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Research Article
A review of the genus Trichoura Londt, 1994 with the description of a new species from the Northern Cape Province of South Africa and a key to world Willistonininae (Diptera, Asilidae)
expand article infoJason G.H. Londt, Torsten Dikow§
‡ KwaZulu-Natal Museum, Pietermaritzburg, South Africa
§ National Museum of Natural History, Smithsonian Institution, Washington, DC, United States of America
Open Access

Abstract

The South African assassin-fly genus Trichoura Londt, 1994 is reviewed. A new species, Trichoura pardeos sp. n., is described from the arid Karoo in north-western South Africa. A new key to all seven recognized species is provided and the distribution and phenology are discussed. The world fauna of Willistonininae is reviewed, a new taxon Sisyrnodytini tribe n. (type genus Sisyrnodytes Loew, 1856) is established for Ablautus Loew, 1866, Acnephalomyia Londt, 2010, Ammodaimon Londt, 1985, Astiptomyia Londt, 2010, Sisyrnodytes, and Sporadothrix Hermann, 1908 and photographs for all Willistonininae genera are provided.

Keywords

Assassin flies, robber flies, Afrotropical, Nearctic, new tribe, new species

Introduction

The Afrotropical asilid genus Trichoura Londt, 1994 is of particular interest. Not only is it currently a South African endemic associated with rather arid environments, but, in an Afrotropical context, it is believed to be most closely related to a number of Afrotropical genera previously included in the Stenopogoninae (Dikow 2009a), some of which are in some respects rather different. Other genera to which Trichoura is related are Willistonina Back, 1909 and Ablautus Loew, 1866 (Dikow 2009a), both known from the Nearctic Region only (E.M. Fisher pers. comm.).

The discovery of a new species requiring description provides an opportunity to review the genus and highlight its interesting taxonomic position.

The taxonomic history of Trichoura is short and uncomplicated and can be briefly summarised as follows:

Londt (1994) – Described the genus, placing it within the subfamily Stenopogoninae. Six South African species were included, all being described for the first time (T. krugeri, T. mesochora, T. proctomeces, T. tankwa, T. torynopoda, T. tyligma). A key for the identification of Afrotropical Stenopogoninae was provided.

Dikow (2009a) – Included the genus in a phylogenetic study based on morphological characters and allocated it to his new subfamily Willistonininae (previously considered to have the status of a tribe (Willistoninini Artigas & Papavero, 1991) within the Stenopogoninae sensu Artigas & Papavero (1991) and Geller-Grimm (2004) along with two other Afrotropical genera (Acnephalum Macquart, 1838 and Sisyrnodytes Loew, 1856). Two Nearctic genera (Willistonina and Ablautus) were also included in this taxon.

Londt (2009) – Reviewed Afrotropical Sisyrnodytes, a primarily Afrotropical genus with a few Palaearctic representatives.

Londt (2010) – Reviewed the Afrotropical Acnephalum fauna, demonstrating that Afrotropical species were not congeneric with the Palaearctic type species (A. olivierii Macquart, 1838), and so transferred the Afrotropical species to a new genus, Acnephalomyia Londt, 2010. He also re-combined Acnephalum cylindricum (Hermann, 1907), the species included in Dikow (2009a) which had been moved into Acnephalum by Oldroyd (1974), with Sporadothrix.

Londt (2013) – Provided an updated key to the Afrotropical genera of Stenopogoninae, retaining Trichoura in the subfamily in the absence of a key to the subfamilies recognised by Dikow (2009a).

Londt and Dikow (submitted) – In reviewing the Afrotropical Asilidae fauna added several genera of Stenopogoninae sensu Artigas & Papavero (1991) and Geller-Grimm (2004) to the Willistonininae (Ammodaimon Londt, 1985, Acnephalomyia Londt, 2010, and Astiptomyia Londt, 2010).

