Arpactophilus xaracuu Breitkreuz, Ohl & Engel, 2016, sp. nov.
Creators: name: Breitkreuz, Laura C. V.
name: Ohl, Michael
name: Engel, Michael S.
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Crabronidae
Arpactophilus
Arpactophilus xaracuu

description: Arpactophilus xaracuu sp. nov.
(Figs. 107–108)
Diagnosis. Arpactophilus xaracuu is the only New Caledonian species in the genus that has an elongate, reddishblack mandible which extends to the opposite mandibular base when in repose. Other distinctive characters are the black labrum with six pointed teeth and the almost entirely black body (some specimens entirely black, some with partly reddish metasoma).
Description. FEMALE: Total length 9.7–11.5 mm, mean = 10.4 mm; forewing length 6.5–7.2 mm, mean = 6.9 mm.
Body black with areas of reddish black, brown, or red integument. Mandible dark reddish black apically. Most of tegula and tarsi brown. Some specimens with a partly red metasoma (basal segments) (Fig. 108). Wings infumate; pterostigma dark brown.
Head about 0.9 × as long as wide in frontal view. Apical margin of clypeus with three teeth; mid tooth distinctly shorter than lateral teeth; margin between mid and lateral teeth gently concave (Fig. 107). Apical margin of labrum with a deep medial V-shaped and two U-shaped incisions lateral to medial incision, with angles of incisions projecting and forming six pointed teeth (Fig. 107). Mandible elongate, apex of mandible extending to base of opposed mandible when in repose (Fig. 107); lower mandible tooth about 1/3 of total mandibular length. Palpal formula 4:4. Frons finely colliculate and slightly wrinkled with short and dense setae. Frontal carina present from median ocellus to apical margin of clypeus, elevated to a small point on lower frons, to small ridge on upper clypeus, and forming median tooth of apical margin of clypeus. Scape 5.4 × as long as wide. Ocellar triangle anterior of tangent between upper posterior orbits of compound eyes, lateral ocelli anterior of tangent by more than their diameter. Occipital carina interrupted dorsally (Fig. 6). Gena smooth, finely imbricate with sparse punctation and short setae, without tubercles, spines, or dorsoventral carina. Hypostomal midventral line carinate with bordering short transverse carinulae on hypostomal integument, not angulate.
Mesosoma about 1.7 × as long as wide in dorsal view. Propodeum about 0.8 × as long as wide in dorsal view. Mesosoma imbricate with dense punctation (Fig. 108), except on dorsal surface of propodeum; mesopleuron and lateral surface of propodeum also transversely carinulate; dorsal surface of propodeum coarsely reticulate with small longitudinal carina bending laterally towards apex (similar to pattern in Fig. 20, but finer). Deeply pitted sulcus present posterior to mesoscuto-mesoscutellar sulcus. Hypersternal sulcus a long, deep and slightly pitted groove. Metafemur 3.7 × as long as wide. Metatibia without differently colored area apically. Pretarsal claws without teeth. Forewing with two submarginal cells; anterior border of submarginal cell II much shorter than posterior border. Hind wing with six distal hamuli.
Metasoma matt, punctation basally more sparse than apically (Fig. 108). Metasomal sternum II swollen medially, forming bulge (as in Fig. 2). Pygidium with broad row of silk setae apically.
MALE: Unknown
Remarks. Arpactophilus xaracuu is easily identified by the black labrum with six pointed teeth (Fig. 107), its large size (it is the largest known species of New Caledonian Arpactophilus), and elongate mandible. Among other large species of Arpactophilus the labral form never approximates the form observed in A. xaracuu or an elongate mandible that extends to the opposing mandibular base when in repose is present (only approximated in A. webbi, but mandibles are yellow). One of the six specimens of A. xaracuu has the legs lighter in color (dark brown basally, light yellowish light brown apically) and an entirely black metasoma, without the red observed in the other specimens. Given that these color differences are known from only one specimen which otherwise has the same structural and sculpturing characters, it seems to be conspecific. Two specimens have a small inconspicuous yellow spot laterally on the clypeus. These specimens could be male, but the apex of the metasoma is missing in both and so gender association is not possible.
Material examined. HOLOTYPE ♀: “ NEW CALEDONIA 12038: 22°15’S x 166°49’E, 280m, Pic du Pin, site 1. 23 Dec 2004– 12 Jan 2005. Burwell, Wright. malaise, rainforest [QM].
PARATYPES 4♀, 2 sex indet.:
4♀: (1x) NEW CALEDONIA 8926: 21°11’S x 165°18’E, 850m, Aoupinie top camp. 23 Nov 2001 – 1 Feb 2002. Burwell, Monteith. Malaise [QM]; (1x) NEW CALEDONIA 12074: 22°19’S x 166°55’E, 480m, Foret Nord, site 1. 22 Dec 2004– 9 Jan 2005. Burwell, Wright. Malaise, rainforest [QM]; (1x) “Nouvelle Calédonie, Mont Koghis. 350m, 25.IV.1995, Réc. Chazeau & Jourdan [MNHN];
sex indet.: (1x) “Nouvelle Calédonie, Pinda 30m, 18.IV.1995, Réc. Chazeau & Jourdan [CAS]; (1x) “ NEW CALEDONIA, Mt. Khogis, 500m, 17km NNE Nouméa, 24–26 Dec. 1991, M.E. Irwin, D.W. Webb; Malaise trap across forest stream [UCDC].
Etymology. The specific epithet is taken from the name Xârâcùù, one of the New Caledonian native languages. It is treated as a noun in apposition.
description: Published as part of Breitkreuz, Laura C. V., Ohl, Michael & Engel, Michael S., 2016, A review of the New Caledonian Arpactophilus (Hymenoptera: Crabronidae), pp. 1-66 in Zootaxa 4063 (1) on pages 51-53, DOI: 10.11646/zootaxa.4063.1.1, http://zenodo.org/record/270412