A revision of Tachyphron Brown and description of two new genera within the Ariphron group (Hymenoptera: Tiphiidae)

The Australasian genus Tachyphron Brown is revised, and two new New Guinean genera, Deuterothynnus gen. n. and Heligmothynnus gen. n., described. Fifteen species are included in Tachyphron of which seven are described as new (T. aculeatus sp. n., T. athertonensis sp. n., T. mantonensis sp. n., T. neosubfragilis sp. n., T. nigrisetatus sp. n., T. planus sp. n. and T. townsvillensis sp. n.), and a further two, Aelurus comatus Smith and Aelurus fragilis Smith, transferred from Tachynomyia. Thynnus insularis Smith is transferred from Tachynomyia Guérin to Deuterothynnus and a further three new species, D. fulvicentratus sp. n., D. fulvisetatus sp. n. and D. parallelus sp. n. described. Aelurus atratus Cameron and Takyomyia sabronensis Kimsey are transferred from Tachynomyia and Tachyphron, respectively, to Heligmothynnus and a further two new species, H. microspinus sp. n. and H. neoaratus sp. n. described. T. megacephala (Turner) is synonymized with Tachynoides flavopicta (Ritsema) and, therefore, removed from Tachyphron. A key to the Ariphron group of genera is provided, as well as keys to the males of Tachyphron, Deuterothynnus and Heligmothynnus, although the male of D. insularis is associated tentatively with the female holotype only on the basis of collection records. Only the females of D. insularis, T. armidalensis Brown and T. subtriangularus Brown are known, the latter two being described for the first time. Evidence is presented to suggest that T. subtriangularus may be bivoltine in northern Australia.


Introduction
The Tiphiidae is related to the Formicidae, Mutillidae, Pompilidae, Scoliidae and Vespidae, and together with the Bradynobaenidae, Rhopalosomatidae, Sapygidae and Sierolomorphidae form the Vespoidea (Goulet and Huber 1993). It is a varied and widely distributed family of aculeate wasps. They vary in size from about 3 mm to 3 cm, and exhibit slight to extreme sexual dimorphism, depending on subfamily. Wasps of this family are most readily recognized by the presence of mesosternal lamellae which are directed posteriorly and cover the bases of the mesocoxae. Sexual dimorphism varies between The diversity of undescribed species akin to Tachyphron, together with the apparent discontinuous distribution of Tachynomyia between southern Australia and the island of New Guinea, prompted this study. The latter genus is large with 29 described species (Brown 2001) and needs to be revised. If it is typical of other Australian genera, then it probably contains at least twice as many undescribed species (see Brown 1987Brown , 1989aBrown , 1989b for revisions of Acanthothynnus Turner, Doratithynnus Turner and Encopothynnus Turner). Similarly, Tachynoides currently contains four described species while Ariphron has 11 (Brown 2001), and I am aware of at least another eight and 20 species in these genera, respectively.
Despite the size of the Australian fauna, almost nothing is known of the biology of the Thynninae, although an overview was given by Brown (1998). They are believed to be idiobiont ectoparasitoids of scarab larvae, but this is based on less than 20 records, and it is likely that other soil-dwelling larvae are also parasitized. This has been implied by Campbell and Brown (1994), who monitored the abundance and diversity of scarabs and scarab parasites on the northern tablelands of New South Wales. They found at least 58 species of tiphiid (as well as four scoliids and 24 tachinids) that were potential parasitoids of 25 species of scarab recorded from the site. This high number of species of tiphiids compared with the number of available scarabs suggested that non-scarabs were also parasitized by some species, although none was found.
Several groups are orchid pollinators, especially some species within several genera including Arthrothynnus Brown, Eirone Westwood, Iswaroides Ashmead, Neozeleboria Rohwer, Phymatothynnus Turner, Thynnoides Guérin and Zaspilothynnus Ashmead. Males are attracted to orchid flowers which produce pheromone-mimicking chemicals. Once attracted, a male will attempt to copulate with the flower, and in the process pollen transfer may occur. Most of these wasp-flower relationships appear to be species specific (although it should not be confused with nectar-producing orchids such as Prasophyllum spp. which have generalist nectar-feeding pollinators) (Adams and Lawson 1993;Bower and Brown 1997).