Materials and methods

Terminology follows mainly that proposed by McAlpine (1981), Stuckenberg (1999), Cumming and Wood (2009), Wootton and Ennos (1989, wing venation) as well as that used by the senior author in more recent publications. Specimens available for study are housed in the following institutions: KwaZulu-Natal Museum, Pietermaritzburg, South Africa (NMSA); National Museum of Natural History, Washington, DC, U.S.A. (USNM). Label data is cited as it appears on labels, lines of data being separated by a slash (/). While more recently collected specimens are often provided with detailed information relating to locality and habitat, it has been necessary to attempt to establish precise geographic coordinates for older or relatively poorly documented material in order to gain a better appreciation of species distribution. Google Earth and the Internet have been used to accomplish this. Information not appearing on labels is provided in square brackets. A wing was removed, placed in alcohol and flattened between glass microscope slides for photography. Terminalia were excised and macerated in hot Potassium Hydroxide (KOH) before being drawn with the aid of a drawing tube. Photographs of pinned specimens are available in digital format at Morphbank (Collection ID #860612). The distribution map is available in digital format at SimpleMappr (6129 - http://www.simplemappr.net/map/6129) and Google Earth (6129 KML file - http://www.simplemappr.net/map/6129.kml).

Results

Taxonomy

Trichoura Londt, 1994

Figs 1–6, 7–8

Type species

Trichoura torynopoda Londt, 1994: 93 by original designation.

Diagnosis

Small, brown-yellow, strongly silver pruinose asilids with the following combination of characters: Head: Clearly wider than high in anterior view; mystax white, macrosetae tightly packed, confined to a slight gibbosity on lower facial margin; face narrow, frons diverging abruptly from level of antennal sockets; macrosetae on lateral margin of frons; palpi small, 2-segmented. Thorax: Anterior anepisternal setae absent; anatergites asetose; postmetacoxal area membranous. Wing: Transparent, immaculate, fairly uniformly microtrichose; alula reduced in size; C extends almost entirely around wing margin (weakly after junction of CuA and CuP), cells m3, and cua closed and stalked. Legs: Pulvilli and empodia well developed; metathoracic coxae with an anteriorly situated protuberance. Abdomen: ♂ terminalia unrotated; ♂ epandrium commonly with long, silvery, prone setae masking shape; hypandrium absent or fused with well-developed gonocoxites which are fused medially to form a cup-shaped sclerite supporting gonostyli and other elements of the terminalia.

Figures 1–6.

Photographs of Trichoura: 1 male T. tankwa (USNMENT01115152), dorsal (Morphbank #860636) 2 same, lateral (#860638) 3 same, head anterior (#860640) 4 male T. torynopoda (USNMENT01295405) head anterior (#860659) 5 same, dorsal (#860655) 6 same, lateral (#860657). Scale bars: 1 mm.

Figures 7–9.

Photographs of Trichoura tankwa and habitat: 7–8 female fly perching on low, dry branch (Morphbank #860609; #860611) 9 Little Karoo veld habitat at De Zeekoe Guest Farm near Oudtshoorn, Eastern Cape, South Africa (33°37'26"S 022°08'39"E). Photographs by T. Dikow.

Trichoura pardeos sp. n.

Figs 10–12, 15–19

Etymology

Gr. Pardos m. – leopard + oros, -eos n. mountain. Named after the type locality of Tierberg Nature Reserve (Tierberg meaning tiger (= leopard) mountain).

Description

Based on all available NMSA material.

