A Review of Afrotropical Sisyrnodytes Loew, 1856 (Diptera: Asilidae: Stenopogoninae)

ABSTRACT The genus Sisyrnodytes Loew, 1856 is reviewed and the Afrotropical species revised. A key for the separation of species is presented and the fauna is discussed with respect to available distributional and biological data. The following Afrotropical species are described as new: aethes (South Africa), ausensis (Namibia), dasykylon (South Africa, Namibia), oligotrichus (Namibia), xeromyia (Botswana, Namibia). The following previously described Afrotropical species are considered valid: apicalis Oldroyd, 1957; aterrimus Engel, 1929; brevis (Macquart, 1838); curtus (Wiedemann, 1819); irwini Oldroyd, 1974; major Adams, 1905;nilicola(Rondani, 1850); niveipilosus Ricardo, 1925; subater Oldroyd, 1957; vestitus Oldroyd, 1974. The following new synonymies are established: S. defusus Oldroyd, 1974 and S. diplocus Oldroyd, 1974 = S. brevis; S. luscinius (Walker, 1849) = S. curtus; S. erebus Oldroyd, 1957 = S. major. A neotype is designated for S. brevis (Macquart, 1838), and lectotypes are designated for S. major; S. floccus Loew, 1856; S. niveipilosus. One species has been removed from Sisyrnodytes: Acnephalum sericeus (Oldroyd, 1974), comb. n.


INTRODUCTION
Members of the asilid genus Sisyrnodytes Loew, 1856 are small to medium-sized flies. Their somewhat dorsoventrally compressed, broad bodies give them a bee-like appearance (Figs 1, 2). Many species inhabit dry, sandy or rocky terrain where they usually perch on stones or on open sandy ground. Very little is known about their biology. Species of Sisyrnodytes have frequently been confused with those of Acnephalum Macquart, 1838, and this confusion, coupled with the fact that many unidentified specimens were to be found in southern African natural heritage institutions, prompted this study. Much of the taxonomic confusion that has characterised these two genera has been a consequence of two main factors. Firstly the reduction in size of the terminal abdominal segments and consequential concealment of the terminalia, coupled with the frequent presence of long setae, makes the study of genitalia difficult (this certainly accounts for the many incorrectly sexed specimens encountered in this study). Secondly, considerable morphological variation exists. This variation is evident in both individuals belonging to any single local population as well as between populations over geographical ranges. In addition there is variation in the form of sexual dimorphism.
As in many other asilid genera, the adequate diagnosis of species is heavily reliant on an appreciation of the morphology of male genitalia. Unfortunately some previous studies have been undertaken without the benefit of information derived from a careful study of genitalia. While this study has incorporated information derived from male genitalia, the identification of some specimens may still be in doubt as it is impractical to dissect and macerate the terminalia of every specimen. Fortunately the shape of the hypandrium is a useful mean of separating species, and in most instances it is possible to see this Hull (1962) -In his world review of asilid genera provided a detailed description and listed the following species: Palaearctic: brevis (with contrarius, floccus and nilicola as synonyms), leucophaetus and rufus. Ethiopian (= Afrotropical): aterrimus, curtus, disjunctus, major, niger and niveipilosus, providing illustrations of brevis and niveipilosus.  -In reviewing the southern African asilid fauna he briefly discussed Sisyrnodytes providing a key to 13 species, including eight previously described species (apicalis, aterrimus, brevis, curtus, luscinius, major, niveipilosus, subater) and five new ones (defusus, diplocus, irwini, sericeus, vestitus).
At the commencement of this study there were therefore 15 Afrotropical species (i.e. those catalogued by Oldroyd (1980)), and four Palaearctic species (i.e. the three catalogued by Lehr (1988) and engeddensis Theodor, 1980, that was somehow overlooked by Lehr). Two of the species (brevis (Macquart, 1838) and nilicola (Rondani, 1850)), have been listed for both regions, which means that there were 17 valid species names at the start of this review. With the description of five new species, the synonymy of four established names, and the transfer of one species to Acnephalum, the number of Afrotropical species remains at 15.

Specimens
Material used in this study is housed in the institutions listed below. The abbreviations supplied are used when listing specimens. The curators that kindly assisted me are named in brackets following the name of the respective institution.

