Aglaotilla chalcea Taylor, Murphy, Hitchen & Brothers, 2019

Taylor, Christopher K., Murphy, Mark V., Hitchen, Yvette & Brothers, Denis J., 2019, Four new species of Australian velvet ants (Hymenoptera: Mutillidae, Aglaotilla) reared from bee and wasp nests, with a review of Australian mutillid host records, Zootaxa 4609 (2), pp. 201-224 : 204-208

Aglaotilla chalcea Taylor, Murphy, Hitchen & Brothers , sp. nov.

Figs 1 –2.

Diagnosis. Females can be distinguished by the combination of a metallic purple coloration on both body and legs with a bronze-green gloss on the head, a median spot of white setae on the posterior margin of T2 without prominent spots on the other tergites, head not much extended behind eyes, T2 without prominent depressions, and antenna with F1 subequal to F2. Males are evenly metallic dark blue with a purple gloss, with predominantly black setae on the clypeus, head not much extended behind eyes, humeral angle distinct but not acute, tegula with produced lobe posteriorly (fig. 2c), and genitalia with large parameres bearing numerous elongate setae both externally and internally, including thick brush of setae internally.

Description. Female (fig. 1). Total length 5.08–9.37 mm; mesosoma length 1.71–3.11 mm. Integument dark metallic purple; head with strong bronze-green gloss, clypeus under antennal scrobe dull orange, mandible orange basally, black distally; mesosoma with weaker green gloss than head, appearing purple in most lights; legs (except black tarsi) and metasoma uniformly purple without green gloss; tibial spurs white. Head in frontal view subquadrate, 1.1 as wide as long; width of head behind eyes 0.9 width of mesosoma; head densely punctate. Occipital carina well developed, continuing onto postgenal carina. Sides of head behind eyes converging, posteromarginal corners of head distinct but rounded. Eye ovate, hemispherical, margins entire; maximum eye diameter 2.2 distance between top of eye and rear margin of head, minimum frons width 0.6 head width. Frons and vertex with white semi-decumbent, simple setae, and black erect, brachyplumose setae with very few barbs; white setae becoming denser, more erect, brachyplumose towards lower margin of frons and above occipital carina. Dorsal margin of antennal scrobe with transverse carina approaching lower margins of eye. Antennal tubercles simple, smooth, closely placed medially. Malar space in frontal view about 0.8 eye height; gena densely covered with white semi-decumbent, brachyplumose setae; genal and postgenal carinae well developed. Clypeus densely covered with erect, brachyplumose to plumose densely-barbed setae, setae white dorsally, blackish ventrally; clypeus with raised area present between antennal bases, subquadrilateral and bordered by carinae in frontal view, triangular in lateral view.Antenna with scape simple, evenly curved, bearing long, densely barbed brachyplumose setae, setae mostly white except for black dorsal setae towards distal end. Pedicel 1.3 as long as wide, 0.6 length of F1; F1 1.7 as long as wide, 1.3 as long as F2. Mandible tapering with subapical inner tooth. Mesosoma pyriform in dorsal view, length 1.5 maximum width, sides diverging slightly to behind prothoracic spiracle and then converging towards propodeum. Dorsal profile lowly convex; propodeum evenly rounded, disc merging into declivity; dorsal sculpture coarsely punctatereticulate; boundaries of mesonotum and propodeum obscured by sculpture. Dorsum of mesosoma with black erect, simple setae; sides and venter of mesosoma with white erect, brachyplumose setae. Anterior margin of mesosoma (excluding pronotal collar) weakly convex; humeral angles rounded. Dorsal face of pronotum laterally margined by strong carina; pronotal-mesopleural boundary marked by distinct sulcus; lateral face of pronotum densely punctate-reticulate dorsally, punctures becoming sparser ventrally. Anterior face of mesopleuron moderately punctatereticulate dorsally, punctures becoming sparser ventrally; posterior face of mesopleuron densely punctate-reticulate, reticules becoming smaller ventrally. Anterior face of metapleuron narrow, smooth; posterior face of metapleuron densely punctate-reticulate; metapleural-propodeal boundary marked by moderate sulcus. Legs: Fore leg with tarsal comb. Mid and hind tibiae each with two spines in longitudinal row on outer margin. Metasoma: T1 about as wide as long, sides diverging from base, minor constriction around apical margin, T1 0.5 width of T2, densely punctate around margins, less so medially; medial setation of T1 white, erect, brachyplumose, with few black, erect, sparsely brachyplumose setae towards posterior margin across high point of T1; posterior margin of T1 behind high point with dense fringe of decumbent white setae. T2 broadly convex, slightly flattened dorsally, sparsely punctate, with semi-decumbent and erect black simple setae dorsally, and white erect, brachyplumose setae along lateral margins; length of felt line 0.3 length of T2; posterior margin of T2 with dense fringe of decumbent black setae, with broad medial spot of white setae. T3–T6 densely punctate, mostly covered with black erect, brachyplumose setae with some white setae laterally, posterior margins with fringes of decumbent black setae without any white setae. S1 mostly evenly convex with anterior median tubercle only. S2 with steep profile anteriorly rounding into slight concavity along greater length. S2–S5 moderately punctate with white, erect, brachyplumose setae; each sternite with dense fringe of white setae along posterior margin; S2 without ventral felt line. S6 moderately punctate with black, long, simple setae.