Head: Dark red-brown to black, but colour masked by strong silver and gold pruinescence, white and pale yellow-white setose. Antennal scape and pedicel brown-orange, postpedicel and terminal style dark red-brown, fine silver pruinose, scape and pedicel yellow-white, short setose, style tipped with almost transparent spine-like sensory element. Segmental ratios (scape (as 1) : pedicel : postpedicel : style (segment + sensory element) – 1 : 1.4 : 3.8 : 1.2 (0.8 + 0.3). Face dark red-brown to black, but colour masked by strong silver pruinescence, profile plane except for slight epistomal gibbosity. Mystax shiny white, moderately well-developed, confined to small epistomal gibbosity, setae closely arranged forming a dorsoventrally compressed shield covering proboscis. Face narrow, parallel-sided, width of face: width of head (at widest point) ratio – 1 : 8.2: 2.2. Frons and vertex somewhat divergent, width of face to width of vertex (at level of anterior ocellus) ratio – 1 : 2.2, dark red-brown to black, but colour masked by strong silver (frons) and weak gold pruinescence (vertex). 1 pair of frontal setae. Ocellar tubercle projecting only slightly above vertex, with 2 pairs of small ocellar setae. Postocular (occipital) region dark red-brown to black, but colour masked by strong silver pruinescence. Occiput with short, pale yellow-white macrosetae dorsally, short white macrosetae laterally and many fine, shiny white setae ventrally. Palpi dark red-brown, small, 2-segmented, fine pale yellow setose. Proboscis straight, tubular, dark red-brown to black, weakly fine white setose.

Thorax: Dark red-brown to black, but colour masked by silver and silver-gold pruinescence, pale yellow and fine white setose. Pronotum dark red-brown, silver pruinose, white setose. Mesonotum dark red-brown to black, entirely silver to silver-gold pruinose, fine white setose except for moderately well developed, pale yellow-white lateral macrosetae (2 npl, 1 spal, 2 pal). Scutellum dark red-brown, entirely silver pruinose, asetose except for 1 pair apical macrosetae. Pleura dark red-brown to black, but entirely strongly silver pruinose, almost asetose except for c. 5 white katatergal macrosetae. Anepisternal setae absent. Anatergites uniformly strongly gold pruinose, asetose.

Legs: Coxae red-brown, strongly silver pruinose, white setose; metathoracic coxae with small bulbous protuberance on anterior surface. Femora red-brown with orange distal and proximal ends, white setose. Tibiae and tarsi orange, terminal parts red-brown, white setose. Claws black with brown-orange basal parts, shorter than terminal tarsomere, gently curved. Empodium orange, straight, slightly shorter than claws. Pulvilli pale yellow, longer than empodium. Wings (Fig. 19) length measured from humeral crossvein to tip, breadth at widest level: Holotype 1.3 × 0.4 mm, paratypes – male (1) 1.4 × 0.5 mm, females (2) both 1.7 × 0.6 mm. Venation: C extends around wing margin terminating at junction of CuA+CuP, although it appears to extend weakly around at least part of cell cup. Alula reduced to a small lobe. All peripheral cells open except for m3 and cua which are closed and stalked. Little variation is evident. Veins mostly dark red-brown except proximally where veins are yellowish, membrane unstained, transparent, much of surface, especially distally, microtrichose.

Abdomen: Entirely dark red-brown, moderately fine gold-silver pruinose, short white setose (T1 with longer setae laterally and along entire posterior margin). ♂ tergites and sternites entirely pruinose, including epandrium which is covered with long shiny white setae. Fused gonocoxites and other visible parts of genitalia shiny apruinose. ♀ with segments 1–6 entirely pruinose, segments 7–9 shiny apruinose. ♂ terminalia (Figs 15–17): Epandrium completely divided medially into two epandrial lobes that closely abut at about 1/3 of their length (Fig. 16); distal tips of lobes broadly truncate terminally (dorsal and lateral views). Proctiger short, projecting distally for a short distance beyond epandrial lobes. Hypandrium wanting, or entirely fused with gonocoxite to form a large component of the terminalia. Fused gonocoxite with a broadly rounded mediodistal lobe best appreciated in ventral view (Fig. 17). Gonostyli dorsoventrally compressed, extending well beyond level achieved by gonocoxites and epandrium. Aedeagus largely hidden amongst other structures, robust, broad in lateral view with distal bifurcated tip. ♀ terminalia (Fig. 18): Ovipositor tubular, approximately as long as deep in lateral view; acanthophorite plates each bearing 5 stout, articulated ‘spines’; three equally large spermathecae, reservoirs tubular (not distinguishable from spermathecal ducts) and unsclerotized; genital fork (furca, S9) divided into two lateral sclerites, without any furcal apodeme.

