Eugamandus albipumilus Lingafelter, 2020

Lingafelter, Steven W., 2020, New genera, species, and records of Acanthocinini (Coleoptera: Cerambycidae: Lamiinae) from Hispaniola, Insecta Mundi 754, pp. 1-23 : 2-6

Eugamandus albipumilus Lingafelter , new species

( Fig. 1–3 )

Diagnosis. Structurally, both species of Hispaniolan Eugamandus ( E. albipumilus , new species and E. darlingtoni Fisher ) are very similar. Eugamandus albipumilus has a diffuse, white pronotal macula anterior to the scutellum ( Fig. 1 , 2a ). In some specimens, this macula is extended longitudinally to the anterior margin. The elytra have a pale elytral declivous region bordered anteriorly by one or two small, black, rounded or triangular maculae ( Fig. 1 , 2a, b ). The basal costal elytral ridges are weakly elevated and the area between them toward the suture is very weakly sloping and nearly flat ( Fig. 2b ). Most of the ventral sclerites are covered in evenly spaced punctures, each bearing a single, thickened, scale-like, white or off-white seta ( Fig. 2c, d ). Eugamandus darlingtoni (see Perkins et al. 2020) lacks a white pronotal macula anterior to the scutellum. The elytra of E. darlingtoni have a vaguely pale apex marked at its anterior declivous margin of each with a small, narrow, transverse, black macula. The basal costal elytral ridges are pronounced and rise abruptly at approximately 45° between the suture and outer humeral margin in E. darlingtoni . The ventral seta-bearing punctures are less distinct than in E. albipumilus .

Description. Length: 5.3–6.3 mm; width: 2.4–3.0 mm.

Head: Covered in vestiture of short, dense, ochre setae except for large, separate punctures on frons and lower vertex between upper eye lobes which each bear a single longer, scale-like, white seta. Punctures on upper vertex and occiput behind upper eye lobes smaller, denser, mostly contiguous and lacking long, white setae. Narrow median-frontal line mostly delineated. Antenna: Extending beyond middle of elytra, near apical declivity, most segments reddish-brown at base and apex, piceous at the middle third, giving mottled appearance. Covered with dense, appressed, semi-translucent to golden pubescence. Antennal scape approximately as long as third antennomere, constricted at base and weakly swollen at middle; barely extending beyond anterior margin of pronotum. Antennomeres 6–10 subequal in length to one another. Antennomere 11 tapering to subacute point and slightly longer than penultimate. Eye: lower eye lobe longer than gena below it; nearly 1.5 times height of upper eye lobe; lobes connected by 2–3 rows of ommatidia. Upper eye lobes separated by about two-thirds the length of scape. Mouthparts: frontoclypeal margin with fringe of long golden semi-translucent setae, most of which extend to base of labrum (setae on lateral margins much longer); clypeus with very short fringe of golden pubescence at base. Labrum with off-white pubescence at base, becoming longer, denser, and more golden toward apex. Mandibles with dense covering of appressed golden pubescence on outer margins.

Thorax: Pronotum reddish-brown, without dorsal or lateral tubercles; slightly broader than long; broader than head but narrower than elytral base. Moderately dense, appressed, ochre to golden setae covering the surface except for base anterior to scutellum and extending upward and outward into diffuse macula. Scattered, large, ovoid punctures present over much of pronotum, most of which bear a single, white, scale-like seta. Scutellum piceous, impunctate, broadly rounded posteriorly with dense, white, appressed setae on outer third, sometimes coalescing posteromedially, but with mostly glabrous middle third to anterior margin. Prosternum with sparse punctures and scattered off-white setae becoming denser and ochre toward sides. Prosternal process about 1/3 width of procoxa, broadly expanded at apex to about midpoint of each procoxa, closing procoxal cavities posteriorly. Mesosternum very short, distance between pro- and mesocoxae about the same as width of prosternal process between procoxae. Sparse punctures and scattered off-white setae becoming denser and ochre toward sides. Mesosternal process between mesocoxae approximately 1.5 times width of prosternal process. Metasternum covered with appressed, off-white or ochraceous pubescence, becoming denser at sides and on the lateral thoracic sclerites, but glabrous along middle sulcus. Scattered, large punctures present, each bearing a single off-white or ochre seta. One larger seta-bearing puncture on either side of middle sulcus posteriorly, just anterior to metacoxae. Elytra: slightly broader than pronotum at base. Each elytron averaging 4 mm in length and 1.3 mm in width at middle, covered with combination of appressed, golden, ochraceous, and off-white setae forming vague light to dark maculae or mottling. Large but broadly-spaced punctures over most of surface, each bearing a single, white, scale-like seta. Two or three costae elevated along the basal two-thirds. Apical third of elytra distinctly declivous, more lightly colored than remainder (except for small circular or triangular black macula near base of declivity), and narrowed to suture at apex. Three sets of gibbosities are present, best viewed from lateral perspective: one at base, one at middle, and one at apex of declivity of each elytron. Region between basal gibbosities toward suture weakly sloping. Epipleura not distinct. Legs: relatively short, mostly uniformly pubescent with ochraceous setae over most of surface, but with 2–3 vague, narrow annulae of darker setae on all tibiae and venter of meso- and metafemora. Tibiae slightly shorter than associated femora. Metafemora extending to approximately apical third of elytra. Tarsi paler reddish-brown than remainder of legs, with white to off-white setae along the distal margin of segments 1–3.