Little is known of the life cycles of thynnines. Campbell and Brown (1998) also found that tiphiids, including the type species of Tachyphron, T. subtriangularus Brown, were univoltine. This had also been demonstrated for Tachynomyia adusta (Smith) and three other species previously on the northern tablelands of New South Wales by Ridsdill-Smith (1970). This is the only known data on the seasonal occurrence of Australian thynnines.
Male thynnines are fully winged, and are readily collected in Malaise traps. However, the sexes are completely dimorphic with females apterous and ant-like in appearance. While pairs do fly in copula, females are less often collected and are unknown for many species.

Materials and methods
Terminology follows Turner (1910), Snodgrass (1941) and Brown (2001). Microsculpture is interpreted as follows: sparsely punctate5punctures further than two puncture-diameters apart; punctate5punctures at most two puncture-diameters apart but not confluent; closely punctate5punctures almost confluent; rugosely punctate5punctures partially confluent; finely5small and shallow; and coarsely5large and deep. In the genera described here (as well as Tachynomyia and Tachynoides) the head is strongly concave in the male. The origin of this is unclear, but appears to be a specialized region of the gena (rather than the hypostoma as interpreted earlier ; and is here referred to as the genal cavity. Genal length is difficult to quantify because it usually becomes wider dorsally (Figures 1,  2). It is here approximated as the ratio of its length measured near the mid height of the eye to the minimum diameter of the eye. In the majority of species it is distinctly less than half, but distinctly greater than a quarter, of the diameter of the eye.

Taxonomic accounts
Ariphron group of genera The Ariphron group of genera was so termed by Kimsey (1996) to include Ariphron, Tachynoides, Tachynomyia and Tachyphron (as the junior synonym Takyomyia) on the basis of the structure of the face and the apex of the abdomen in the male and the presence of a broad, flattened longitudinal welt on the apical abdominal tergum in the female. The males of all these genera, except Ariphron, have the posterior surface of the head strongly concave and polished with a lateral fringe of long setae (Figures 1, 3). This cavity is unique amongst the Thynninae and is one of the most striking diagnostic characters within the group. The relationships between these genera have been discussed in detail by Kimsey (1996) and Brown (2001). The two new genera described here, Deuterothynnus and Heligmothynnus, also fit within this group, and also have the head strongly concave.
An examination of all available specimens of Tachyphron and species akin to it has revealed the existence of 24 species. These are almost identical in gross external appearance but show some variation in the length of the gena and vertex, the size of the genal cavity, microsculpture, the length and width of T1, and the colour of the metasoma. However, they show major differences in the structure of the genitalia and the shape of the hypopygium, and form three groups on the basis of these structures. These differences are considered to be of generic value, and as significant as those differentiating Tachyphron and Tachynoides as discussed by Brown (2001). The 24 species revised here belong to Tachyphron, Deuterothynnus and Heligmothynnus, and are those that either key to Tachyphron in couplet 3 in Brown (2001) or cannot be placed in either this genus or Tachynoides at that couplet. The latter genus also contains numerous species and will be revised at a later date.
At the species level, the length of the gena is one of the few useful non-genitalic diagnostic characters, and which was used by Kimsey (1996) to distinguish Tachynoides from Tachyphron (as Takyomyia). However, it varies considerably between closely related species (based on similarities in the structure of the genitalia) in each of the three genera revised here and is, therefore, not considered to be of diagnostic value at the generic level.

Tachynoides Kimsey
Deuterothynnus gen. nov. Type species: Deuterothynnus fulvisetatus sp. n. Etymology. The generic name is derived from the Greek word deuteros meaning second, and is a reference to both a second large apical spine on the hypopygium and a secondary smaller preapical spine.