Holotype

SOUTH AFRICA: ♂ holotype, ‘South Africa: N Cape / Tierberg Nature Reserve / 28°43.012'S, 020°59.805'E / 850m J Londt & T Dikow / 5.ii.2004, sparsely / vegetated exposed hillside’ (NMSA).

Paratypes

3♂ 3♀, same data as holotype (NMSA); 1♂ 1♀, same data (USNMENT01288302USNMENT01288303, USNM).

Distribution, phenology and biology

Known only from the type locality. Collected in February (Table 1). Little is known of the biology. Tierberg Nature Reserve is a small conservation area comprised almost entirely of a large rocky hill on the outskirts of Keimoes, a small town located on the north banks of the Gariep (= Orange) River which provides water for agricultural activities in what is otherwise an arid area of the country. Vegetation is sparse and dominated by succulents such as aloes (Figs 13–14). The flies were found resting on hard-baked ground and stones.

Figures 10–14.

Photographs of Trichoura pardeos sp. n. (paratype USNMENT01115152) and habitat: 10 dorsal (Morphbank #860646) 11 lateral (#860648) 12 head anterior (#860650) 13–14 rocky hill habitat at type locality at Tierberg Nature Reserve, Keimoes, Northern Cape, South Africa (28°43'01"S 020°59'48"E). Habitat photographs by T. Dikow. Scale bars: 1 mm.

Figures 15–19.

Male and female terminalia and wing of Trichoura pardeos sp. n.: 15 male, lateral 16 male, dorsal 17 male, ventral; 18 female lateral 19 wing. Scale bars: 1 mm.

Phenology of Trichoura species. Months commencing from July.

Species J A S O N D J F M A M J
T. krugeri
T. mesochora
T. pardeos
T. proctomeces
T. tankwa
T. torynopoda
T. tyligma

Discussion

All previously described Trichoura species have been registered in ZooBank and are listed below with their globally unique identifier, distributional records from Londt (1994) with updated geographic coordinates, and new material that has become available.

Trichoura krugeri Londt, 1994

http://zoobank.org/9CD32242-681F-425A-8BE5-9B45A0AD83EF

Fig. 20

South Africa: Mpumalanga Province: Kruger Park, Timbetene Tswiri waterholes, near Skukuza (c. 24°59'40"S, 031°35'40"E c. 290m).

Figure 20.

Map of South Africa with elevational relief and distribution of Trichoura species. (SimpleMappr 6129 - http://www.simplemappr.net/map/6129)

Trichoura mesochora Londt, 1994

http://zoobank.org/9C8BEFAC-5D2C-4A79-8581-7BFE0FB42342

Fig. 20

South Africa: Free State Province: 30 km E Boshof (c. 28°35'51"S 025°31'35"E c. 1295m); Krugersdrift Dam (c. 28°52'42"S, 025°57'13"E c. 1245m); Northern Cape Province: 35 km W Kimberley (c. 28°43'11"S, 024°24'10"E c. 1125m).

Trichoura proctomeces Londt, 1994

http://zoobank.org/D5A4DBFE-D6E5-45F4-8D97-DD58C51C5477

Fig. 20

South Africa: Western Cape Province: Knersvlakte north Vanrhynsdorp (c. 31°34'57"S, 18°43'40"E c. 125m); Knersvlakte (c. 31°35'15"S, 18°29'15"E c. 105m).

Trichoura tankwa Londt, 1994

http://zoobank.org/D41CAC5A-77E7-4BFE-BE54-B31D365A5664

Figs 1–3, 7–8, 20

South Africa: Northern Cape Province: Tankwa Karoo, Waterval (c. 32°21'00"S, 20°10'48"E c. 530m); 12 km S Calvinia (31°34'10"S, 19°43'56"E 1080m).

