Bisaltes (Bisaltes) tibialis ( Schaeffer, 1908 ) Santos-Silva & Wappes, 2021

Santos-Silva, Antonio & Wappes, James E., 2021, On the transference of Ataxia tibialis Schaeffer to Bisaltes (Bisaltes) Thomson with synonymies and new records in the genus (Coleoptera: Cerambycidae), Insecta Mundi 2021 (844), pp. 1-10 : 2-6

Bisaltes (Bisaltes) tibialis ( Schaeffer, 1908) , new combination

( Fig. 1–7 , 9–14 )

Ataxia tibialis Schaeffer 1908: 348 ; Aurivillius 1922: 292 (cat.); Linsley and Martin 1933: 183 (distr.); Breuning 1961: 47 (rev.); Linsley and Chemsak, 1985: 132; Hovore et al. 1987: 312; Chemsak et al. 1992: 117 (cat.); Monné 1994b: 72 (cat.); Monné and Giesbert 1994: 208 (checklist); Linsley and Chemsak, 1997: 348 (hosts); García Morales et al. 2014: 110 (distr.); Heffern et al. 2018: 748 (host); Monné 2020: 911 (cat.).

Description. Female ( Fig. 1–7 ). Integument reddish-brown to dark brown; palpi orangish-brown; gulamentum reddish-brown posteriorly, gradually dark brown toward anterior margin; scape and pedicel dark brown; antennomeres III–XI reddish-brown with dark brown apex (reddish-brown and dark brown areas lighter toward distal segments); antennomere XII reddish-brown. Pronotum dark brown. Elytra dark brown with irregular dark reddish-brown areas interspersed.

Head. Frons finely, sparsely punctate; with yellowish-brown pubescence partially obscuring integument, except yellowish-white pubescent band close to eyes; with long, erect, sparse brownish setae interspersed. Vertex and area behind eyes with sculpturing as on frons; with yellowish-brown pubescence nearly obscuring integument, with a few long, erect yellowish-brown setae interspersed. Antennal tubercles with sculpturing and pubescence as on frons. Wide central area of postclypeus with pubescence as on frons close to it, sparser toward anteclypeus; sides glabrous; with one long, erect dark seta on each side of wide central area. Labrum finely punctate, coplanar with anteclypeus at posterior quarter, finely punctate (punctures slightly coarser than on coplanar area), oblique on remaining surface (posterior margin of oblique area arched); with yellowish-brown pubescence not obscuring integument, with long, erect, both dark and yellowish-brown setae interspersed and directed forward. Genae as long as 0.45 times length of lower eye lobes; finely, sparsely punctate, except apex smooth; with yellowish-brown pubescence obscuring integument, except apex glabrous. Gulamentum smooth, glabrous on wide posterior area, depressed, striated-punctate, with short, bristly, pale yellowish-brown pubescence not obscuring integument anteriorly. Distance between upper eye lobes 0.56 times length of scape (0.37 times distance between outer margins of eyes); in frontal view, distance between lower eye lobes 0.88 times length of scape (0.58 times distance between outer margins of eyes). Antennae 1.45 times elytral length, reaching elytral apex at basal third of antennomere X. Scape with yellowish-brown pubescence nearly obscuring integument. Pedicel and antennomere III with yellowish-white pubescence nearly obscuring integument; antennomeres IV, VI, VIII, and X with dense yellowish-white pubescence on anterior 4/5, yellowish-brown on dorsal posterior fifth, almost glabrous on ventral posterior fifth; antennomeres V, VII, and IX with dense yellowish-white pubescence basally (this area longer ventrally), dense, yellowish-brown on remaining surface; antennomere XI with dense yellowishwhite pubescence, slightly sparser on apex; antennomere XII with yellowish-white pubescence not obscuring integument; antennomeres III–V with long, erect, sparse yellowish setae ventrally, and a few long, erect dark setae ventrally on apex; antennomeres VI–IX with a few long, erect dark setae ventrally on apex. Antennal formula (ratio) based on length of antennomere III: scape = 1.19; pedicel = 0.19; IV = 1.33; V = 1.14; VI = 1.09; VII = 0.90; VIII = 0.86; IX = 0.81; X = 0.71; XI = 0.59; XII = 0.17.