Diagnosis. Male: hypopygium deeply emarginate medially between two long spines, and a smaller preapical spine on the outer margin of these long spines.
Description. Male: similar to Tachyphron, but differs by having the hypopygium deeply emarginate medially between two long spines, a smaller preapical spine on the outer margin of these long spines (Figures 13-16) and the genitalia  with (1) the basiparameres long and (collectively) narrowly triangular or narrowly subparallel with the lateral margins straight over most of their length; (2) parameres (viewed laterally) usually broad over most of their length; and (3) the aedeagus differentiated into a small basal hoodlike structure without ventral lobes and apically into a long and often convoluted filament.
Remarks. Four species, D. fulvicentratus, D. fulvisetatus, D. insularis and D. parallelus, from New Guinea (including Irian Jaya) or the adjacent island of Misool are known ( Figure 59). All are recorded from a single locality and from at most two specimens.
The only known female specimen, the holotype of Deuterothynnus insularis (Turner) comb. nov., apparently has been lost, and the original description is insufficient to provide a diagnosis.
Key to males of Deuterothynnus (only the female of D. insularis is known but the holotype could not be located)  lateral margins subtriangular ( Figure 8) and parameres with ventral margin straight with apex straight and narrow (Figure 7) . . . . . . . . insularis Turner -Propodeum closely to rugosely punctate; genitalia with basiparameres (collectively) with lateral margins subparallel ( Figure 6) and parameres with ventral margin curved with apex curved and broad ( Figure 5)  Distribution. Known only from lowland rainforest in the Lakekamu Basin, Papua New Guinea ( Figure 59).
Etymology. The specific name is a combination of the Latin words fulvus meaning redyellow and centratus meaning centre. It is a reference to the orange of the first two metasomal segments.

Remarks.
The left antenna is incomplete. Distribution. Known only from montane primary rainforest, Wapoga, Irian Jaya ( Figure  59).
Etymology. The specific name is derived from Latin words fulvus meaning red-yellow and seta, and is a reference to the orange coloration of the setae.
Distribution. Known only from Mysol Island near the western tip of Irian Jaya ( Figure 59).
Remarks. The depository of the holotype female is unknown. Smith's (1864) original description gives no indication of this. Although it is presumed to be either the Natural History Museum or Oxford University, it cannot be located at either institution (S. Lewis, personal communication; C. O'Toole, personal communication). Salter (1963) listed the depository as Oxford, but he was unable to examine the holotype for some unstated reason. Kimsey (1996) indicated that she had examined the holotype, but she did not cite the depository, and there are many errors in her lists (Brown, 2001).
The male is tentatively placed in this species based on distribution. The label on the male is old, and may prove to be identical to that of the female when it is found. It is on this basis, as well as the absence of any other species of Tachynomyia from the island of New Guinea and surrounding islands, that this species is removed from Tachynomyia and transferred to Deuterothynnus.
Half of the left antenna and the tip of the right antenna are missing in the male.
Etymology. The specific name is Latin for parallel, and is a reference to the shape of the basiparameres viewed dorsally.
Etymology. The generic name is derived from the Greek word heligma meaning curled and is a reference to the long coiled apical filament of the aedeagus.
Diagnosis. Male: medial apical spine on the hypopygium small. Aedeagus with basal hoodlike structure with paired rounded apical lobes on the ventral margin laterally, and apical long and strongly coiled tape-like structure.
Description. Male: similar to Tachyphron, but differs by having the apical hypopygial spine short and small , and the genitalia (Figures 17-24) with (1) the basiparameres long and wide viewed both laterally and dorsally, and broadly emarginate apically; (2) the parameres narrow with the margins strongly curved and/or strongly convergent such that they almost appear sinusoidal in profile; and (3) the aedeagus differentiated into a basal hood-like structure with paired rounded apical lobes on the ventral margin laterally, and apically into a long and strongly coiled tape-like structure.
Distribution. Known only from Biak Island off the northern coast off Irian Jaya ( Figure 59).

Description.