New records are available for this species that extend the distribution considerably:

5♂ 2♀, ‘Sth Africa: N Cape / 12km S of Calvinia / 31°34'10"S, 19°43'56"E / 7.ix.2002 J.G.H. Londt / 1080m Sandy roadside’ (NMSA); 3♂ 3♀ ‘South Africa: Western Cape: De Zeekoe Guest Farm, 33°37'26"S, 022°08'39"E, 294 m, 2015-12-07 collected p.m. (noon–15:00), Little Karoo veld, perching on low vegetation, Dikow, T.’ (USNMENT01115257, USNMENT01115051USNMENT01115152, USNMENT01136084USNMENT01136085, USNMENT01115175, USNM).

Trichoura torynopoda Londt, 1994

http://zoobank.org/38285701-CAFE-43AF-AF8F-1AD9C90369BD

Figs 4–6, 20

South Africa: North West Province: Bloemhof (c. 27°39'S 25°36'E c. 1235m); Gauteng Province: Pretoria, Waterkloof (c. 25°46'45"S 028°14'41"E c. 1440m).

New records from the same collecting event on which the species was based are available.

4♂, ‘Pretoria / Waterkloof / xii.15 / H.K. Munro’ (USNMENT01295405USNMENT01295408, USNM).

Trichoura tyligma Londt, 1994 (Fig. 20)

http://zoobank.org/8B8DD175-D35D-428C-9D76-144F9BF5DA08

South Africa: Northern Cape Province: 1 km N Kuboes (28°26'32"S, 16°59'32"E 210m).

Key to species of Trichoura

1 Dorsocentral macrosetae extend anteriorly to transverse suture (Fig. 2); ♂ epandrium with few erect setae that do not mask the shape of distal region of lobes 2
Dorsocentral macrosetae limited to area posterior to transverse suture (Fig. 6); ♂ epandrium with many shiny white, prone setae that tend to mask the shape of distal region of lobes 4
2 ♂ proctiger short, bulbous and truncate in lateral view; ♀ unknown T. tyligma
♂ proctiger elongate, evenly tapering in lateral view 3
3 ♂ proctiger shorter than epandrial lobes and projecting posteriorly; ♀ known T. tankwa
♂ proctiger longer than epandrial lobes and ventrally directed; ♀ unknown T. proctomeces
4 ♂ antenna unicolorous; metathoracic tarsomeres 2 and 3 each with a pair of dark red-brown leaf-like setae (Fig. 6) T. torynopoda
♂ antennal scape and pedicel paler in colour than postpedicel; metathoracic tarsomeres of more usual development (e.g., Fig. 2) 5
5 Fused gonocoxites of ♂ bilobed distally (best seen in ventral view) 6
Fused gonocoxites of ♂ with a single broadly rounded mediodistal lobe T. pardeos sp. n.
6 Epandrial lobes of ♂ elongate, pointed in lateral view, projecting beyond all other elements of terminalia T. krugeri
Epandrial lobes of ♂ short, broadly rounded in lateral view, not projecting beyond proctiger and gonostyli T. mesochora

Relationships

Artigas and Papavero (1991) established Willistoninini within their Stenopogoninae primarily based on the narrow face and diverging vertex and included a single genus, Willistonina Back, 1909, in it. This monotypic genus is distributed in the western Nearctic Region from British Columbia (Canada) in the north to Baja California (Mexico) in the south (E.M. Fisher pers. comm.). Dikow (2009a) included Willistonina bilineata (Williston, 1883) in a morphological phylogenetic study of Asilidae and the species, along with Ablautus coquilletti Wilcox, 1935, Sporadothrix gracilis Hermann, 1907 (included as Acnephalum cylindricum), Sisyrnodytes dasykylon Londt, 2009 (as Sisyrnodytes sp. (Gamka)), and Trichoura pardeos sp. n. (as Trichoura sp. (Tierberg)), did not group within Stenopogoninae in the cladogram, but in a distinct position. This fact along with the establishment of a new, phylogenetic classification for assassin flies warranted the recognition as a separate subfamily Willistonininae. This subfamily immediately sparked interest as it included western Nearctic (Ablautus and Willistonina) and southern Afrotropical (Sisyrnodytes, Sporadothrix, and Trichoura) genera. Sisyrnodytes is the only widespread Afrotropical genus that also penetrates the south-western Palaearctic Region (Londt 2009) while the other genera are confined to southern Africa. With the exception of Sisyrnodytes dasykylon, all then recognised Willistonininae were included in a molecular phylogenetic study by Dikow (2009b) where the subfamily was not recovered as monophyletic. However, these results were most likely caused by a reduced taxon sampling and the inclusion of only five nuclear genes (Dikow 2009b).

