Trachyphloeosoma newthayorum Borovec and Anderson, 2024

Borovec, Roman & Anderson, Robert, 2024, Two new Trachyphloeini (Coleoptera; Curculionidae; Entiminae) from Laos, Zootaxa 5506 (1), pp. 145-150 : 148-150

Trachyphloeosoma newthayorum Borovec and Anderson n. sp.

urn:lsid:zoobank.org:act:526FF0FB-4831-4E0D-B1FB-7D9F91A05AA4

( Figs 3, 4 , 9–13 )

Type material. Holotype: ♂, Laos, Bolikhamxai Province, Nakai-Nam Theun NBCA (N end), ca 2 km SW Kaew Nua Pass , 690-710 m, 18°22.292 N, 105°09.152 E, 5.vi.2008, hardwood and bamboo forest w/tree ferns, FMHD2008 - 029, berlese, litter incl. bamboo and under flowers of Mesua ferrea ( Clusiaceae ), A. Newton & M. Thayer, ANMT site 1227 ( FMNH). Paratypes: 6 specimens, same data as holotype (2 CMNC, 3 FMNH, 1 RBSC).

Body length: holotype 2.09 mm, paratypes 2.09–2.61 mm. Body ( Figs 3, 4 ) dark brownish, antennal funicles with clubs and tarsi slightly paler. Entire body except for antennae and tarsi covered with encrustation not allowing examination of appressed scales. Each elytral interstria with one dense and conspicuous row of erect piliform setae, slightly shorter than width of interstria; distance between two setae almost twice as long as length of one seta. Pronotum with similar setae, only slightly shorter than elytral ones, densely scattered. Head with rostrum with similar setae, slightly shorter than those on pronotum. Antennal scapes, femora and tibiae with short, erect piliform setae.

Rostrum ( Figs 9, 10 ) short and wide, 1.06–1.11× as wide as long, widest at base, slightly evenly tapering apicad with straight sides, at base 1.09–1.14× as wide as at apex, apically broadly rounded; in lateral view regularly vaulted, in apical portion declined. Epifrons widest at base, distinctly tapering anteriad with straight sides, dorsally with indistinct median longitudinal furrow. Epistome not developed; fronto-epistomal area short and wide, glabrous, smooth, posteriorly contrastive separated from squamosa epifrons.Antennal scrobes in dorsal view visible as narrow furrows throughout entire length, in apical portion narrowly reniform; in lateral view conspicuously enlarged posteriad, with dorsal margin directed towards dorsal margin of eye, then curved downwards and reaching ventral margin of eye; ventral margin directed downwards and almost reaching ventral margin of rostrum. Eyes small, in dorsal view faintly prominent outline of head; in lateral view oval, placed above middle of head hight, its diameter smaller than width of scape at apex. Head coarsely punctate behind eyes.

Antennal scapes slender, faintly exceeding anterior margin of pronotum in repose, 4.5 × as long as wide at apex, weakly evenly enlarging apicad, at apex 0.6–0.7× as wide as club, curved at midlength. Funicle of 7 antennomeres; antennomere 1 1.9–2.1× as long as wide and 1.7–1.8× as long as antennomere 2, this is 1.5–1.6× as long as wide; antennomeres 3 and 4 isodiametric; antennomere 5 1.1× as wide as long; antennomere 6 1.2–1.3× as wide as long; antennomere 7 1.4–1.5× as wide as long; clubs 1.5–1.6× as long as wide.

Pronotum ( Figs 3, 4 ) as wide as long to 1.07× as wide as long, widest at anterior third, constricted behind anterior margin; anterior margin narrower than posterior one. Disc roughly, densely irregularly punctured with space between punctures conspicuously shorter than their diameter. Pronotum in lateral view regularly domed. Anterior margin bent strongly back beneath and towards coxae.

Scutellum not visible.

Elytra ( Figs 3, 4 ) oval, 1.32–1.38× as long as wide, widest slightly before midlength, with regularly rounded sides, apically narrowly rounded. Striae densely coarsely punctured, interstriae flat, slightly wider than puncture diameter, somewhat smooth. Elytra in lateral view regularly vaulted.

Femora edentate. Protibiae somewhat slender, 5.15–5.34× as long as at middle wide, in apical quarter distinctly curved inside and here asquamose and densely covered with short appressed setae, apically subtruncated with dense fringe of short yellowish setae; all tibiae with long conspicuous mucro. Tarsi short; tarsomere 2 1.2–1.3× as wide as long; tarsomere 3 1.3–1.4× as wide as long and 1.3–1.4× as wide as tarsomere 2; onychium 0.8–0.9× as long as tarsomere 3; claws long, free, distinctly divaricate.