Male: black; small medial spot on metanotum yellow; metasoma dark brown; tegulae brown; wings 'hyaline, the nervures and stigma black, a fuscous cloud filling the basal half of radial cellule, the 1st cubital between the ''stump'' of a nervure and the stigma, the 2nd and 3rd cubital cellules, the 2nd discoidal cellule and the part beyond it to near the 2nd recurrent nervure' (Cameron, 1911); setae white. Clypeus closely and finely punctate, apically truncate, sagittal carina obscure dorsally. Frons and vertex rugosely punctate.
Gena finely punctate, slightly oblique, approximately half length of minimum eye diameter. Occipital carina visible dorsally. Genal cavity visible dorsally. Pronotum including anterior surface rugosely punctate. Mesoscutum rugosely punctate. Mesoscutellum rugosely punctate. Metanotum finely punctate. Propodeum closely and shallowly punctate. Mesopleura finely rugosely punctate. T1-6 shallowly and sparsely punctate; T7 closely and coarsely punctate, impunctate medially; T1 with length: width 2.1:1. S1-8 shallowly and sparsely punctate. Hypopygium (Figure 27) subparallel, lateral spines short, acute not divergent, apical spine subtriangular and as long as lateral spines. Genitalia (Figures 19,20) with parameres long, narrow and curved over most of length, dorsal margin straight basally, apices strongly down-turned, rounded, not divergent; basiparameres in dorsal view subtriangular, apex emarginate and ending beyond level of apices of cuspides, broad in lateral view; aedeagus with basal and apical sections, basal section short, swollen and hoodlike with a pair of divergent ventral lobes that originate from inside (rather than the margin of) the basal section, apical section missing but presumed to be extremely long, filamentous and coiled, and much longer than length of parameres. BL: 12.
Remarks. The holotype is missing most of the antennae and all wings except the right hind wing which is damaged. Most of the aedeagal coil is also missing.
( Figures 17, 18 Distribution. Known only from lowland wet forest in the Lakekamu Basin, Central District, Papua New Guinea ( Figure 59).
Etymology. The specific name is derived from Greek, and is a reference to the minute apical hypopygial spine.
Description. Male: black; metasoma (except T1 and S1) red or at most red slightly infused with black; anterior margin of pronotum (narrowly interrupted medially), and disc of metanotum yellow; flagellum and tarsi ventrally, dark brown; setae white; wings hyaline without preapical spot on fore wing; veins dark brown to black.  Figure 26) subparallel, lateral spines short and triangular, and longer than apical subtriangular spine. Genitalia (Figures 17, 18) with parameres long and narrow, subparallel basally with dorsal margin straight, down-turned and narrower apically, apices rounded, slightly divergent, ending beyond apex of aedeagus (when coiled); basiparameres in dorsal view subtriangular, apex emarginate and ending beyond level of apices of cuspides, broad in lateral view; aedeagus with basal and apical sections, basal section short, swollen and hood-like with a pair of ventral lobes that originate from inside (rather than the margin of) the basal section, apical extremely long, filamentous and coiled (maceration in KOH causes the coil to intensify and tighten such that it is more coiled and the coil diameter is smaller), much longer than length of parameres. BL: 9-13; FW: 6-10; HW: 4-7.
Etymology. The specific name is derived from Greek, and is a reference to the similarity of this species to H. atratus.
Description. Male: black; anterior margin of pronotum (narrowly interrupted medially) and medial spot on metanotum yellow; tegulae testaceous with yellow basal band; wings infuscate with dark preapical spot on fore wing; veins and stigma brown; setae white. almost impunctate except posterolaterally; T7 closely and coarsely punctate, impunctate medially; T1 with length: width 1.9:1. S1 shallowly and sparsely punctate; S2-8 almost impunctate but becoming punctate posterolaterally. Hypopygium ( Figure 28) subparallel, lateral spines short, acute and divergent, apical spine subtriangular and as long as lateral spines. Genitalia (Figures 21, 22) with parameres long, narrow and curved over most of length, dorsal margin curved basally, apices strongly down-turned, rounded, divergent, ending beyond apex of aedeagus (when coiled); basiparameres in dorsal view subtriangular, apex emarginate and ending beyond level of apices of cuspides, broad in lateral view; aedeagus with basal and apical sections, basal section short, swollen and hood-like with a pair of ventral lobes that originate from inside (rather than the margin of) the basal section, apical section extremely long, filamentous and coiled (maceration in KOH causes the coil to intensify and tighten such that it is more coiled and the coil diameter is smaller), much longer than length of parameres. BL: 13; FW: 10; HW: 6.