Willistonininae can be delimited by these synapomorphies: only lower facial margin of face slightly developed, prosternum and proepisternum separated and prosternum triangular and pointed dorsally, discal scutellar setae absent, setae on legs dorsoventrally flattened (also regular, circular setae present).

The phylogenetic classification proposed by Dikow (2009a) placed Trichoura as sister taxon to Willistonina based on the following morphological synapomorphies: mystax restricted to lower facial margin, mystacal setae tightly packed, frons markedly and suddenly diverging laterally, macrosetae present on lateral margin of frons, propresternum arrow-like, anterior surface of metathoracic coxa with blunt protuberance, and alula reduced to small lobe. This combination of characters is not found in any other assassin-fly taxon and therefore strong evidence for a close phylogenetic relationship despite the disjunct distribution. These character states can also serve as delimitation of the Willistoninini.

Since the remaining genera included by Dikow (2009a) in Willistonininae and the ones newly placed in it (Londt and Dikow submitted, see key below) are morphologically quite dissimilar, a new tribe Sisyrnodytini is established here. This tribe with its type genus Sisyrnodytes includes five Afrotropical genera (Acnephalomyia Londt, 2010, Ammodaimon Londt, 1985, Astiptomyia Londt, 2010, Sisyrnodytes, and Sporadothrix) and one western Nearctic genus (Ablautus) and is chiefly diagnosed by the absence of pulvilli. While no new phylogenetic analysis of the expanded Willistonininae is presented here, we postulate the monophyly of the two tribes.

Willistonininae has its generic diversity in southern Africa with six genera occurring in and four endemic to the area. The western Nearctic has only two genera but a relatively high species diversity as Ablautus currently has 13 known species and a revision of the genus is underway with the description of some 11 new species (Herbert and Dikow in prep.).

Key to genera of Willistonininae

The following key, modified from Londt and Dikow (submitted) to incorporate the Nearctic genera, may be useful in separating the eight Willistonininae genera.

1 Pulvilli well-developed (Fig. 34, Willistoninini) 2
Pulvilli minute or absent (Fig. 32, Sisyrnodytini) 3
2 Wing with cell m3 closed and stalked (Fig. 19); vein C extends strongly around wing margin until it reaches confluence of CuA+CuP when it appears to terminate or proceed very weakly around cup and alula (Fig. 19); ♂ hypandrium absent or fused with gonocoxites to form a single cup-shaped entity; Afrotropical Trichoura
Cell m3 open at margin, even if only narrowly (Fig. 33); vein C extends strongly around entire wing margin including cup and alula (Fig. 33); ♂ hypandrium well developed and separated from gonocoxites; Nearctic Willistonina
3 Vein C extends strongly around entire wing margin including cup and alula; Nearctic Ablautus
Vein C does not extend around entire wing margin 4
4 Abdomen cylindrical, not obviously dorsoventrally flattened (width : length ratio of tg2 < 1.5, Fig. 31) 5
Abdomen broad and obviously dorsoventrally flattened (width : length ratio of tg2 > 2, Fig. 23) 6
5 Small flies (wing length < 3.5 mm, Figs 25–26); empodium absent; supernumerary crossvein (R3) absent on R4; scutal macrosetae well-developed, many times longer than accompanying setae; Afrotropical Ammodaimon
Larger flies (wing length > 6.0 mm, Figs 31–32); empodium well-developed; supernumerary crossvein (R3) developed as short stump-vein on R4 (Fig. 31); scutal macrosetae moderately developed, not many times as long as accompanying setae; Afrotropical Sporadothrix
6 Vein C terminating before reaching CuA+CuP (Fig. 29); cell r5 closed and stalked (stalk frequently failing to reach wing margin, Fig. 29); Afrotropical, Palaearctic Sisyrnodytes
Vein C terminating at point where CuA+CuP reaches wing margin (Fig. 23); cell r5 open (Fig. 23) 7
7 Cell m3 open (Fig. 23); supernumerary crossvein (R3) developed as short stump-vein on R4 (Fig. 23); pulvilli poorly developed, but clearly discernible (Fig. 24); male hypandrium somewhat flat or only gently concave; Afrotropical Acnephalomyia
Cell m3 closed and stalked; supernumerary crossvein (R3) absent on R4; pulvilli minute, difficult to detect (Fig. 28); male hypandrium distinctly cup-shaped; Afrotropical Astiptomyia
Figures 21–26.