Abdominal ventrites 1.09–1.15× as long as wide, roughly punctured, space between punctures slightly longer than their diameter; ventrite 1 at middle 1.5× as long as ventrite 2; ventrite 2 slightly longer than ventrites 3 and 4 together; ventrite 5 in males apically concave. Suture between ventrites 1 and 2 sinuose, the other straight. Metaventral process narrower than transverse diameter of metacoxa.

Penis ( Fig. 11 ) 2.3× as long as wide, in dorsal view subparallel-sided, apical portion subtriangular with slightly concave sides, tip narrow, apically shortly obtuse; in lateral view narrow, in middle part almost straight, tip curved inside, evenly pointed. Temones twice as long as body of penis. Sternite IX with spiculum gastrale anteriorly curved, narrowed, posteriorly with basal arms fused, slender.

Spermatheca ( Fig. 12 ) with slender and regularly curved cornu; corpus large, elongated; ramus not developed; collum very small, hump-shaped. Sternite VIII with long and slender apodeme, Y-shaped and terminating in basal part of plate; plate small, subtriangular with slender fenestra reaching middle of plate. Gonocoxites slender and long, in apical portion tube-shaped, with laterally directed apical styli.

Etymology. This species is named after the collectors of the type series, Al Newton and Margaret Thayer, Field Museum of Natural History (retired) by combining the first syllable of each of their surnames with the suffix ‘orum’.

Biology. All known specimens were sifted from forest floor litter in a middle elevation mountainous area along the Laos-Vietnam border, with extensive, moderately disturbed hardwood (tropical montane) forest on moderate slopes, with bamboo and tree ferns common in the understory. This forest area is very extensive and runs along the border for tens of kilometers in both directions.

Differential diagnosis. Trachyphloeosoma newthayorum has a funicle with 7 antennomeres, all elytral interstriae with a conspicuous row of long erect setae only slightly longer than setae on pronotum, rostrum long, slender and pronotum widest at anterior third. In these characters it is similar to T. jirka Ren, Borovec & Zhang known from China and Vietnam and T. lirenae Borovec known from Vietnam. Trachyphloeosoma newthayorum can be distinguished from both species by small eyes, in lateral view with diameter smaller than width of scape at apex (eyes mid-sized with diameter slightly longer than width of scape at apex in both other species) and ventrite 5 in males apically concave (ventrite 5 in males apically obtuse in both other species). It also differs from T. jirka by a long funicular antennomere 2 (1.1–1.2× as long as wide in T. jirka ), penis with tip more elongate and wider in dorsal view, slender at middle and straight in lateral view (tip shorter and very narrow in dorsal view and wide and regularly curved in lateral view in T. jirka ) and female sternite VIII with plate short with fenestra (plate long and slender lacking fenestra in T. jirka ). It also differs from T. lirenae by the head behind eyes punctured (finely longitudinally striate in T. lirenae ) and penis with elongate tip (not so in T. lirenae ). In its elytra with dense, long erect setae Trachyphloeosoma newthayorum is similar also to T. ales Borovec & Anderson, 2022 described from Taiwan, but it is easily distinguished by a long series of characters: pronotum widest at anterior third and regularly domed on disc (widest at midlength, with wide longitudinal median furrow in T. ales ), head behind eyes punctate (finely striate in T. ales ), abdominal ventrites sparsely punctate (densely punctate in T. ales ), penis with elongate tip (apically broadly rounded in T. ales ), spermatheca with small, hump-shaped collum (corpus lacking collum, apically constricted and then regularly rounded in T. ales ) and female sternite VIII with fenestra (lacking fenestra in T. ales ).

Figures

FIGURES 1–4. Dorsal and lateral habitus. 1–2. Laohajekia uniformis. 3–4. Trachyphloeosoma newthayorum.

FIGURES 5–13. Structural details. 5–8. Laohajekia uniformis. 5. Head and rostrum, dorsal view. 6. Head and rostrum, lateral view. 7. Penis, dorsal and lateral view. 8. Spermatheca. 9–13. Trachyphloeosoma newthayorum. 9. Head and rostrum, dorsal view. 10. Head and rostrum, lateral view. 11. Penis, dorsal and lateral view. 12. Spermatheca. 13. Sternite VIII in female. Scale bars: 0.50 mm (5, 6, 9, 10, 13), 0.25 mm (7, 11) and 0.125 mm (8, 12).