Heligmothynnus sabronensis (Kimsey 1996)  Diagnosis. Male: hypopygium with lateral margins straight and diverging posteriorly, and the apical spine broadly triangular and as long as the lateral spines. Gena less than quarter length of minimum eye diameter. Fore wing without a preapical spot. Metasoma red-brown to black, but not uniformly black. Dorsal margin of parameres slightly sinusoidal and dentate slightly before apex of basiparameres (Figures 23, 24).
Diagnosis. Male: head with posterior surface strongly concave, margin of concavity fringed with long setae (Figure 1). Gena not ventrally produced into a digitate process near the mandible. Basiparameres collectively (viewed dorsally) subtriangular, not emarginate apically. Aedeagus (viewed dorsally) subparallel and narrow, usually long and usually without lobes; not filamentous apically or with a basal hood.
Female: mesopleura with lateral surface produced and strongly angulate with a vertical carina ventrally. Mesoscutellum without median longitudinal depression. T2 not transversely carinate. Pygidium subovate with well-developed microsculpture, which may obscure the median welt, and often with setal brushes. (It should be noted that this diagnosis is based on only the females of T. armidalensis and T. subtriangularus. The presence of a median longitudinal depression on the mesoscutellum appears to distinguish Tachynoides from this genus in both sexes, but is slight in Tachynoides flavopicta (Ritsema), and more females of both genera need to be discovered before the diagnosis can be fully tested.) Remarks. Sixteen species are known as listed below: nine from the northern half of mainland Australia, four from Papua New Guinea, and one each from the Indonesian islands of Halmahera, Morotai and Waigeo. All non-Australian species are known from at most either two locations and/or two specimens. The majority of Australian species are also poorly represented in collections with only a few specimens known. The best represented are T. aculeatus, T. planus and especially T. armidalensis and T. subtriangularus.
The majority of species clearly fit into one of two groups. The nine Australian species form a group on the basis of the male genitalia which have: the basiparameres narrowly triangular and short (relative to the length of the parameres); the aedeagus long and narrow (viewed dorsally) and often segmented but not coiled; the parameres usually long and narrow and often twisted, flattened or strongly narrowed at least apically; and the metasoma always black.
The Indonesian and Papua New Guinean species, with the exception of T. halmaherensis and T. fragilis, form the second group on the basis of the male genitalia which have: the parameres (in profile) relatively broad basally and narrowed (usually abruptly and obliquely digitate) apically; a tendency for the basiparameres to be notched near the apex; and a tendency for the cuspides with a curved apical knob. There is also a tendency for the metasomal segments to be at least partially lighter in colour and ranging from dark brown to red. T. fragilis is associated with this group only on the presence of the preapical notch on the basiparameres, but the genitalia is otherwise distinctive within the genus. Similarly, the genitalia of T. halmaherensis is also distinct within the genus.
Etymology. The specific name is Latin for sharp pointed, and is a reference to the shape of the parameres.
Diagnosis. Male: hypopygium with apical spine broadly triangular and relatively blunt, apex slightly beyond level of lateral spine apices ( Figure 58). Parameres long and narrowly triangular in both profile and viewed dorsally (Figures 43, 44).
Diagnosis. Male: hypopygium with apical spine large and broadly triangular and the lateral spines relatively small (see Brown 1995b: Figure 5). Aedeagus long and narrow with the apex narrowed and slightly down-turned, and the dorsal margin of the ventral lobe curved (see Brown 1995b: Figure 15). Gena short and approximately quarter length of minimum eye diameter (see Brown 1995b: Figure 7; 2001: Figure 14).