Photographs of Willistonininae: 21 male Ablautus sp. (AAM-004314), dorsal (Morphbank #860664) 22 same, lateral (#860666) 23 male Acnephalomyia sp. (USNMENT01115145), dorsal (#860685) 24 same, lateral (#860687) 25 female Ammodaimon sp. (USNMENT00995300), dorsal (#860693) 26 same, lateral (#860695). Scale bars: 5 mm.

Figures 27–30.

Photographs of Willistonininae: 27 female Astiptomyia bikos Londt, 2010 (NMSA-DIP-66454), dorsal (Morphbank #860701) 28 same, lateral (#860704) 29 female Sisyrnodytes subater Oldroyd, 1957 (USNMENT00870084), dorsal (#860710) 30 same, lateral (#860712). Scale bars: 5 mm.

Figures 31–34.

Photographs of Willistonininae: 31 male Sporadothrix gracilis Hermann, 1907 (USNMENT00870183), dorsal (Morphbank #860718) 32 same, lateral (#860720) 33 male Willistonina bilineata (Williston, 1883) (UCRCENT80299), dorsal (#860726) 34 same, lateral (#860728). Scale bars: 5 mm.

Phenology and distribution

The phenology of species is summarised in Table 1. Species are active between September and March. As expected, the three species found in winter rainfall areas (T. proctomeces, T. tankwa, T. tyligma) are active in Spring (September to November) while those occurring in summer rainfall areas are active during summer and autumn (December to March). T. tankwa has been collected in both November and December.

The distribution of Trichoura species is shown in Fig. 20. It is interesting to note that all species are currently confined to a band running across South Africa from summer rainfall areas in the north-east down to winter rainfall areas in the south-west of the country. Those found in the winter rainfall region (T. proctomeces, T. tankwa, T. tyligma) possess well developed dorsocentral macrosetae anterior to the transverse suture, while the other four species (T. krugeri, T. mesochora, T. pardeos, T. torynopoda) lack these setae. This may be suggestive of two distinct groups. It is highly likely that the genus will eventually be found in Namibia, Botswana, Mozambique and possibly Zimbabwe.

Acknowledgements

The senior author wishes to thank the University of KwaZulu-Natal and the National Research Foundation (NRF) of South Africa for allocating funding in support of his research. The KwaZulu-Natal Museum provided various services while his wife, Ann, continued to provide assistance and support. The junior author acknowledges field work support by the Global Genome Initiative (GGI) at the Smithsonian Institution to visit the Nama and Klein Karoo in December 2015. The team at the De Zeekoe Guest Farm and in particular Dolf Grobler and J.D. Glinister are thanked for allowing collecting and accompanying the junior author in the field. Karie Darrow and Meg Gisonda are thanked for assistance in photographing specimens. Rodrigo Vieira and Aubrey Scarbrough are thanked for comments that improved the manuscript during peer review. The assistance of the conservation authorities issuing collecting permits in the Northern Cape and Western Cape Provinces is appreciated.

References

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