of the pronotum crenulated in both sexes; anterior angles of the pronotum wide and rounded in both sexes; lateral angle of the pronotum with prominent spines in both sexes (lateral angles acute in males); profemora of males strongly rugose; elytra coarse and densely punctate, with feeble carinae; protibiae of the males long and narrow; protarsomere I long and narrow in both sexes; parameres of the tegmen short, not narrowed after middle, somewhat concave, thickened only at outer lateral and apical one-third.
Trichocnemis diff ers from Callergates (Figs 11, 12) as follows: eyes not large; prothorax with distinct lateral declivities; genitalia of male shorter, with apex of the parameres of the tegmen thickened at apical half, and the median lobe enlarged at base and distinctly convergent to the apex. In Callergates the eyes are large, the prothorax lacks lateral declivities, the genitalia of the male is longer, with the apex of the parameres of the tegmen not thickened at apical half, and the median lobe is distinct narrower at base and slightly convergent to the apex. Additionally, the protibia in males are similar to Ergates.

Conclusions
Our analysis of these taxa, which corroborates that of Villiers (1978) and in part, those of Lameere (1904) and Nishio (1956), supports recognizing Trichocnemis and Ergates as distinct genera. Additionally, the fact that both species of North American Trichocnemis share several distinct characters not present in Ergates or Callergates further supports this hypothesis.

Synonyms of Trichocnemis spiculatus LeConte, 1851
White (1853) described two species from North America (California) that were later synonymyzed with T. spiculatus by Lameere (1904): Macrotoma californica and M. spiculigera. White's original description leaves some doubt as to the identity of the species involved. For example, in the description of M. spiculigera, he stated: "Elytra coriaceous, vermiculated, with three indistinct costae". Similarly, some details of the description of M. californica might encompass that of T. pauper. Since White probably did not examine the types of these species (frequently he indicated when he did), and his original descriptions do not provide enough detail to diagnose them among other Trichocnemis, primarily T. pauper, we examined photos of the types, provided by S. Shute (BMNH). Th e syntype male of Macrotoma californica (Figs 6, 8) and the holotype female of M. spiculigera (Fig. 8), are in fact M. spiculatus, as suspected by even White (op.cit.) himself: "Trichocnemis spiculatus, Leconte, Journ. Acad. Nat. Sc. Phil. n. s. ii 110?", and "It is possible that this may be the female of the Macrotoma Californica". Photos of the holotype (Fig. 8) also clearly show three distinct carinae on each elytron, rather than three on the elytra. According to S. Shute (personal communication) the types have the following labels: Macrotoma californica: Syntype 1 (Fig. 6)