Nesioeme apicalis Niisato, Vives & Heffern, 2020

Niisato, Tatsuya, Vives, Eduard & Heffern, Daniel, 2020, A new genus and species of the tribe Oemini (Coleoptera, Cerambycidae, Cerambycinae) from the Sundaic region, Southeastern Asia, Zootaxa 4755 (3), pp. 553-560 : 555-559

Nesioeme apicalis Niisato, Vives & Heffern , new species

( Figures 1‒27 )

Description. Male. Colour reddish brown, weakly shiny; mandibles reddish brown, with black apical third; antennae black, with reddish brown scape; elytra dull reddish brown, matted, provided with black band in apical third which is emarginate in wide V-shaped on anterior margin; legs reddish brown, black in tibiae and tarsomeres I and II, dull yellowish-brown in III and V, and partly black at bases of trochanters and apices of femora. Body densely clothed with light golden-yellow pubescence intermixed with long same coloured setae, the long setae are partly longer and wavy on head and pronotum, and becoming black on apical band of elytra; antennae densely clothed with dark brown pubescence intermixed with long, erect same coloured setae, except for brown pubescent scape.

Head slightly wider than apical width of pronotum, densely provided with small-sized punctures in somewhat irregular arrangement, with intervening areas of punctures densely micropunctate; frons little more than half of maximum width, with fine short median furrow; intervening area between frons and clypeus provided with a few large, coarse punctures near middle; vertex entirely flattened. Antennae slightly exceeding middle of elytra, densely, coarsely punctate, punctures fine on apical two antennomeres; scape very thick, gently arcuate, as long as III and V, slightly longer than IV; XI weakly dilated to apical third, bluntly pointed apicad.

Pronotum moderately wider than long, disc provided with a pair of weak, oblique swellings just before middle, weakly depressed on sides near apex, strongly depressed along basal margin; surface sparsely, somewhat irregularly provided with small-sized punctures, with intervening areas of punctures densely micropunctate. Scutellum semicircular.

Elytra little more than 2.5 times as long as humeral width; sides subquadrate at humeri, dilated in a weak sinuate line to apical 3/10, then arcuately narrowed to apices; disc depressed around suture behind scutellum and along each longitudinal area in external third near bases, densely, evenly provided with small punctures, the punctures getting shallower in about apical fourth.

Venter of thorax strongly rugose and provided with large coarse punctures on pro- and mesoventrite, and base of metanepisternum, rather sparsely with shallow punctures on otherwise; prosternum weakly emarginate laterally, deeply grooved along midline. Abdomen rather sparsely provided with small punctures.

Metafemora almost attaining apical fourth of elytra; metatarsomere I 2/3 length of following two combined.

Male genitalia ( Figs. 10–15 ): Median lobe relatively small, weakly convex, arcuate in lateral view; dorsal plate gently narrowed to apex with a straight line, bluntly rounded on apical margin, exposing apical part of ventral plate which is distinctly thickened; median struts relatively broad, 3/5 length of median lobe. Tegmen 4/5 length of median lobe; parameres widely separated from one another, with each lobe relatively short and broad, rounded simply at apex, provided with one very long and one medium setae at apex; ring part 3/5 length of tegmen. Tergite VIII semicircular, subtruncate on apical margin, densely clothed with medium to long straight setae. Sternite VIII transverse, weakly oblique on sides of apical margin which are clothed with medium straight setae. Endophallus not examined because it could not inflate due to damage near distal half.

Female. Colour almost as in male, slightly paler and shiny in general, reddish yellow in all tibiae and tarsi, lighter on femora and ventral surface except for sides of thorax which are moderately brownish, antennomere XI (and apex of X in paratype from Borneo) somewhat reddish.

Head as in male, not so voluminous. Antennae reaching basal 2/5 of elytra. Pronotum almost as in male though slightly varied in shape and structure depending on individuals, wider than long (holotype from Sumatra) or as wide as long (paratype from Borneo), with base as wide as apex (holotype) or wider than apex (paratype); disc weakly raised along midline and on arcuate areas laterally, the raised areas indistinctly divided into shallow concavities in an irregular arrangement (holotype) or hardly uneven (paratype). Scutellum rounded triangular. Abdomen with anal ventrite, slightly arcuate on wide apical margin.

Female genitalia ( Figs. 16–18 ): Ovipositor moderately long; baculi in coxite arcuate; baculi in paraproct sinuate, not reaching base of paraproct; coxite lobes large and semicircular, weakly sclerotized; styli weakly sclerotised, moderately dilated apicad. Spermatheca broad, moderately arcuate on external margin, straight on inner margin though bent ventrad near apical third, with elongate gland; duct relatively short, simply sinuate.

