Duocristala Lingafelter, 2020

Lingafelter, Steven W., 2020, New genera, species, and records of Acanthocinini (Coleoptera: Cerambycidae: Lamiinae) from Hispaniola, Insecta Mundi 754, pp. 1-23 : 12-14

Duocristala Lingafelter , new genus

( Fig. 7–9 )

Diagnosis. This genus is most easily recognized by the presence of two strongly erect pubescent tufts on each elytron ( Fig. 7a, d ): one at the centro-basal position and one medially ( Fig. 7d, e, f ). Other characters include the strongly clavate femora ( Fig. 8a, b ), medially swollen antennal scape ( Fig. 8a ), long interocular seta on frons at edge of lower eye lobe ( Fig. 7b ), broad pronotum with strong, broad lateral tubercles and large, separate punctures ( Fig. 7c ), elytra without erect hairs (except for tufts), without a lateral carina, and with rounded apices ( Fig. 7e ). Justification for proposing this new genus is presented in the Remarks, along with comparison to other genera of Acanthocinini .

Description. Length: 6.2–6.7 mm; width: 2.4–2.6 mm.

Head: Covered in vestiture of short, dense, appressed green and blue-green setae; mostly impunctate. Median-frontal line well delineated and complete from clypeus to occiput. Frons with single long seta emerging from brown spot at middle edge of each lower eye lobe. Antenna: Long, slender, extending beyond elytral apices by about 5 antennomeres. Antennomeres with short pubescence only, distinctly pale yellow annulate at basal fourth and dark brown at apical three-fourths of antennomeres 6–11. Antennal scape reaching to just beyond lateral pronotal tubercles; thickened at middle. Eye: lower eye lobe large, over 1.5 times taller than gena and about twice as long as upper eye lobe; lobes connected by 4–5 rows of ommatidia. Upper eye lobes widely separated by about greatest width of scape. Mouthparts: labrum, clypeus, and palpi very pale yellow; terminal maxillary palpomeres elongate and pointed at apex; mandibles reddish-brown at basal half, piceous at apical half.

Thorax: Pronotum covered in short, appressed pubescence; large, oval, mostly separate punctures concentrated around most of disk with greatest concentration along posterior half and behind lateral tubercles, but also extending around and above tubercles; center of pronotal disk with few punctures. Pronotal disk without tubercles dorsally except for swollen anterior margin; with single, broad, lateral tubercle at each side, posterolaterally positioned with acute apex. Scutellum moderately pubescent, broadly rounded posteriorly. Prosternal process greater than 1/2 width of procoxa at narrowest point, broadly expanded at apex to about midpoint of each procoxa, apex about equal to width of procoxa, closing procoxal cavities posteriorly. Mesosternal process between mesocoxae slightly broader than prosternal process and about 2/3 width of mesocoxa. Metasternum mostly impunctate with very shallow metasternal sulcus that terminates at anterior third. Elytra: each with pronounced mediobasal and medial pubescent tuft emerging from very slight integumental bulge, otherwise covered in dense, appressed, mottled pubescence and lacking erect setae. Large, separate punctures most prevalent on basal half, becoming sparse and inconspicuous on apical half. No distinct dorsal costae or lateral carinae present; epipleural region not abruptly delimited. Apices rounded to suture. Legs: femora strongly clavate and pedunculate; mesotibia with strongly developed antennal cleaning notch on dorsal edge at apical 2/3. Femora mostly covered in pale yellow, appressed pubescence; tibiae mostly covered in dark, appressed pubescence with a pale yellow annulus at middle. First metatarsus distinctly shorter than remaining tarsomeres together.

Abdomen: mostly impunctate and covered in fine, appressed, pale pubescence. Terminal ventrite slightly longer than penultimate in males; median basal carina lacking in males; unknown in females.

Etymology. Duocristala is formed from the Latin Duo, meaning two, crista, meaning crest or plume, and ala, meaning wing, and together the elements refer to the two prominent setal tufts on each elytron. The genus name is feminine.

Remarks. As discussed earlier, Monné (1990), provided a key to the genera of Neotropical Acanthocinini with a centro-basal setose crest. Using the key, the new genus would go to couplet 2 (as the antennae lack a dense tuft of setae, then couplet 4 as the metatibiae are cylindrical, then couplet 5 as each elytron has two setose tufts. Couplet 5 terminates in two genera, both of which are known only from South America: Trichalcidion Monné and Delfino which is distinguished by having the tufts protruding strongly without the integument projecting and Exalcidion Monné which has tufts emerging from integumental projections. Both of these taxa possess strongly spinose elytral apices and dorsally tuberculate pronota, unlike the rounded apices and relatively smooth pronotal disk in this new taxon. Because this taxon lacks an elytral carina, it is excluded from the genera treated in Monné (2001), although it shares with them the lack of erect elytral setae (excluding the tufts). Superficially, this taxon is similar to Leptocometes luneli (Chalumeau and Touroult) . Both share a centro-basal elytral crest, strongly clavate femora, and posteriorly positioned lateral pronotal tubercles. However, the absence of scattered, erect, elytral setae, presence of a pronounced medial elytral tuft, swollen antennal scape, and rounded elytral apices distinguish the new taxon. Therefore, given that no other genera have the suite of characters present in this taxon, and no genera of Acanthocinini with two elytral pubescent tufts are known from the Caribbean islands, the new genus, Duocristala is proposed.

Type species. Duocristala viridifrons Lingafelter , new species, by present designation.

Figures

Figure 7. Duocristala viridifrons Lingafelter, new genus, new species. a) Anterior view, holotype male. b) Head, paratype male. c) Pronotum, paratype male. d) Lateral view, holotype male. e) Dorsal elytron, paratype male. f) Closeup of medial elytral tuft, holotype male.

Figure 8. Duocristala viridifrons Lingafelter, new species. a) Dorsal, holotype male. b) Ventral, holotype male.

Figure 9. Distribution map of Duocristala viridifrons Lingafelter, new species, Leptostylopsis opuntiae Lingafelter, new species, and Lethes turnbowi Lingafelter, new species.