Label data
A standard format has been employed when recording label information. As material is not abundant all label data is reproduced as it appears on labels. For multiple labels each label is demarcated by the use of single inverted commas while each line of data is separated by a spaced slash ( / ). Data that appear on the reverse side of a label are preceded by a '~' symbol. In some instances the colour of a label is given in square brackets. In instances where a series of specimens have identical label data, except for the date of collection, repetition is avoided by merely listing the dates and indicating the number of specimens involved. Square brackets are used when useful information or comment not found on labels is deemed necessary. In this regard, coordinates are usually provided when these, or a quarter-degree grid reference, do not appear on labels. Because of the difficulty of establishing exactly where some localities are (e.g. 146 km E. Swakopmund), coordinates provided in brackets are for the named place preceding the provision of this additional information. The use of question marks usually indicates unknown or questionable information. Specimens are arranged in geographical order according to latitude and within countries (alphabetically ordered).

Descriptive passages
Morphological terminology usually follows McAlpine (1981). A brief generic diagnosis is provided. If a fuller description is required, that of Hull (1962) can be consulted. Species descriptions are brief and confined largely to characteristics that are considered helpful in the separation of species. As there is significant variation in coloration, colours provided should be interpreted with some latitude.
It should be noted that in order to adequately view and study the retracted male genitalia, these need to be excised, softened through maceration and physically extruded. This was done by inserting a pin into the opening created when the terminalia were excised with fine scissors. The genitalia were effectively exposed by carefully positioning the point of a pin and dragging the terminalia over it. On occasion the pin point was inserted into the basal part of the aedeagus and this explains why this organ is sometimes illustrated in an almost completely extruded position. Unfortunately, this method of extrusion may cause some soft, macerated sclerites and associated membranes to buckle (e.g. the highly reduced weakly sclerotised epandrium). However, most of the organs providing good diagnostic characters (e.g. the hypandrium and gonocoxites) are usually not adversely affected.
Final illustrations were prepared from pencil drawings without employing any graphic software for their manipulation and do not depict setae as these are not considered to have any great diagnostic value. Measurements were taken as follows: Eye and face widths were measured viewing the head anteriorly and at the level of greatest width. Wing length is from humeral crossvein to tip, while breadth is measured at the broadest level of the wing. TAXONOMY Genus Sisyrnodytes Loew, 1856 Sisyrnodytes: Loew 1856: 40. Type species: Sisyrnodytes floccus Loew, 1856 [= Acnephalum nilicola Rondani, 1850], by monotypy.
Diagnosis: A distinctive bee-like member of the subfamily Stenopogoninae. Characterised by the possession of asetose anatergites, minute or no pulvilli, and a costal vein that usually terminates before the wing tip (Figs 3,4). A single species has the costal vein extending beyond the wing tip and terminating where M 2 reaches the wing margin (Fig. 5). In addition the wing membrane lacks microtrichiae entirely and, as a consequence of the shortened costal vein, veins R 4 +M 1 , M 2 , M 3 +CuA 1 and CuA 2 +A 1 frequently fail to reach the wing margin (Figs 3, 4). Male genitalia are withdrawn between distal terga and sterna, while the epandrium is invariably small and poorly developed.
Sisyrnodytes aethes sp. n. Figs 5-7, 44 Etymology: From Greek aethes (unusual, strange). Refers to the unusual wing venation that represents a condition intermediate between that found in Acnephalum and that characteristic of all other species of Sisyrnodytes. Description: Male. Head: Dark red-brown to black with yellow, white and pale orange setae. Antennae: Orange except for slightly paler tip of style. Scape and pedicel pale yellow-white setose. Major ventral setae of pedicel project beyond level achieved by postpedicel. Basal element of style long (twice as long as broad). Eye to face width ratio 2.7:1. Mystax moderately long, yellow-white. Frons and vertex yellow-white setose. Laterally situated frontal setae not extending below antennal sockets. Occipital setae white, postoculars orange dorsally. Palps and proboscis dark red-brown, white setose. Thorax: Dark red-brown to black. Pronotum white, pale yellow and orange setose. Mesonotum entirely pale yellow setose, but asetose centrally (probably through abrasion). Scutellum apruinose with poorly defined transverse groove; disc asetose, apical setae numerous (difficult to count) pale yellowish. Pleural setae long, glistening whitish. Katepimeron strongly setose, katatergals long, shafts more or less smooth (i.e. not wavy). Legs: Orange, mainly white and pale yellow setose (there are some dark red-brown to black setae distally on tibiae and ventrally on tarsi). Claws longish, dark red-brown to black; empodia short yellowish; pulvilli minute to absent. Wings c. 7.8 (tip missing) × 3.5 mm; C white setose basally; membrane transparent but slightly pale yellowish stained anterobasally. Venation unusual with C not terminating at the wing tip but continues around it, ending slightly beyond where M 2 reaches wing margin (as in Fig. 5). In addition veins M 3 +CuA 1 and CuA 2 +A 1 reach wing margin. Haltere brown-yellow with reddish knob. Abdomen: Dark red-brown, glistening white setose; setae long laterally and along posterior margins of terga.
Genitalia (Figs 6, 7): Epandrium greatly reduced and simple in structure, proctiger extending well beyond it. Gonocoxite with external lobe tapering to blunt tip, internal lobe with slightly inflated distal tip. Gonostylus shorter than internal lobe of gonocoxite and simple in structure. Hypandrium flattish, triangular in ventral view, with medial lobe extending almost as far as tip of internal lobe of gonocoxite. Aedeagus fairly slender with small, blunt tip. Female: Agrees with male except as follows. Generally more yellow and orange setose. Prothorax mostly orange setose; mesonotum anteriorly orange and posteriorly yellow setose. Apical scutellar setae not as numerous (c. 30). Legs orange-brown. Wing (Fig. 5) length 6.6 mm; venation as in male, but C ends where M 2 reaches wing margin (not slightly beyond that point as in male). Abdominal setae shorter. Distribution, phenology and biology: Recorded only from two fairly widely separated localities in the winter-rainfall region of South Africa (Fig. 44). Adults active in November and December (Table 1). The female paratype was collected on sandy ground near a stream flowing through the Meiringspoort and was found together with brevis.
Similar species: This is a distinctive species, differing from congeners in having costal vein continuing around wing tip and terminating where M 2 reaches wing margin.