Female: frons and vertex with a semicircular area of finer punctures interspersed between deeper punctures. Pygidium strongly narrowed dorsally with two medial longitudinal carinae (see Brown 2001: Figure 19).
Description. Female: brown; antennae and legs slightly paler. Head subrectangular, slightly wider than long, posterior angles rounded, eyes relatively large, not strongly protuberant, almost reaching base of mandibles. Mandibles long, evenly curved, without preapical tooth. Clypeus narrowly truncate apically, closely and finely punctate, sharply medially carinate basally to near apical margin. Frons obscurely sagittally sulcate. Frons and vertex deeply rugosely punctate interspersed with small shallow punctures in a large semicircular area bounded by the inner orbits of the eyes and most of the vertex (except laterally and posteriorly). Pronotum trapezoid with lateral margins converging posteriorly, dorsal and lateral surfaces clearly delineated from dorsum, margins not carinate, dorsum rugosely punctate, punctures aligned longitudinally, lateral surface longitudinally multistriate with striae subparallel to ventral margin becoming rugosely punctate dorsally. Mesoscutellum trapezoid, closely punctate. Propodeum closely to rugosely punctate dorsally, rugosely punctate posteriorly, longitudinally striate laterally. Mesopleura with small dorsal surface below level of mesoscutellum, produced anterolaterally into a vertical carina. Metasoma rugosely punctate, punctures longitudinally aligned, T1-5 with posterior line of longitudinal punctures blending in with other punctation; T6 almost smooth medially, longitudinally, striations short, confluent and appearing as two parallel lines medially, with lateral fringe of setae, lateral margins strongly convergent dorsally, apical margin not broadly rounded, narrowly emarginate; T1 with vertical declivity anteriorly; S1 short, broad, medially raised, not carinate; S6 with weakly raised lip on posterior margin. BL: 8.
Remarks. This is the most southern species, and is the only species found outside tropical Australasia.
The female has not been described previously, and apart from T. subtriangularus, is the only known female for this genus.
Etymology. The specific name is derived from the type locality.
Diagnosis. Male: hypopygium with apical spine long and narrowly triangular ( Figure 55). Aedeagus long, narrow and straight with the apex expanded, and the dorsal margin of the ventral lobe straight (Figure 42).
Diagnosis. Male: hypopygium with apical spine long and narrow and upturned apically and broadly triangular basally ( Figure 32). Aedeagus expanded and truncate apically ( Figure  37). Parameres long, narrow and curved over much of their length. Metasoma black.
Distribution. Known only from Mondo, Papua New Guinea (Figure 60).
Diagnosis. Male: metasoma black with T6-7 and S6-8, and the posterior and lateral margins of T2-5 and S2-5, red-orange and the antennae black. The genitalia have the apical lobe of the parameres digitate, twisted, divergent and appearing as a short downturned digitate process in profile, ending beyond apex of aedeagus. Aedeagus short and ending before the apex of the parameres, and the basiparameres long (see Brown 2001: Figures 26, 27).
Remarks. The gena and genitalia illustrated as this species by Kimsey (1996) do not belong to this species (Brown 2001).
Remarks. Kimsey cited the original combination as Trachypterus fragilis Smith, although this species has never been placed in that genus. Trachypterus Dalla Torre is a junior synonym of the monotypic Diamma Westwood. This genus belongs to the subfamily Diamminae, not Thynninae.
Diagnosis. Male: gena very short, less than quarter length of minimum eye diameter. Hypopygium with the apical spine long and narrow apically and broadly triangular basally, and the lateral spines long, acute and slightly divergent ( Figure 54). Aedeagus with apical section narrow, subparallel and sinusoidal over most of length becoming swollen apically with apex minutely spinose (Figures 51, 52). Metasoma dark brown.
