Caledomus extraordinarius, Kirejtshuk & Kovalev, 2017

Kirejtshuk, Alexander G. & Kovalev, Alexey V., 2017, Caledomus gen. nov., a new cillaeine genus (Coleoptera, Nitidulidae) from New Caledonia and taxonomic notes, Zootaxa 4277 (3), pp. 443-450 : 446-448

Caledomus extraordinarius sp. nov.

( Figs. 1–11 )

Type specimens. Holotype, male ( BMNH) and 9 paratypes ( BMNH, ZIN)—“ In base Bromeliad leaves ”, “N. New Caledonia, Tinchialit, 2,020 ft, 21.ix-3.x.1949, L.E. Cheesman, B.M. 1950-1”.

Description of holotype (male). Length with mandibles 7.1, width 3.6, height 0.6 mm. Elongate, subflattened dorsally and ventrally; subunicolorous yellowish reddish (subochraceous) with median infuscation along middle of tergites uncovered by elytra; body with a faint shine; head behind eyes with very fine hairs and some places on thoracic sclerites covered with sparse and subrecumbent nearly inconspicuous hairs, although posterior part of hypomeron and abdominal sclerites with short and slightly conspicuous golden yellowish hairs, shorter than distance between insertions; elytra with short golden yellowish hairs associated with fine punctures on elevated intervals between furrows.

Head and pronotum with punctures somewhat larger than eye facets becoming coarser at head base and pronotal sides (at posterior pronotal angles with diameter up to twice as great as eye facets), interspaces between punctures finely alutaceous. Elytra with regular longitudinal furrows containing coarse subcontiguous punctures (puncture diameter about 2–3× as great as eye facets), intervals between furrows smoothed to alutaceous with one longitudinal row of very fine punctures separated by 3–5 puncture diameters. Thoracic sterna with more or less obsolete punctation and mostly finely alutaceous to smooth, but prosternal process and median part of mesoventrite with very sparse and medium-sized punctures, metaventrite with somewhat coarser punctures. Abdominal sclerites diffusely, indistinctly punctured to microtuberculate, densely and finely microreticulate.

Head transverse (markedly shorter than distance between eyes) and moderately narrowing behind extremely finely faceted eyes, slightly convex at base and flattened anteriorly, its anterior margin shallowly emarginate and unbordered. Labrum subtrapezoid and slightly narrowing anteriorly, transverse and with distinct median suture, truncate in the middle and arcuate at lateral angles. Mandibles with tridentate apices with rather small subapical teeth. Antenna about as long as head width, scape longer than wide and somewhat curved, antennomere 3 about 1.5× as long as antennomere 2, other flagellomeres shorter, elongate oval club about fourth of total antennal length, nearly 1.5× as long as wide, antennomere 9 slightly shorter than antennomeres 10 and 11 combined, antennomere 11 shortest and subtruncate at apex. Pronotum bordered along sides and at anterior and posterior angles, widest at middle and gently narrowing anteriorly and posteriorly. Scutellar shield about 1.5× as wide as long. Elytra flattened at disc and with extremely narrowly explanate sides, apical outer angle widely rounded. Tergite 6 slightly longer than tergite 5 and tergite 7 almost 1.5× as long as tergite 5.

Mentum rather large and transverse, about 2.5× as wide as long, bisinuate at anterior margin and with widely rounded anterior and distinct posterior angles. Terminal labial palpomere about twice as long as wide. Terminal maxillary palpomere about 1.5× as long as wide. Antennal grooves arcuate and reaching level of posterior end of curved part of temples. Apex of prosternal process twice as wide as its narrowest part. The distance between mesocoxae 1.5× and that between metacoxae nearly as great as that between procoxae. Metaventrite flattened, about as long as prosternum with process. Abdominal ventrite 1 about twice as long as ventrite 2, each of ventrites 3 and 4 1.5–2.0× as long as ventrite 1, ventrite 5 longest and about 4× as long as ventrite 2 and with median triangular depression with reduced pubescence along whole length.

Tibiae somewhat wider than antennal club, slightly curved; protibia somewhat curved and rounded at its apical outer angle; meso- and metatibiae with distinct outer subapical angle; spurs very small and rather stout. Profemur more than 1.5× as wide as corresponding tibia, meso- and metafemora less than 1.5× as wide as corresponding tibiae.

Protarsus somewhat wider than antennal club, meso- and metatarsi somewhat narrower (not more than 1.5× as wide as corresponding tibiae), claws simple and narrow.

Aedeagus as in Figs. 8–9 .

Female. Differs from the male in the shorter terminal abdominal segment (hypopygidium about 3× as long as ventrite 2), pygidium widely rounded to subtruncate at apex, hypopygidium subtruncate at apex and only with weak depression with reduced pubescence, and also somewhat narrower tarsi. Ovipositor as in Fig. 10 , moderately sclerotized, gonocoxites about one-fourth total length of ovipositor.

Variations. Length with mandibles 6.7 – 8.3 mm. The body coloration is more or less stable in the type series, although the tergal median infuscations vary somewhat in the paratypes; a certain variability is observable in punctation and sculpture of integument. The body of different paratypes is with long and fine inconspicuous hairs located in various places, and this circumstance makes it possible to suppose that these specimens were initially covered with such hairs uniformly spread along the head and thoracic sclerites.

Biology. Bionomy of this new species remains unknown, although the labels pinned under the specimens of the type series suggest association of this species with interstices of living plants, including at base of leaves. The capture of the type specimens “ in base Bromeliad leaves ” seems to be evidence of the habit of this species, but not of specialization on a peculiar food plant since the plant family Bromeliaceae has its natural range in the Western Hemisphere, although members have been introduced elsewhere by man. Therefore, the capture of these specimens in the introduced plant can be used as evidence of peculiarities of the beetle’s mode of life but probably not of their food selectivity.

Figures

FIGURES 1 – 6. Caledomus extraordinarius gen. et sp. nov. (“ N. New Caledonia, Tinchialit, 2,020 ft, 21. ix- 3. x. 1949, L. E. Cheesman, B. M. 1950 - 1 ”), male, holotype, BMNH (Figs. 1, 3 – 5); female, paratype, ZIN (Figs. 2, 6). 1: body, dorsal, male; 2: body, dorsal, female; 3: head, ventral; 4: thorax, ventral; 5: male abdomen, ventral; 6: female abdominal apex, ventral. Scale bars = 1.0 mm.

FIGURES 7 – 11. Caledomus extraordinarius gen. et sp. nov. (“ N. New Caledonia, Tinchialit, 2,020 ft, 21. ix- 3. x. 1949, L. E. Cheesman, B. M. 1950 - 1 ”), male, holotype, BMNH (Figs. 7, 9); female, paratype, ZIN (Figs. 10, 11). 7: male anal sclerite and spiculum gastrale, ventral; 8: tegmen, ventral; 9: penis trunk, dorsal; 10: ovipositor, ventral; 11: spiculum ventrale, ventral. Scale bars = 0.5 mm: a, for Figs. 7 – 10; b, for Fig. 11.