Ancistrotilla, Brothers, 2012

Brothers, Denis J., 2012, The new genus Ancistrotilla n. gen., with new species from Vanuatu and New Caledonia (Hymenoptera, Mutillidae), Zoosystema 34 (2), pp. 223-251 : 226-228

Genus Ancistrotilla n. gen.

TYPE SPECIES. — Ancistrotilla azurea n. sp.

ETYMOLOGY. — Latinised from Greek “ankistron”, hook, with reference to the shape of the parapenial lobes; the suffix - tilla is a common one in Mutillidae , derived from Mutilla .

DIAGNOSIS. — Male. Erect brachyplumose and plumose setae present; antennal scrobe with transverse carina dorsally and separate lamellate projection dorsolaterally; clypeus with pair of large acute forward-facing teeth medially on anterior/ventral margin; mandible apically bidentate; mentum convex, glossa short and blunt; notaulus absent; axilla with distinct flattened dorsal surface; marginal cell obtuse apically with spur-like vein or angle at posterolateral extremity; T1 with narrow pale integumental band posteriorly; both T2 and S2 with lateral felt line; hypopygium strongly bidentate medioapically; parapenial lobe well developed, medially curved and hook-like apically; penis valve with single strong apical tooth.

Female. Erect brachyplumose setae present; antennal scrobe with strong dorsal carina almost reaching eye; mandible apically bidentate; mentum convex, glossa short and blunt; metapleural-propodeal suture obliterated; T1 with narrow pale integumental band posteriorly; T2 apically without medially oriented pubescence, with short lateral felt line; pygidial plate delimited; hypopygium strongly bidentate medioapically.

DESCRIPTION

Male

Integument usually dark, sometimes with metallic reflections;T1 with narrow pale integumental band posteriorly. Erect setae brachyplumose, plumose behind eye at least.

Head. Broadly transverse, about as wide as mesosoma. Occipital carina distinct dorsally.Vertex convex. Eye transversely broadly ovate, strongly protruding, surface shining, ommatidia scarcely discernible. Ocelli small to moderate, closely spaced. Antennal tubercles slightly separated basally.Antennal scrobe deep, not reaching eye margin but defined laterally by a vertical ridge, with a short transverse flange or tooth dorsomesally (sometimes scarcely developed) and separate prominent lamella lateroventral to this. Clypeus deeply depressed dorsolateral to projecting flattened punctate median area, ventral margin convex with large acute projection on each side of midline. Malar space less than basal height of mandible. Genal carina absent. Hypostomal carina strong, lamellate, extending almost straight to posterior mandibular condyle. Proboscidial and mandibular fossae separated by depressed anteriorly unfused bridge, proboscidial fossa slightly longer than smooth postgenal bridge. Scape strongly bicarinate anteroventrally. Pedicel slightly wider than long, shorter than first flagellomere, which subequal to second flagellomere. Mandible in dorsal/anterior view evenly curved, weakly tapering, with strong longitudinal carina dorsally, bidentate apically, subapical tooth well developed, ventrally with strong basal tooth (sometimes scarcely developed). Maxillary palp 6-segmented; labial palp 4-segmented; intermediate palpomeres strongly flattened and broadened, densely covered with short apically bent erect setae on functionally ventral surface. Mentum smooth, longitudinally convex, posteromesally slightly swollen; glossa short and blunt.

Mesosoma. Surface densely punctate except smooth on metapleuron, and reticulate on propodeum. Pronotal dorsal face (excluding anterior collar) with anterior margin slightly convex, rounded, epaulet merely a tuft of fine erect setae, humeral angle rounded; posterodorsal margin broadly V-shaped. Tegula broadly ovate, not reaching median level of scuto-scutellar suture, convex but very weakly recurved posteriorly, almost entirely smooth and glabrous. Mesoscutum without notaulus, parapsis almost indistinguishable; posterolateral corner forming a slight flattish lobe discontinuous with axilla. Scutellum flattish; axilla posterolaterally concave, dorsal horizontal surface distinct. Metanotum simple, transverse. Propodeum evenly convex, disk and declivity merging in lateral view. Metasternal process broadly tridentate, apex blunt to strongly emarginate, shorter than metacoxal height.