Remarks. The specimen labelled as the holotype by Kimsey is dated 1-14 February 1981, not 14-21 February 1991 as stated by Kimsey (1996). Distribution. Known only from a roadside picnic area at Manton River south of Darwin, Northern Territory ( Figure 60).
Etymology. The specific name is derived from the type locality.
Diagnosis. Male: hypopygium with the apical spine broad and subparallel apically with apex upturned, but appearing blunt when viewed ventrally ( Figure 56). Aedeagus with a long narrow ventral lobe ( Figure 45).  Figure 56) subparallel, lateral spines acute and curved, apical spine broad and subparallel with upturned apex but appearing blunt when viewed dorsally. Genitalia (Figures 45, 46) with parameres subtriangular, apices rounded, slightly down-turned, slightly divergent, ending before the apex of aedeagus; basiparameres in dorsal view subtriangular, apex weakly emarginate and ending before the level of apices of cuspides, narrow (especially basally and apically) in lateral view; aedeagus with basal and apical sections, basal section narrow with long narrow ventral lobe, apical section long, narrow and subparallel over most of length then abruptly narrowed near apex, ending beyond apex of level of apices of cuspides. BL: 8; FW: 6; HW: 5.
Remarks. I have been unable to collect further specimens of this species, despite frequent attempts. Distribution. Known only from Baiyer River cattle station, Papua New Guinea (Figure 60).
Etymology. The specific name is derived from Greek, and is a reference to the similarity of this species to T. subfragilis.
Diagnosis. Male: hypopygium with apical spine broadly triangular and only slightly longer than the lateral spines ( Figure 30). Parameres long and narrow apically with the apices divergent (Figures 35, 36). Aedeagus strongly curved with apex directed upwards.  Figure 30) subparallel, lateral spines short and acute, apical spine broadly subtriangular. Genitalia (Figures 35,36) with parameres subparallel basally becoming narrower apically, apices twisted and divergent and appearing as a long digitate process in profile, ending before apex of aedeagus; basiparameres in dorsal view broadly triangular without preapical notches, apex not clearly differentiated from aedeagus and apparently rounded, ending slightly beyond level of apices of cuspides, broad in lateral view; aedeagus with distinct basal and apical sections, basal section short and ovoid without ventral lobes, apical section expanded basally then long, narrow, parallel and hook-shaped, ending beyond level of apices of parameres. BL: 11; FW: 8; HW: 6.
Etymology. The specific name is derived from Latin, and is a reference to the black setae found on most of the head and body.
Etymology. The specific name is Latin for flat, and is a reference to the flattened parameres.
Diagnosis. Male: gena approximately half the length of minimum eye diameter. Hypopygium with apical spine triangular but not broadly triangular ( Figure 53). Parameres flattened apically (Figures 49, 50). Cuspides short (Figure 50).  Figure 53) subparallel, lateral spines acute, apical spine triangular. Genitalia (Figures 49, 50) with parameres long, subtriangular and slightly down-turned, appearing acute in profile and flattened and truncate with the inner angle of truncation slightly produced mesally in dorsal view, ending before apex of aedeagus; basiparameres in dorsal view triangular, apex narrowly rounded, ending before level of apices of cuspides, narrow (but obscured by parameres) in lateral view; aedeagus with basal and apical sections, basal section subparallel but slightly expanded apically, without ventral lobes, apical section swollen basally, and curved and tapering to an acute apex, ending beyond level of apices of parameres. BL: 9-11; FW: 6-8; HW: 4-5.