Redescription:
Male (based on holotype in excellent condition; left prothoracic tarsus, left mesothoracic tarsomere 5, and terminal part of right prothoracic tarsomere 5 broken off). Head: Dark red-brown to black, with black, white and pale brownish setae. Antennae: Dark brown except for tip of style which is yellowish. Scape and pedicel mostly black setose (a few pale brown setae dorsally on pedicel). Major ventral setae of pedicel project beyond level achieved by postpedicel. Basal element of style short (slightly longer than broad). Eye to face width ratio 2.5:1. Mystax shortish, black except for small group of white setae dorsally. Frons and vertex white setose except for c. 4 long black ocellar setae. Laterally situated frontal setae not extending below antennal sockets. Occipital setae mostly black, postoculars mixed white and yellowish. Palps and proboscis black setose (tip of proboscis has white setae). Thorax: Dark red-brown to black. Pronotum white, brown and dark red-brown setose. Mesonotum entirely setose except for narrow paramedial strips, sutural and postsutural spots. Lateral macrosetae black, other setae mostly mixed white and pale brownish orange, but there are small clusters of uniformly white or black setae situated mainly anteriorly. Scutellum apruinose with poorly defined transverse groove (has a crinkled appearance); disc asetose, apical setae numerous black, yellowish and white (black setae constitute a posterior row, are best developed and number c. 40). Pleural setae mostly black except for some white and yellowish setae dorsally on anepisternum. Katepimeron black setose, katatergals black, long, shafts more or less smooth. Legs: Dark red-brown, mainly black setose (there are some small white and yellowish setae on pro-and mesothoracic legs). Claws longish, dark red-brown; empodia short yellowish (most appear broken); pulvilli minute to absent. Wings 5.9×2.5 mm; C white setose basally; membrane pale brownish stained except for distal third of wing. Haltere dark red-brown.
Abdomen: Dark red-brown, black setose except for posterior parts of T1-3 which are mostly white setose. Genitalia: Not dissected, but visible structures appear to conform to dissected and illustrated genitalia of a male from Strandforntein (Figs 8,9). Epandrium greatly reduced and simple in structure, proctiger (cerci) extending well beyond it. Gonocoxite with external lobe tapering to obliquely pointed tip, internal lobe dorsoventrally compressed. Gonostylus longer than internal lobe of gonocoxite, slender and with curved distal end. Hypandrium flattish, triangular in ventral view, with medial lobe extending as far as tip of internal lobe of gonocoxite and with a broadly rounded distal end. Aedeagus fairly robust with an obliquely pointed tip. Female: Similar to male, but have more white setae (for example, antennal setae mixed white, dark red-brown and pale brown; mystax more extensively white in dorsal region; ocellar setae white; pleural setae more extensively white; legs more extensively white setose). Variation: Wing length 4.6-6.6 mm. The male from Strandfontein (near type locality) agrees well with the holotype as does the Namibian male, although there are small differences in the latter (e.g. some mesonotal macrosetae (spal & pal) are pale yellowish). Distribution, phenology and biology: Recorded from two localities on the sandy 'Cape Flats' near Cape Town, Milnerton (type locality) and Strandfontein, but also recorded some distance away from Swakopmund (Namibia) (Fig. 42). Collected in February, March and April (Table 1). While no ecological data is recorded on labels localities have sandy coastal dunes in common and so it is likely that the species inhabits this environment. Similar species: This species is similar to aterrimus, major and vestitus.