Abdomen: Piceous, shiny, generally darker than most integument elsewhere, especially dorsally. Ventrites with sparse, short, ochre and off-white setae, with exception of apex of fifth ventrite which has a fringe of long, fine, ochraceous setae. Large, widely spaced, seta-bearing punctures present throughout.

Distribution. Endemic to Hispaniola, this species is known only from the low montane and coastal lowland areas of the Dominican Republic ( Fig. 3 ).

Remarks. Eugamandus Fisher (1926) is superficially very similar to Nanilla Fleutiaux and Sallé (1889) , despite them being in separate tribes ( Eugamandus is in Acanthocinini while Nanilla is in Parmenini ). The type species of Nanilla , N. delauneyi Fleutiaux and Sallé (1889) , shares with the type species of Eugamandus , E. schwarzi Fisher (1926) , a similar antennal scape, elytral apical declivity, and overall form. Interestingly, Fisher did not make any comparison of Eugamandus to Nanilla when he described the genus, so it is possible that he did not consider it (perhaps because it was placed in a different tribe). Several species now placed in Nanilla and Eugamandus are clearly flightless with unproduced humeri and fused elytra and even more pronounced globose form (although the type species of each do not appear to be flightless). Further study needs to be made to clarify the differences and phylogenetic placement of these genera. Possibly a generic synonymy is necessary, along with creation of a new genus for the morphologically distinct, flightless forms that have been placed in each, but that is beyond the scope of this paper.

Eugamandus is here defined by the presence of fully developed flight wings, unfused elytra that are abruptly declivous at the apical third, humeri slightly, but distinctly projecting and not continuous with the pronotal margin, and overall more elongate and less globose proportions than Nanilla .

With the present description, eight species are known (all from the Greater Antilles) including two species now known from Hispaniola. Eugamandus darlingtoni Fisher , a montane species, was described from “the foothills of the Cordillera Central, south of Santiago”, an interior locality. The present species has been collected only in areas near the coast (mostly below 200 meters) in the Dominican Republic.

Etymology. Eugamandus Fisher is a masculine genus name and was formed by combining elements of the first and middle names of Eugene Amandus Schwarz, for whom it was patronymic. The masculine epithet, albipumilus , is attributed to the variably developed white pronotal macula (albi -, Latin, meaning “white”) and overall small size of the beetle (pumilus, Latin, meaning “dwarf”).

Type material. Holotype: Dominican Republic: Puerto Plata Province, Reserva Cientifica Isabel de Torres , 704 m, 23 June 2010, 19°45′55.6″N, 70°42′42.8″W, beating, S. W. Lingafelter (male, USNM) . Paratypes: all Dominican Republic: La Altagracia Province, Parque Nacional del Este, Boca de Yuma , 18°21.508′N, 68°36.956′W, 3–20 m, 28 June 2005, beating, S.W. Lingafelter ( USNM, 1) ; La Altagracia Province, Parque Nacional del Este, Boca de Yuma , 18°21.904′N, 68°37.094′W, 2 m, 5 August 1999, at light, M. A. Ivie & K. A. Guerrero ( WIBF, 1) ; La Altagracia Province, road to Hoyo Azul, 2.3 km S. Verón, 18°34.738′N, 68°26.628′W, 55 m, 2 December 2014, S.W. Lingafelter ( SWLC, 1) ; La Altagracia Province,

Punta Cana Reserve , 18°30′40″N, 68°26.628′W, 11–14 November 2005, screen sweep, L. Masner ( CMNH, 1); San Cristóbal Province, Borbón, Cuevas Pomier , tropical deciduous forest, Malaise trap, 28 July–5 August 1995, S. & J. Peck, Specimen # 95–46, 200 m ( CMNC, 1) ; Barahona Province, near Filipinas, Larimar Mine , 27 June 1992, beating, F. W. Skillman ( FWSC, 1) ; Azua Province, Sierra Martín García, 9 December 2014, 925 m, 18°21.224′N, 71°00.870′W, A. S. Konstantinov ( SWLC, 1) .

Figures

Figure 1. Eugamandus albipumilus Lingafelter, new species. Digital painting by Taina Litwak.

Figure 2. Eugamandus albipumilus Lingafelter, new species. a) Dorsal habitus, holotype male. b) Lateral, holotype. c) Closeup of sterna, paratype female.

Figure 3. Distribution map of Eugamandus species known from Hispaniola.