Thorax. Prothorax transverse, lateral tubercles conical, large, placed in middle. Pronotum convex, except in flattened well-marked posterior constriction; finely, sparsely punctate; with dense yellowish-brown pubescence, except each side with narrow, oblique yellowish-white pubescent band, from posterior margin to lateral tubercle of prothorax, wide, arched yellowish-white pubescent band on each side of central area, which are fused anteriorly and posteriorly following to margins, with glabrous, narrow, longitudinal central area from just before middle to posterior constriction. Sides of prothorax finely, sparsely punctate; with dense yellowish-brown pubescence, except narrow yellowish-white pubescent band close to pronotum, from anterior margin to lateral tubercle of the prothorax (following oblique band on sides of pronotum). Prosternum coarsely, sparsely punctate; with yellowish-brown pubescence centrally partially obscuring integument, denser laterally. Prosternal process with dense yellowish-white pubescence, and yellowish-brown pubescence interspersed; narrowest area 0.45 times width of procoxal cavity. Ventral surface of mesothorax with yellowish-brown pubescence, not obscuring integument on center of mesoventrite, denser on remaining surface (with yellowish-white pubescence on base and apex of mesanepisternum). Mesoventral process slightly narrower than mesocoxal cavity; abruptly elevated anteriorly. Metanepisternum with dense yellowish-white pubescence on anterior half, dense yellowish-brown pubescence on posterior half. Metaventrite with dense yellowish-brown pubescence. Scutellum with yellowish-brown pubescence partially obscuring integument. Elytra. Coarsely, sparsely punctate, punctures more distinct basally; apex obliquely truncate; with dense white pubescence on anterior third, with yellowish-brown pubescence interspersed, with posterior margin of this area obliquely narrowed and following toward posterior third along suture as wide band; posterior quarter with irregular white pubescent maculae; remaining surface with dense yellowishbrown pubescence, and distinct white pubescence maculae interspersed; with long, erect dark setae throughout.

Legs. Femora with yellowish-white pubescence basally, yellowish-brown on remaining surface, both partially obscuring integument. Tibiae with both yellowish-white and yellowish-brown pubescence interspersed, partially obscuring integument; metatibiae ( Fig. 6 ) slightly arched, not distinctly widened.

Abdomen. Ventrites I–IV with dense yellowish-brown pubescence, with yellowish-white pubescence centrally, especially on posterior half; ventrite V with dense yellowish-white pubescence, and yellowish-brown pubescence interspersed on anterior half.

Male ( Fig. 9–14 ). Differs from female by the metatibiae strongly widened ( Fig. 12 ).

Dimensions in mm (1 female, 2 males). Total length, 8.50/9.10–9.60; prothoracic length, 1.45/1.60–1.75; anterior prothoracic width, 1.55/1.65–1.85; posterior prothoracic width, 1.60/1.70–1.95; widest prothoracic width, 1.95/2.20–2.30; humeral width, 2.30/2.50–2.75; elytral length, 6.25/6.55–7.00.

Material examined. UNITED STATES OF AMERICA, TEXAS: Cameron Co., Sabal Palm Grove , 1 male, 26.V.1979, J.E. Wappes col. ( ACMT) ; 1 male, 5.VI.1982, J.E. Wappes col. ( MZSP) ; Starr Co., Salineño, Rio Grande River trail, 26°31′N / 99°07′W, 100′, beating Spiny Hackberry , 1 female, 08.IV.2018, J.E. Wappes col. ( ACMT) .

Remarks. Schaeffer (1908) pointed out in the description of Ataxia tibialis : “This interesting species is placed provisionally in Ataxia . It belongs evidently to Lacordaire’s Ataxiides and seems to be more related to Ataxia than to the other genera placed by him in this tribe or admitted there later by Bates.” Linsley and Martin (1933) reported that it “is not a typical Ataxia .” Breuning (1961) reported that he knew the species only by the original description. Linsley and Chemsak (1985) indicated they knew the holotype and two additional specimens, both from Brownsville. However, they did not report the sex of the two additional specimens. According to Hovore et al. (1987), “We know of only seven specimens, all from the palm grove; some specimens were collected from dead Zanthoxylum , some by miscellaneous beating and some at lights.” Again, the sex of the specimens was not reported, but the specimen figured by them was a male. Heffern et al. (2018) reported that they saw a female but did not describe it.

Based on this study it is clear that Ataxia tibialis belongs to Bisaltes Thomson, 1868 , currently in Apomecynini , and not to Ataxia , which is currently placed in Pteropliini . Linsley and Chemsak (1985) separated these two tribes in their key as follows: “3(2). Antennal scape with a distinct cicatrix at apex (feeble in some Ataxia ),” leading to Ataxiini (currently, equal to Pteropliini ); and “Antennal scape without a cicatrix at apex,” leading to Apomecynini . The separation between Pteropliini and Apomecynini is questionable. Nonetheless, as A. tibialis belongs to Bisaltes , it is an Apomecynini .