Wings. Forewing with moderate ovate sclerotised pterostigma; marginal cell fairly short, broadly obtuse apically, often with distinct spurlike vein posteroapically; three closed submarginal cells.

Legs. Tibial spur formula 1-2-2. Mid- and hind tibiae without dorsal spines, apical spines not inserted on any process; apical spurs longitudinally concave dorsally, margins microserrate, densely clothed with microsetae.Metacoxa with distinct even longitudinal carina on inner margin; metatibia subapically with secretory pore near base of inner spur.

Metasoma. T1 slightly longer than wide, <0.5× width of T2, evenly expanded from base, convex, not constricted (but sometimes parallel-sided) apically; anterior auricle prominent, vertically lamellate.T2 densely punctate; lateral felt line narrow and long. T3-6 more finely punctate. T7 mostly punctate, apical pygidial area weakly sculptured (sometimes smooth). Sterna finely punctate. S1 with weak longitudinal carina. S 2 in lateral view strongly convex anteriorly; lateral felt line short. S7 partially exposed but apparently very short. Hypopygium about as long as wide, sparsely punctate, posterior margin with prominent acute tooth on each side near midline.

Genitalia. Paramere elongate, slender, laterally obliquely flattened and weakly twisted, acute apex weakly curved dorsad. Parapenial lobe well developed, apically bluntly hook-like and strongly curved mesad. Cuspis divided near base, paracuspis a short lobe, ventral lobe cylindrical; digitus elongated and laterally flattened, shorter than cuspis. Penis valve almost asetose, apically truncate with a strong long vertical hook-like tooth.

Female

Integument usually dark, sometimes with metallic reflections; T1 with narrow pale integumental band posteriorly. Erect setae inconspicuously brachyplumose.

Head. Broadly transverse, posterolateral angle rounded. Occipital carina present dorsally (sometimes inconspicuous).Eye broadly horizontally ovate, strongly protruding, surface shining, ommatidia scarcely discernible. Antennal scrobe broad, almost horizontal, with very strong flangelike transverse dorsal carina almost reaching eye. Clypeus with raised triangular punctate region above complete strong transverse carina, itself above depressed transverse smooth area. Malar space greater than basal height of mandible.Hypostomal carina strong, lamellate, extending almost straight to posterior mandibular condyle. Proboscidial and mandibular fossae separated by depressed anteriorly unfused bridge, proboscidial fossa scarcely longer than smooth postgenal bridge. Scape simple. Pedicel slightly longer than wide, shorter than first flagellomere; first flagellomere longer than wide, longer than second. Mandible slender, tapering, bidentate apically, with ventral basal tooth (sometimes scarcely evident). Maxillary palp 6-segmented; labial palp 4-segmented. Mentum smooth, evenly convex; glossa short and blunt.

Mesosoma. Longer than wide, broadened to point posterior to prothoracic spiracle, then narrowed to projecting propodeal spiracle, dorsum convex; propodeum rounded posteriorly, disk and declivity merging. Pronotal dorsal face (excluding anterior collar) with anterior margin slightly convex, rounded, epaulet tuberculate; posterodorsal margin indicated by crenulate broadly concave ridge (sometimes inconspicuous). Scutellar scale absent. Pronotalmesopleural suture entirely distinct. Mesopleuron almost smooth anteriorly and posteroventrally; vertical mesopleural ridge well developed, rounded and broad dorsally. Metapleuron mainly smooth and shining. Metapleural-propodeal suture entirely obliterated; endophragmal pit large and deep. Lateral face of propodeum mainly smooth and shining. Mesosternum with strong even median transverse carina anterior to mesocoxae. Metasternal process triangular, about as long as metacoxal height.