Distribution. Known only from the ranges of south-eastern Papua New Guinea (Figure 60). Clypeus narrowly truncate apically, closely and finely punctate, sharply medially carinate basally to near apical margin. Frons weakly sagittally sulcate, rugosely punctate with punctures weakly longitudinally aligned on antennal prominence, punctures variable in size. Vertex closely punctate, punctures variable in size and spacing. Pronotum trapezoid with lateral margins converging posteriorly, dorsal and lateral surfaces clearly delineated from dorsum, margins not carinate, dorsum closely punctate with some punctures aligned longitudinally, lateral surface longitudinally multistriate ventrally with striae subparallel to ventral margin. Mesoscutellum trapezoid, closely punctate. Propodeum closely punctate dorsally, rugosely punctate posteriorly, longitudinally striate laterally. Mesopleura with small dorsal surface below level of mesoscutellum, produced anterolaterally into a vertical carina.
shallowly punctate, punctures deeper on posterior segments. Hypopygium (Figure 57) subparallel, lateral spines acute, apical spine triangular. Genitalia (Figures 47, 48) with parameres subparallel with apex twisted and appearing flattened apically, ending before apex of aedeagus and slightly beyond level of apices of cuspides; basiparameres in dorsal view triangular, margins slightly sinusoidal, apex acute, ending before level of apices of cuspides, narrow in lateral view; aedeagus with basal and apical sections, basal section long, subparallel and slightly curved, without ventral lobes, apical section with ventral margin curved upwards apically and dorsal margin sinusoidal, ending beyond level of apices of parameres. BL: 9; FW: 7; HW: 5.
Remarks. The genitalia of the holotype of Tachynomyia megacephala are identical to those of the type series of Tachynoides flavopicta (Ritsema) from the Indonesian Island of Aru, and held in the Rijksmuseum van Natuurlijke Historie, Leiden. On the basis of this, this species is synonymized with Tachynoides flavopicta and the species therefore removed from Tachynomyia.

Discussion
The distributions of Deuterothynnus and Heligmothynnus are restricted to New Guinea and adjacent islands ( Figure 59). All species are known from only one or two specimens and from a similar number of locations. As a result little is known of the distribution of individual species. However, the ruggedness and inaccessibility of much of this area raises the possibility that the fauna may be found to be much larger after extensive collecting. This is also suggested by the number of new species collected at Freeport (D. fulvisetatus, D. parallelus, H. neoaratus) and Lakekamu (D. fulvicentratus, H. microspinus and also T. nigrisetatus) using Malaise traps. These traps are particularly effective in collecting thynnines when males are flying.
The distribution of Tachyphron overlaps that of Deuterothynnus and Heligmothynnus in New Guinea, but is also widespread in northern Australia. Most species are also known from very few specimens, with the greatest diversity occurring in the Northern Territory in the vicinity of Darwin, and in northern Queensland north from Townsville (Figures 60, 61). Only four species are known from more than two specimens. These are T. armidalensis, T. subtriangularus, T. aculeatus and T. planus, with the first two being the best represented.
T. armidalensis is the only species found outside the tropics. It ranges from south-eastern Queensland to the northern tablelands of New South Wales. Most specimens were collected as part of a research project between 1991 and 1994 on the distribution and seasonal occurrence of scarab parasites as outlined by Campbell and Brown (1994). This work was undertaken on two adjacent properties near Wollomombi on the northern tablelands of New South Wales using 20 Malaise traps that were set at various distances from remnant vegetation stands and monitored at weekly intervals. Campbell and Brown found that T. armidalensis occurred only between December and April with a population peak in January or February, and that there was no evidence of more frequent generations for any of the 58 plus species collected at the site (Campbell and Brown 1998).
T. subtriangularus is the most widely distributed species, occurring in the northern parts of the Northern Territory and adjacent areas of Queensland and Western Australia. Unlike the univoltine T. armidalensis, T. subtriangularus has been collected in most months of the year with possible peaks in October to December, and April to May. These peaks may be artificial as many of the specimens were collected during organized collecting trips to Darwin and Kakadu National Park in December 1993, Lawn Hill Nature Reserve in April 1995and Melville Island in October 1996. However, Malaise trap catches in 1991 at Berry Springs and Howard Springs tend to support two peaks in adult numbers. This is the first evidence to suggest that there may be more than one generation per year in Australian thynnines.
Both T. aculeatus and T. planus have been collected in all months between February and May, but there are insufficient specimens to determine if these tropical species are univoltine or bivoltine.