Oulema taophiloides, Gómez-Zurita, Jesús, 2011

Gómez-Zurita, Jesús, 2011, A new species of Criocerinae (Chrysomelidae) from New Caledonia: Oulema (Oulema) taophiloides sp. nov., Zootaxa 2870, pp. 63-68 : 64-68

Oulema (s. str.) taophiloides sp. nov.

Holotype (male): Nouvelle-Calédonie, Province Nord, Buahio river, 9.3km E Koumac Centre, 1.9km WNW summit of Bwe-Cian 20º32.912’S 164º20.954’E 58m, 19 December 2003, K.A. Johanson leg. (IBE-JGZ, Barcelona). Paratypes: three females, same data as male holotype (one paratype at IBE-JGZ, Barcelona; two at Naturhistoriska riksmuseet, Stockholm).

Habitus ( Fig. 1). Body elongated, with pronotum narrower than elytra, moderately convex. Length: 2.94 mm (holotype), 2.94–3.17 mm (paratypes); width: 1.25 mm (holotype), 1.31–1.38 mm (paratypes). Head, pronotum and claws dark brown, almost black, with slight bronzy reflection; five basal antennomeres, legs, elytra and abdominal segments orange-brown; apical antennomeres, mandibles, palpi, narrow basal border of pronotum, scutellum, postscutellar area on elytra, preapical patch on femora, and thoracic ventrites infuscate.

Head ( Fig. 2). Frons convex, glossy, relatively densely covered by minute shallow punctures, with sparse larger setigerous punctures anteriorly, bearing long scattered silvery setae; vertex with short longitudinal median impression; apex of anterior frontal groove with wide obtuse angle between eyes. Supraantennal calli lancetshaped, their tips convergent and with X-groove formed by frontal suture and basal tip of clypeus; surface glabrous, glossy, with few shallow punctures; triangular area between frontal suture and basal border of supraantennal calli, densely microreticulate and with dense long silvery pubescence. Eyes large, with oval perimeter and coarsely faceted; appearing as slightly protruding laterally after temples abruptly truncated posteriorly to frontal groove. Genae as long as half eye length, slightly expanded laterally to broadly rounded apical angles; anterior border of clypeus deflexed, weakly emarginated; clypeus outline as equilateral triangle between antennae, strongly expanded laterally below antennal sockets at apical half; sides concave and posteriorly converging in slightly depressed area with contiguous vertices of supraantennal calli and frontal angle; clypeus glossy, covered by setigerous punctures bearing long silvery, anteriorly recumbent setae. Labrum nearly as long as genae, broadly rounded at angles, almost completely covering mandibles. Antennae ( Fig. 3 ) reaching basal quarter of elytra, relatively stout; scape short, slightly longer than wide, inserted sublaterally at prebasal area into antennal socket, basally round, apex truncate and feebly swollen externally; second segment as long but narrower than first, anterior face constricted at base; third segment longer than second, with regular more slender profile; fourth and fifth segments progressively longer; sixth and seventh as long as fifth, but progressively broader; segments 8–10 nearly cylindrical, slightly narrower basally, with narrowly pedunculated base, subequal, shorter than seventh; apical segment longer than previous, with bluntly acuminate apex; four basal segments and fifth basally very finely microreticulated, sparsely covered by translucent setae; fifth segment and beyond granulated and more densely setose.

Prothorax ( Fig. 4 ). Pronotum convex, slightly longer (0.80 mm) than wide at maximal width (0.77 mm between anterior angles); surface glossy, shiny, with three types of puncturation: (i) minute shallow dense punctures like those on frons, evenly distributed, (ii) large round deep punctures sparsely and evenly scattered laterally on anterior half of disc, and in irregular longitudinal double series of about eight large punctures at midline; (iii) dense medium-sized punctures on transversally depressed area at basal third of pronotum; anterior border weakly convex and finely margined; anterior angles directed laterally, weakly protruding, with large setigerous pore at corner; sides weakly sinuous, slightly convex at apical ¾ and weakly concave at narrowed basal ¼; basal border slightly convex, narrowly margined medially, margination thickening towards posterior angles, with inner row of punctures; large setigerous pore at posterior angles. Hypomeron nearly unpunctured anteriorly, with dense medium-sized punctures basally. Prosternum smooth, anteriorly convex, unpunctured, except for premarginal row of setigerous punctures and punctures around coxae bearing long whitish setae. Procoxae nearly contiguous, cavities closed posteriorly.

Pterothorax. Scutellum sloping upwards posteriorly; trapezoidal, with base twice as wide as weakly emarginated truncated apex with blunt posterior angles; disc weakly concave, with very fine short hairs basally. Surface of elytra raised above that of pronotum; elytra at humeri 1.84x wider than pronotum at base; humeri broadly rounded, slightly protruding, concealing elytral margin as seen from above; sides subparallel before evenly rounded apical third; apices of elytra individually round, junction at suture obtusely angled; elytral surface slightly depressed longitudinally externally behind humeri, and transversely on disc towards suture in posthumeral region; surface glabrous, glossy, with numerous large round punctures, fossette-like on disc basally, slightly longitudinally elongated at lateral declivity; punctures regularly arranged in ten longitudinal rows, except slightly confused in postscutellar area and disc; longitudinal row of smaller, spaced punctures medially along first interval; postscutellar row of 4–5 smaller punctures present; sutural margin fine, weakly raised; space between ninth row and elytral margin feebly raised as longitudinal costa, hiding in dorsal view deflexed elytral margin along entire length except preapically; premarginal row of small punctures below lateral costa. Epipleura thin. Intercoxal process of mesoventrite subtrapezoidal, apex truncate, margined, covered with sparse punctures with long whitish pubescence. Wings fully developed. Mesanepisternum and mesepimeron densely covered by long recumbent whitish setae. Metaventrite smooth, finely longitudinally impressed at anterior half, with punctures denser and stronger towards sides, bearing long recumbent whitish setae; lateral and anterior borders relatively thickly margined, with adjacent series of punctures; apex of anterior intercoxal process broadly convex; posterior margin between metacoxae obtusely angular, with short median longitudinal notch.