Legs. Tibial spur formula 1-2-2. Foreleg with tarsal comb. Mid- and hind tibiae each with two rows of prominent spines, few spines in each row, apical spines not inserted on any distinct process; each subapically with secretory pore near base of inner apical spur; apical spurs narrow, finely serrate laterally. Metacoxa with strong even longitudinal carina on inner margin.

Metasoma. T1 much wider than long, about half width of T2, evenly expanded from base, weakly convex, not constricted apically; anterior auricle prominent, vertically lamellate. T2 lateral felt line broad, less than ⁄₄ as long as T2 laterally. T6 with pygidial area sculptured and well defined by lateral carina ending posteriorly in a blunt angle (sometimes smooth and laterally undefined), posterior margin weakly concave laterally, convex medially.S2 strongly convex anteromedially, without felt line. S6 with apex deeply emarginate.

REMARKS

The males of this genus are particularly characteristic and easy to recognise, specially from the form of the antennal scrobe, the clypeus, the tegula, the axilla, T1 and the genitalia. The females, however, are less easily distinguished from other genera, and are most similar to Ephutomorpha sensu stricto (for which males are unknown and which, in addition to E. aurata , also includes E. chrysochlora (André, 1895) , E. interjecta (André, 1901) , E. pulchella (Smith, 1855) and E. rubromaculata (André, 1895) , at least); Ancistrotilla n. gen. females differ in having apparently larger eyes (relatively smaller and more distant from the posterior margin of the longer head in Ephutomorpha ), no trace of the metapleural-propodeal suture (forming a distinct ridge in Ephutomorpha ), strongly spinose meso- and metatibiae (dorsal spines far fewer and very small in Ephutomorpha ), the postero-medial pubescence on T2 posteriorly or weakly diagonally oriented (transverse in Ephutomorpha ), S2 simply convex (with a transverse groove at about ⅔ its length in Ephutomorpha ) and the pygidial plate broad and distinct (at most represented by a narrow smooth line almost concealed by pubescence in Ephutomorpha ). Unfortunately, we have no information on the biology of any of the species of Ancistrotilla n. gen., but the well-developed foretibial comb, strong dorsal spines on the meso- and metatibiae and distinct flattened pygidial plate of most females suggest that the hosts are usually ground-nesters.

Based on specimens authoritatively identified by comparison with the relevant types, I also include the following species in Ancistrotilla n. gen.: A. albocaudata (André, 1898) n. comb. from Mutilla (♂; type locality Australia, Queensland, Mackay), A. calcarina (André, 1898) n. comb., n. stat. from “var.” of Mutilla senilis André, 1898 (♂; type locality Australia, Queensland, Mackay), A. caledonica ( André, 1896) n. comb. from Mutilla ( Sphaerophthalma [sic]) (♀; type locality New Caledonia, Noumea), A. carbonaria (Smith, 1855) n. comb. from Mutilla (♂; type locality Australia, Tasmania), A. fabricii (André, 1898) n. comb. from Mutilla (♀; type locality Australia, Queensland, Mackay), A. senilis (André, 1898) n. comb. from Mutilla (♂; type locality Australia, Queensland, Mackay), A. transiens (André,1898) n. comb., n. stat. from “var.” of Mutilla senilis (♂; type locality Australia, Queensland, Mackay), A. transitoria (André, 1903) n. comb., n. stat. from “var.” of Ephutomorpha senilis (♂; type locality Australia, Queensland, Cairns, Kuranda) and A. viridiceps (André, 1895) n. comb. from Mutilla ( Sphaerophthalma [sic]) (♂; type locality Australia, Queensland, Mackay). In addition, I have seen specimens of several undescribed species from Australia and one from New Guinea. It is premature to attempt to provide a key to the species at this stage, since the necessary revisionary work has not been done, and the generic limits, specially for the females, are still somewhat unclear. Both new species with blue males described below are very similar to A. transitoria , a widespread blue eastern Australian species, but differ strikingly in their penis valves (with the apical tooth longer and entirely separated from the ventral lamellae in A. transitoria ). The third new species has penis valves similar to A. transitoria but is essentially black and with much less white pubescence on the metasoma.