Thomson (1868) described Bisaltes and included three species: B. buquetii Thomson, 1868 ; B. posticalis Thomson, 1868 (= B. pulvereus ( Bates, 1866)) ; and B. acutipennis Thomson, 1868 (now placed in Ataxia , Apomecynini ). The inclusion of a species of Ataxia made the original description of Bisaltes inaccurate. Aurivillius (1900) described Craspedocerus, and Breuning (1942) considered it as a subgenus of Bisaltes . According to Breuning (1971) (translated): “Antennomeres III-V not enlarged… Bisaltes (Bisaltes) / these articles enlarged… Bisaltes (Craspedocerus) .” Using this definition, again Ataxia tibialis belongs to Bisaltes (Bisaltes) . According to Breuning (1971) on Bisaltes (translated): “Very elongated, cylindrical. Antennae moderately slender; scape moderately long, slightly wide, with open apical cicatrix. Antennal tubercles distant from each other. Eyes coarsely faceted, strongly emarginate. Pronotum transverse, convex, with lateral spine. Elytra very elongated, convex, slightly wider than pronotum. Head retractile. Prosternal process arched. Mesoventral process more or less truncate posteriorly. Metaventrite with normal length. Mesocoxal cavities closed laterally. Legs short, femora claviform, mesotibiae sulcate, metatibiae often enlarged and flattened in males. Entirely with erect setae.” This description agrees very well with the species currently placed in Bisaltes as well as with Ataxia tibialis .

Although it has never been reported, the antennae in some species of Bisaltes (Bisaltes) are 12-segmented (antennomere XII very small, but very distinct). Bisaltes (Bisaltes) tibialis also has the antennae 12-segmented ( Fig. 7 ).

Bisaltes (Bisaltes) tibialis is similar to B. (B.) uniformis , but differs by the upper eye lobes more widely separated in both sexes ( Fig. 1 , 9 ) (narrower in B. (B.) uniformis ( Fig. 8 , 15 )), white pubescent area on elytra more distinct in both sexes (less well-defined in B. (B.) uniformis ( Fig. 8 , 15 )), and abdominal ventrite V in male about as long as IV ( Fig. 10 ) (distinctly longer than IV in B. (B.) uniformis ( Fig. 16 )). It is also similar to B. (B.) bimaculatus Aurivillius, 1904 ( Fig. 23–26 ), but differs by the absence of a dark macula on each side of abdominal ventrite I, and metanepisternum not dark.

Figures

Figures 1–8. Bisaltes spp. 1–7) Bisaltes (Bisaltes) tibialis (Schaeffer), female. 1) Dorsal habitus. 2) Ventral habitus. 3) Lateral habitus. 4) Head, frontal view. 5) Mesocoxal cavity. 6) Metatibia. 7) Antennomeres XI–XII. 8) Bisaltes (Bisaltes) uniformis Breuning, female, dorsal habitus.

Figures 9–16. Bisaltes spp. 9–14) Bisaltes (Bisaltes) tibialis, male. 9) Dorsal habitus. 10) Ventral habitus. 11) Lateral habitus. 12) Metatibia. 13) Head, frontal view. 14) Mesocoxal cavity. 15–16) Bisaltes (Bisaltes) uniformis, male. 15) Dorsal habitus. 16) Ventral habitus.

Figures 17–26. Bisaltes spp. 17–18) Bisaltes (Bisaltes) uniformis, female, elytral apex. 17) Specimen 1. 18) Specimen 2. 19) Bisaltes obliquatus Breuning, holotype, dorsal habitus (by Jesus Santiago Moure). 20) Bisaltes uniformis, holotype, dorsal habitus (by Jesus Santiago Moure). 21) Bisaltes posticalis Thomson, 1868, holotype, dorsal habitus (by Jesus Santiago Moure).22) Esthlogena pulverea Bates, 1866, holotype, dorsal habitus (by Jesus Santiago Moure). 23) Bisaltes bimaculatus Aurivillius, holotype, dorsal habitus (by Jesus Santiago Moure). 24–26) Bisaltes (Bisaltes) bimaculatus, male from Brazil (Rio de Janeiro). 24) Dorsal habitus. 25) Ventral habitus. 26) Lateral habitus.