Redescription:
Male (based on holotype in excellent condition, slightly dusty). Head: Dark red-brown to blackish, blackish setose. Antennae: Dark orange-brown except for tip of style which is pale yellowish. Scape and pedicel blackish setose. Major ventral setae of pedicel shortish, failing to project beyond level achieved by postpedicel. Basal element of style short (shorter than broad). Eye to face width ratio 2.5:1. Mystax shortish, black. Frons and vertex blackish setose. Laterally situated frontal setae not extending below antennal sockets. Occipital and postocular setae blackish. Palps and proboscis black setose.
Thorax: Dark red-brown to black. Pronotum black setose. Mesonotum entirely black setose except for few white setae corresponding in position to anterior acrostichals and asetose narrow paramedial strips, sutural and postsutural spots. Scutellum apruinose with poorly defined transverse groove (has crinkled appearance), disc asetose, apical setae blackish, difficult to count (c. 20). Pleural setae dark red-brown to black, katatergals long, shafts more or less smooth. Legs: Red-brown, black setose. Claws blackish; empodia short yellowish, pulvilli minute to absent. Wings 3.7×1.5 mm, C black setose basally; membrane transparent. Haltere dark red-brown. Abdomen: Dark red-brown, blackish setose, setae generally tiny except along lateral margins of terga. Genitalia: Not dissected, but visible structures appear to conform to dissected and illustrated genitalia of the paratype _ (Figs 10-12). Epandrium greatly reduced and simple in structure, proctiger extending well beyond it. Gonocoxite with external lobe tapering to blunt tip and with ventral flange, internal lobe with forked distal end. Gonostylus slender, distinctly curved subapically, projecting beyond level attained by internal lobe of gonocoxite. Hypandrium flattish, almost oval in ventral view, proximal end only slightly broader than distal end. Aedeagus fairly robust with blunt tip. Female: Similar to males except wings are weakly stained basally. Staining extends along most of the veins. Variation: Wing length _ 3.7-5.3 mm, ^3.4-6.1 mm. The fairly large sample from Zomba was measured (except for 2_ 1^with wings missing) to give an indication of size range at a single locality: _ 3.8-5.3 mm (x -=4.4 mm, n=16), ^4.2-6.1 mm (x -=5.0 mm, n=8). Females on average bigger than males. The holotype is more extensively blackish setose when compared with all other males. Most males have some white setae in the following places -dorsal part of mystax, frons and vertex, postocular region, prothorax, anterior and lateral (few) parts of mesonotum, posterior margins of T1-3 mediolaterally (not medially or laterally but in-between). Sexual dimorphism in setal coloration is strongly evident in as much as the entire head, in males (except for palpi and proboscis) is white setose, prothorax is mostly white and yellow setose (few dark red-brown setae), mesonotum extensively yellow and white setose (except for a few dark red-brown setae), legs extensively white setose except for macrosetae which are blackish, all abdominal terga have white setose posterior margins.  (NMSA). Notes: The holotype is double mounted on a strip of card and a little green verdigris is present above and below the specimen. Engel (1929) called the two _ specimens studied by him the 'type and cotype' respectively. As one of the specimens carries an old orange 'type' label I accept this specimen as the holotype; the other must therefore be considered a paratype. While the types were originally deposited in the Transvaal Museum, Pretoria, their Diptera collection was transferred in its entirety to the Natal Museum during the early 1970s. Distribution, phenology and biology: Recorded from Malawi, Zambia and Zimbabwe (Fig. 40). This distribution overlaps with that of major, but as of yet the species have not been recorded together at the same locality. Adults are active from June through September (Table 1), as cited by , although one record exists for April (this may be an error in labelling-perhaps 'iv' should read 'vi'). The species therefore flies during winter. Biological data are minimal -one label states that the specimen was collected in flowers of the sausage tree (Kigelia africana) and was found in the company of bees of the genus Trigona. The significance of this observation is unknown. Some specimens were collected on rocky pathways. One female from Zomba is pinned with a heteropteran of the family Lygaeidae. Similar species: This species is similar to apicalis, major and vestitus.