Male (fig. 2). Total length 4.57–8.26 mm; mesosoma length 2.08–3.16 mm. Integument mostly metallic dark blue with purple gloss, except dark purple tegula, black antenna and tarsi; tibial spurs white. Head in frontal view ovate, 1.4 as wide as long; width of head behind eyes 0.9 width of mesosoma; head densely punctate. Occipital carina well developed dorsally. Sides of head behind eyes converging, rear of head shallowly convex, rear corners of head rounded. Eye ovate, strongly protruding, margins entire; maximum eye diameter 7.3 distance between top of eye and rear of head; minimum frons width 0.6 head width. Vertex convex, ocellar triangle very slightly elevated. Frons and vertex with intermixed shorter white semi-erect, brachyplumose setae and longer black erect, brachyplumose setae; long white, erect brachyplumose setae present above occipital carina. Median ocellus lidded, 0.05 width of head; distance between posterior ocelli 0.8 distance between posterior ocellus and eye; distance between median and posterior ocelli 0.6 distance between posterior ocelli. Antennal scrobe rounded, extending halfway to lower margin of eye, outer margin of scrobe with slight subcircular flange. Antennal tubercle simple, basally punctate, distally smooth, tubercles adjacent medially. Malar space in frontal view 0.4 eye height; gena densely covered with white semi-decumbent brachyplumose setae; genal and postgenal carinae indistinct. Clypeus with ventral margin slightly sinuate. Antenna with scape simple, evenly curved, punctate, bearing white long densely brachyplumose setae. Pedicel 0.7 as long as wide, 0.8 as long as F1; F1 as long as wide, 0.8 as long as F2. Mesosoma mostly densely punctate; propodeum coarsely punctate-reticulate. Propodeum in lateral view with rounded angle between disc and declivity. Pronotum and scutellum with mixed erect, black and white brachyplumose setae; mesoscutum with black erect, brachyplumose setae; propodeum and sides and venter of mesosoma with white erect, brachyplumose setae.Anterior margin of pronotum (excluding pronotal collar) weakly convex; humeral angles obtuse. Length of pronotal midline about 0.7 distance between anteriormost point of mesoscutum and level of tegula. Mesoscutum with strongly marked notaulus on posterior half, extending slightly anterior to level of tegula, broadening posteriorly; parapsidal line reduced to short groove alongside anterior half of notaulus, not extending forward of level of tegula. Tegula subcircular; mostly smooth, evenly convex; rear margin with produced lobe in line with costa, rearmost point at level of mesoscutal-scutellar boundary. Axilla produced into strong rearward-directed lateral tooth, extending to slightly before midlength of scutellum. Scutellum and metanotum both convex medially, excavated laterally, with median section narrowing posteriorly; metanotum with boundary between median and lateral sections not distinctly carinate. Fore wing with distally acute pterostigma, pterostigma 3.2 as long as wide; marginal cell distally truncate, 2.6 as long as wide, with stub of distal spur vein barely present; three closed submarginal cells present, with distal veins of third submarginal cell weak. Legs: Mid and hind tibiae without dorsal spines except for small spine at distalmost point dorsally on hind tibia. Metasoma: T1 slightly longer than wide, sides diverging evenly with slight constriction apically; maximum width of T1 0.5 width of T2; sculpture moderately punctate with white erect, brachyplumose setae. T2 slightly flattened dorsally; densely punctate; with white erect, brachyplumose setae laterally and anteriorly, black simple setae discally and posteriorly; felt line 0.3 lateral length of T2. T3–T6 densely punctate, with mixture of white and black erect setae. T7 with pygidial area indistinct. S1 with low median carina. S 2 in profile with steep anterior face in front of produced anterior mound, followed by slight concavity along greater length; S2 moderately punctate with white erect, brachyplumose setae; very short felt line present laterally, 0.3 length of felt line on T2. S3–S6 weakly punctate, with white, erect, brachyplumose setae. S7 with black erect, simple setae anteriorly, becoming semi-decumbent posteriorly. Genitalia with paramere elongate, narrowly subtriangular in dorsal view, bearing elongate setae along entire length both externally and internally, with particularly dense concentration of setae in proximal half internally; parapenial lobe extending to slightly behind tip of penis valve, slightly curved mesad, rounded terminally; cuspis short, not extending further than penis valve, curved dorsally, very densely setose, ventral lobe not extended; digitus extending shortly beyond penis valve, sharply directed dorsad, extending to dorsal margin of paramere; penis valve with sharp corner between dorsal and apical margins, apical margin almost vertical with few medium-length setae dorsally.