Measurements. Holotype female (Sumatra): BL 15.90 mm; HW/PA 1.09; HW/PW 0.74; PL/PW 0.78; PL/PA 1.17; PB/PA 1.00; EL/EW 2.53; EL/PL 4.04. Paratype male (Malay Peninsula): BL 14.30 mm; HW/PA 1.16; HW/ PW 0.75; PL/PW 0.82; PL/PA 1.27; PB/PA 1.18; EL/EW 2.60; EL/PL 3.75. Paratype female (Borneo): BL 11.76 mm; HW/PA 1.20; HW/PW 0.77; PL/PW 0.87; PL/PA 1.35; PB/PA 1.17; EL/EW 2.74; EL/PL 3.95.

Type series. Holotype: female ( MZBI), “ Aceh State ” “ Sumatra, Indonesia ” “ III. 2011 ” (typed on a white card) / “ HOLOTYPE ” “ Nesioeme ” “ apicalis ” “Niisato, Vives” “& Heffern, 2020” (typed on a red card with black margin). Paratypes: 1 male ( CLD), “W MALAYSIA ” “ PAHANG;” “ Benom Mts.; 3,53N 102,53N ” “” 15km E of Kampong Dong ;” “ 24.iii.–15.iv.1998; 300–1000m;” “Dembický & Pacholátko leg.” / “COLECTIO—L. DEMBICKÝ” “ CE- RAMBYCIDAE ” “Invt No.7223”; 1 female ( CDH), “ Malaysia, Sabah ” “ Tongod 500m ” “ III–18–2014 ” “local coll”.

Etymology. The specific name is derived from the black apical band on the elytra.

Distribution. Sumatra, Borneo and Malay Peninsula.

Notes. Compared to the two female specimens, from Sumatra (holotype) and Borneo (paratype), the male paratype from the Malay Peninsula has the body more robust and different colouration on the elytra and legs, more uneven disc of the pronotum, and weaker and sparser punctation on the pronotum and the elytra ( Figs. 19–24 ). It is uncertain whether these differences are due to the sexual dimorphism or geographical variation, but other basic features agree well with each other and there is no doubt they belong to the same species. It may be possible to distinguish them as local populations if we could examine additional specimens, particularly males from Sumatra or Borneo.

Figures

FIGURES 1–4. Habitus of Nesioeme apicalis Niisato, Vives & Heffern, new genus and new species: 1, 2, paratype male from Malay Peninsula; 3, holotype female from Sumatra; 4, paratype female from Borneo. 1, 3, 4, dorsal view; 2, ventral view.

FIGURES 5–9. Hind wing and mouth parts of Nesioeme apicalis Niisato, Vives & Heffern, new genus and new species, holotype female from Sumatra: 5, hind wing; 6, left mandible, dorsal view; 7, right mandible, dorsal view; 8, maxilla, ventral view; 9, labium, ventral view. Scales: 2.50 mm for fig. 5; 0.50 mm for figs. 6‒9.

FIGURES 10–18. Genitalia of Nesioeme apicalis Niisato, Vives & Heffern, new genus and new species: 10–15, paratype male from Malay Peninsula; 16–18, holotype female from Sumatra. 10, median lobe, dorsal view; 11, ditto, apical part, dorsal view; 12, ditto, lateral view; 13, tegmen, dorsal view; 14, ditto, lateral view; 15, abdominal segments VIII–IX; 16, abdominal segment IX (ovipositor), ventral view; 17, abdominal segment VIII, ventral view; 18, spermatheca with duct. Scales: 0.50 mm for figs. 10, 12, 13–15, 16, 17; 0.25 mm for figs. 11, 18.

FIGURES 19–24. Discal features on pronotum and elytra of Nesioeme apicalis Niisato, Vives & Heffern, new genus and new species: 19, 22, paratype male from Malay Peninsula; 20, 23, holotype female from Sumatra; 21, 24, paratype female from Borneo. 19–21, pronotum near middle; 22–24, elytron near base. Scale: 0.50 mm.

FIGURES 25–27. Tibia and claw of Nesioeme apicalis Niisato, Vives & Heffern, new genus and new species (SEM images): 25, paratype male from Malay Peninsula; 26, 27, holotype female from Sumatra. 25, 26, apical part of fore tibia; 27, hind claw. Scale: 500 μm for figs. 25, 26; 300 μm for fig. 27.