Archellerenius, Wanat, Marek, 2013

Wanat, Marek, 2013, The Apionidae (Coleoptera: Curculionoidea) of New Caledonia. Genera Archellerenius gen. nov. and Hellerenius Wanat, Zootaxa 3717 (4), pp. 515-542 : 517

Genus Archellerenius gen. nov.

Type species: Archellerenius giustoi n. sp.

Diagnosis. The new, monotypic genus is closely related to Hellerenius, based on the shared shape of rostrum, head and elytra, isodiametric scutellum, arrangement of elytral striae and sensory setae, femora devoid of pseudotrochanter, general structure of male endophallus and presence of internal lamina in the female rectum. It is distinct from Hellerenius primarily in having the rostrum short and not differentiated sexually, smaller body size, polished elytra, well retained radial window of the wing, unmodified last abdominal ventrite, and much different structure of the ovipositor. It resembles the species of Zimmius Wanat, from which it can be distinguished by thinner rostrum devoid of extended and emarginate expansion of mesorostrum, legs with no trace of pseudotrochanter and with more robust true trochanters, elytra more regularly oval in dorsal outline, with complete striae, and the endophallus bearing a terminal, simply membranous extension. The superficially similar Caledonapion Wanat is clearly distinct in its short and stout rostrum, coarsely punctured ventrally, and thin legs with a pseudotrochanter.

Description. Body length about 3.0 mm. Integument black, glabrous, not shagreened, devoid of scale-like microsculpture. Rostrum not distinctly sexually dimorphic, straight, only slightly (1.1–1.2×) longer than pronotum, narrowed at base of prorostrum, the latter with vestigial ventral sulci in distal half; subgenal and latero-ventral sulci absent; scrobes entering head venter, their septum shallowly foveate; labrum with only lateral setae. Mouthparts as in Hellerenius ( Fig. 3 ). Head subisodiametric; frons gently elevated; vertex impunctate; head underside with completely irregular wrinkles near eyes; subocular setae absent. Antennae shorter than in Hellerenius, not clearly pseudogeniculate; scape at most 2× as long as mesorostrum breadth; at least two terminal funicular segments isodiametric; club compact, 2.0–2.5× as long as broad, 0.8–0.9× as long as scape. Pronotum slightly elongate, with obsolete subapical constriction; disc with subbasal line at most finely traced; posterior lateral groove shallow, with minute spur at upper end; prosternum extremely short. Scutellum minute, isodiametric. Elytra oval, finely microreticulate, shiny, without extended caudal part, in profile regularly convex; humeral calli prominent; no trace of basal rim; striae narrow and weakly impressed, arrangement of inner striae apically indistinct and often irregular, outer striae finely punctured, narrow throughout; intervals all flat; sensory setae 2–3 in row on 9th interval. Wing with radial window large and distinct; anal vein complex with 1A retained as paired rudiments, 2A without spur, 3A largely reduced ( Fig. 21 ). Mesoventrite distinctly angled in profile; mesepimeral sulcus narrow, sharply edged, impunctate. Metaventrite in middle ca. 1.5× longer than mesocoxa; rim of mesocoxae narrow but complete and well raised; intercoxal process elevated. Legs moderately long, unmodified in both sexes; femora weakly inflated, without pseudotrochanter, their bases and trochanters relatively robust; metafemur not exceeding elytral apex; tibiae straight, parallelsided, with extended and indistinct apical tuft of setae ( Fig. 20 ); tarsi slender; claws with short, blunt teeth ( Fig. 17 ). Membrane between tergites VII and VIII with pouch-like process in both sexes.

Male: Last abdominal ventrite (V) simply convex, unmodified. Pouch-like process of tergite VII membrane small, triangular, at base 4–5 × narrower than tergite VIII. Pygidium of exposed aspidapionine type, with distinct marginal rim. Sternite VIII short and shallowly emarginate, Sternite IX with transverse apical plate. Tegmen fused, with distinctly forked basal piece; tegminal plate deeply notched, membranous lobes present; suprafenestral sclerites and postfenestral plate both short; macrochaetae short and fine; fenestrae enlarged, well margined; prostegium long, bifurcate. Penis with shortly dichotomous apodemes; tectum rod-like throughout; pedon asymmetrical; endophallus as in Hellerenius with long, simply membranous terminal process sharply separated from microspinulose remainder.

Female. Antennal insertion as in male. Fifth abdominal ventrite flattened, its laterosternites united to form narrow apical flange ( Fig. 22 ). Tergite VII regularly rounded. Tergite VIII narrowly but fully divided to hemitergites. Pouch-like process of tergite VII membrane very large, at base almost as broad as tergite VIII. Ovipositor short, with markedly divergent gonocoxites bearing stout, hemispherical styli. Spermathecal duct short, equally wide throughout. Rectum with thin ribbon-like internal lamina as in Hellerenius ( Fig. 29 ).

Biology. Rainforest species; host plants unknown.

Distribution. New Caledonia (main island).

Etymology. The stem arche- of the proposed new name is derived from the Greek adjective archaios (in Latin archeos)—old, ancient, combined with the name of the closely related genus Hellerenius, to underline the more plesiotypic set of characters.

Figures

FIGURES 1 – 8. Mouthparts and rostrum underside, SEM photographs: 1) Hellerenius monteithi, male mouthparts; 2) H. plumipes, male mouthparts (arrow points on U-shaped stripes on outer side of terminal maxillary palp segment); 3) Archellerenius giustoi, female mouthparts; 4) H. plumipes, sensilla on apex of female maxillary palp, magnification 9600 ×; 5) H. monteithi, female prorostrum, ventral view; 6) H. plumipes, male rostrum, ventral view; 7) H. tibialis, female prorostrum, ventral view; 8) H. plumipes, female prorostrum, ventral view. Abbreviations: ls, mixed setae of labial ligula and maxillary malae; m, mandible; mp, maxillary palp (2 - segmented); pf, palpifer; po, postmentum; pr, prementum; sg, subgenal sulcus.

FIGURES 21 – 32. Archellerenius giustoi, male (23 – 26), female (21, 22, 27 – 32): 21) metathoracic wing, enlarged radial cell to show distinct radial window (21 A); 22) apical flange of last abdominal ventrite, postero-lateral view; 23, 24) pygidium in dorsal (23) and lateral (24) view; 25 – 28) abdomina in ventral (25, 27) and lateral (26, 28) view (notice mite nymph attached to female 2 nd ventrite); 29) rectum; 30) tergite VII; 31) spermatheca and bursa copulatrix; 32) terminalia with enlarged ovipositor. Abbreviations: b, bursa; c, coxite, d, spermathecal duct, g, gonads; p, pygidium; rr, rectal ribbon-like internal lamina, s, spermatheca; st, stylus, sv, spiculum ventrale; w, radial window.

FIGURES 9 – 20. Archellerenius giustoi, male (13, 15), female (9 – 12, 14, 17 – 20): 9) habitus, lateral view; 10) apex of elytra, postero-lateral view; 11) pronotum and elytra, dorsal view; 12) pronotum, dorsal view; 13, 14) head with rostrum, dorsal view; 15, 16) head with rostrum, lateral view; 17) tarsal claws; 18) protarsus; 19) antenna; 20) fore femur (part) and tibia.