Holotype, ♀. Western Australia: 27 km N Wickepin , 3232’ S 11729 ’E, from nest of Pison tibiale Smith, 1869 , 13 March 2014, M. Murphy (1♀, WAM E 101542; GAN: MK 618708 ).

Paratypes, 9♂♂, 10♀♀. Western Australia: 16 km N Wagin , 3309’ S 11723 ’ E, from nest of Pison fenestratum Smith, 1869 , 23 January 2013, M. Murphy (1♂, WAM E 101543); 20 km S Wagin, 3329’ S 11722 ’ E, from nest of Pison cf. inconspicuum Turner, 1916b , 23 January 2013, M. Murphy (1♂, WAM E 101544; GAN: MK 618684 ); 7 km SW Brookton, 3224’ S 11704 ’ E, from nest of P. fenestratum , 18 February 2013, M. Murphy (2♀♀, 4♂♂, WAM E 101545 –E 101548, E 101550, E 101552; 1♀, 1♂, DJBC; GAN: MK618681 , MK618687 , MK618691 , MK618693 , MK618700 , MK618703 , MK618706 , MK618707 ); 12 km E Brookton, 3221’ S 11708 ’ E, from nest of P. fenestratum , 18 February 2013, M. Murphy (1♀, WAM E 101576; GAN: MK 618699 ); 20 km SW Pingelly, 3241’ S 11657 ’ E, from nest of Pison cf. rufipes Shuckard, 1838 , 13 January 2014, M. Murphy (3♀♀, WAM E 101553 –E 101555); 5 km W Corrigin, 3219’ S 11749 ’ E, from nest of P. fenestratum , 14 February 2014, M. Murphy (2♀♀, WAM E 101557, E 101558; GAN: MK 618696 ); 16 km N Wagin, 3309’ S 11723 ’ E, from two nests of Aulacophilinus mandibulatus (Turner, 1916b) , 12 March 2014, M. Murphy (2♂♂, WAM E 101577, E 101578; GAN: MK618690 , MK618695 ) ;

Comments. Using the key to females provided by Turner (1914), this species comes closest to Aglaotilla metallica ( Smith, 1855) , originally described from South Australia but also recorded by Turner (1916a, 1940) in the south of Western Australia ( André, 1898, gave the distribution of A. metallica as New South Wales; it is unclear whether this was due to further records or simply an error). Turner’s (1914) key described A. metallica as having a longitudinal depression on tergite 2 and the head and mesosoma bronze. Photographs of the holotype of A. metallica (B.M.Type HYM. 15-601, NHMUK 010819767) (fig. 3) confirm the presence of a distinct longitudinal depression on T2 but show the head and mesosoma to be metallic green as in Smith’s (1855) original description. Aglaotilla chalcea sp. nov. differs from A. metallica at least in the coloration of the head and mesosoma (purple with bronze gloss instead of green), in the head shape (less produced behind the eyes), and in the form of the humeral angle (rounded rather than abrupt). T2 of A. chalcea sp. nov. lacks a well-marked depression but is slightly flattened (fig. 1b) and might superficially appear generally depressed in some lights. It is unclear at this time whether Turner’s records refer to the true A. metallica or to A. chalcea sp. nov. or even to another undescribed species. Males of A. chalcea sp. nov. also do not agree with any of the described males assigned to Aglaotilla , most of which are predominantly green or bright blue; none of them has an entirely blue-purple head, body and appendages, as does A. chalcea sp. nov.. Superficially, perhaps the most similar is A. submetallescens , but there the head is green anteriorly and most of the body has golden reflections, most strongly on the posterior metasomal terga; the genitalia are also very different, those of A. submetallescens having the parameres much slenderer and without strong setae (Brothers 2018).

Etymology. Species name a latinized adjective, from the Greek chalkeos, of copper or bronze, in reference to the species’ metallic colour.

Host Records. Specimens were reared from wasp nests. Crabronidae : Aulacophilinus mandibulatus (2 nests, 2♂♂), Pison fenestratum (4 nests, 7♂♂, 6♀♀), P. cf. inconspicuum (1 nest, 1♂), P. cf. rufipes (1 nest, 3♀♀), P. strenuum (2 nests, 2♀♀) and P. tibiale (1 nest, 1♀); Vespidae : Paralastor debilis (1 nest, 1♀).

Figures

FIGURE 1. Aglaotilla chalcea sp. nov., ♀, holotype. A: facial view; B: lateral view; C: dorsal view.