Legs. Femora slightly enlarged medially, unarmed, sparsely covered by whitish recumbent pubescence. Tibiae straight, covered by semierect short pubescence; apices of tibiae internally with 1–2 peg-like, very small dark spines. Tarsi slender; first and second segments subequal, third segment slightly widened in meso- and metatarsi; third segment shorter than second, deeply bilobed nearly to base; fourth segment very small, but not concealed; last tarsal segment nearly as long as first and second segments together, curved, slightly widened towards apex; claws long, connate and fused at basal third, sharp, slightly emarginate apically at inner margin.

Abdomen. Abdominal segments convex, smooth, with sparse even small punctures bearing long posteriorly recumbent whitish setae, denser at sides; anterior border of first segment margined, with relatively long intercoxal process narrowing towards rounded apex fitting apical angular emargination of metaventrite; apex of last abdominal ventrite rounded in both sexes. Pygidium with single median dorsal stridulatory file close to base, slightly transversely elliptical.

Reproductive organs. Penis thick, nearly cylindrical, in lateral view straight at basal 2/3, bent at curved angle at apical 1/3, with sides more or less parallel ( Fig. 5 ); apex with sides regularly curved towards oval tip ( Fig. 6 ); edge of median orifice parallel to edge of penis; dorsal flap of orifice with median thin plate, slightly widened apically, flanked by lobe-like lateral plates. Spermatheca ( Fig. 7 ) hook-shaped, with basal part slightly longer than perpendicularly bent apical section; distal end weakly curved, with blunt pointed apex; basal part slightly widened towards proximal end; duct rather thick at insertion on basolateral end of spermatheca, narrowing as long and thin curled conduit, thickened again at proximal end of duct; insertion of spermathecal gland prebasally on thickened basal part of spermatheca, opposite to duct insertion.

Derivatio nominis. The size, coloration and general appearance of this species is reminiscent of several species of the eumolpine beetle genus Taophila Heller, 1916 , endemic from New Caledonia.

Differential diagnosis. Given their geographical proximity to New Caledonia, Australo-papuan Oulema are a priori the most meaningful choice for comparison with O. taophiloides sp. nov. Oulema medioplagiata ( Jacoby, 1898) from North Queensland is a larger (4–5 mm), differently colored species with an almost reversed color pattern compared to O. taophiloides , i.e. pronotum mostly pale and blackish antennae, legs, ventral surfaces and elytra, the latter with yellowish discal markings. This Australian species has shorter antennae and weakly raised intervals apically on elytra, nearly even in O. taophiloides (except for premarginal costa). In turn, O. diminuta Gressitt, 1965 from northern New Guinea, while similar in size (2.8–3.5 mm) to O. taophiloides , also has an inverted color pattern compared to the latter having darker elytra and paler head and pronotum. Puncture arrangement on the elytra is more regular in this species than in O. taophiloides and intervals are raised as costae posteriorly, which are more or less flat in O. taophiloides . The penis of O. diminuta has a broad, roundish dorsal flap basally on median orifice, which is thin and elongated in O. taophiloides .

Taxonomic remarks. Montrouzier's taxonomy is known to be problematic, even when it comes to suprageneric (e.g. subfamily) assignments. The irreplaceable loss of this author's primary types makes it impossible sometimes to assess his taxonomic decisions. Given this uncertainty, it is important to confirm that the new taxon described here is not the same as one of his Lema , particularly those not critically evaluated by Fauvel (1907) or Heinze (1930). Lema bletiae was considered a synonym of S. javeti by Fauvel (1907), but not so by Heinze's (1930) early review of Stethopachys . Lema bletiae is a large beetle (7.5 mm long), twice as big as O. taophiloides , with smooth pronotum and colored differently than the species of Oulema described here; its coloration is indeed suggestive of S. javeti , particularly by the infuscate premarginal area at apical half of elytra. Lema bipustulata from the island of Lifou (Loyalty Islands) has the same size—3.0 mm—as O. taophiloides , but their coloration differs strikingly: the head and pronotum of L. bipustulata were described as pale, with a darkened bordure in the latter, and elytra as brown with two pale yellowish spots on disc, whereas in O. taophiloides , head and pronotum are entirely dark, and the elytra are uniformly brown. It seems thus clear that the species newly described here has not been identified by previous authors working on New Caledonian fauna.

Biology. We have no information about the biology of this species. The other New Caledonian Criocerinae , Stethopachys javeti , lives on orchids (pers. obs.), as it is common for species of this genus also in Australia and New Guinea ( Hawkeswood 2009). But considering that most, if not all Eurasian Oulema feed on grasses ( Poaceae ) ( Wellso and Hoxie 1988), it is predictable that this species will be also associated with gramineous plants.

Figures

FIGURES 3 – 7. Oulema taophiloides sp. nov. Fig. 3, antenna; Fig. 4, pronotum, dorsal view; Fig. 5, penis, lateral view; Fig. 6, apex of penis, dorsal view; Fig. 7, different shapes of spermathecae.