Sisyrnodytes ausensis sp. n. Figs 13, 14, 41
Sisyrnodytes brevis (misidentification of material from Aus) : Oldroyd 1957: 84;1974: 73. Etymology: The name is derived from the type locality of Aus. Description: Male (based on holotype in good condition). Head: Dark red-brown to black, white setose. Antennae: Dark red brown except for distal half of postpedicel and tip of style which are pale brownish. Scape and pedicel white setose. Major ventral setae of pedicel do not project beyond level achieved by postpedicel (are broken). Basal element of style short (slightly longer than broad). Eye to face width ratio 1.7:1. Mystax longish, white. Frons and vertex white setose. Laterally situated frontal setae extending below antennal sockets. Occipital and postocular setae white. Palps and proboscis dark red-brown, palpi dark red-brown setose, proboscis white setose. Thorax: Dark red-brown to black. Pronotum white setose. Mesonotum entirely setose except for narrow paramedial strips, sutural and postsutural spots. Lateral macrosetae white (npl) and yellow (spal & pal); other setae white (anteriorly) and glistening yellowish (posteriorly). Scutellum apruinose with poorly defined transverse groove (has a crinkled appearance); disc asetose, c. 20 yellow apical setae. Pleural setae white and yellowish. Anepisternum white setose, katepimeron asetose, katatergals pale yellow, long, shafts more or less smooth. Legs: Dark red-brown, mainly white setose (there are some black setae at distal tips of tibiae and ventrally on tarsi). Claws longish, dark redbrown; empodia short yellowish; pulvilli minute to absent. Wings 4.4×3.1 mm; C yellow setose basally; membrane transparent but brownish stained proximally (staining extends to end of costal cell and is weaker posteriorly). Haltere yellow with pale brown stalk. Abdomen: Dark red-brown, terga with tiny setae medially (appearing asetose), and moderately long white setose laterally, Sterna long wavy yellowish setose. Genitalia (Figs 13,14): Epandrium reduced and simple in structure, proctiger extending well beyond it. Gonocoxite with external lobe tapering to narrowly-rounded tip, internal lobe longish, with slightly bilobed distal end. Gonostylus slightly longer than internal lobe of gonocoxite and simple in structure. Hypandrium flattish, sub triangular in ventral view, narrowing a little before midlength, medial lobe with almost parallel sides extending well beyond outer lobe of gonocoxite, but falling short of the distance attained by internal lobe. Aedeagus fairly slender with small, blunt tip. (Note: The genitalia were attached to a card pinned under the specimen and appeared to have been cleared (probably by Oldroyd). This card was removed, placed in warm KOH (which caused the genitalia to become detached from the card) and stored in a vial containing an alcohol/glycerine mixture after being illustrated.) Female: Similar to male but slightly larger and have far more yellow to pale orange setae. One female has the head entirely yellowish setose except for some ventral occipitals; pronotum yellow-white setose; mesonotum entirely yellow setose; legs yellow setose except for the dark red-brown setae as in male; abdomen with yellow setae laterally (some extending along posterior margins of terga  ;Oldroyd 1974: 73;1980: 368 (catalogue). Sisyrnodytes defusus Oldroyd, 1974: 74;1980: 368 (catalogue). Syn. n. Sisyrnodytes diplocus Oldroyd, 1974: 74;1980: 368 (catalogue). Syn. n.

Redescription:
Male (in the absence of the brevis holotype, the description is based on the defusus holotype _ (now considered the neotype of brevis); condition: fair, left wing broken off at base and missing, right wing broken off just beyond humeral crossvein-all cells missing except for cell a1; mesonotum and scutellum appear somewhat abraded and a number of setae are missing; the specimen is double mounted on a strip of cellulose and pinned laterally). Head: Dark red-brown to black, setae white except for a few brownish orange postoculars. Antennae: Dark red brown except for tip of style which is yellowish. Scape and pedicel white setose. Major ventral setae of pedicel project to a similar level achieved by postpedicel. Basal element of style short (slightly longer than broad). Eye to face width ratio 2.0:1. Mystax shortish, white, weakly developed dorsally (leaving a shiny apruinose, asetose strip between the eyes below antennal sockets). Frons and vertex white setose. Laterally situated frontal setae not extending below antennal sockets. Occipital setae mostly white, postoculars brownish orange. Palps and proboscis white setose. Thorax: Dark red-brown to black, white setose. Prothorax white setose. Mesonotum entirely white setose (except for abraded areas). Scutellum apruinose with moderately defined transverse groove; disc asetose, c. 12-14 white apical setae in two groups (absent medially). Pleural setae white. Katepimeron asetose; katatergals long, white, shafts more or less smooth. Legs: Dark red-brown, mainly white setose except for few strong black setae at distal tips of tibiae and ventrally on tarsi. Claws longish, black; empodia longish, yellowish; pulvilli minute to absent. Wings broken off and missing (see information under variation). Haltere yellow-brown. Abdomen: Dark red-brown; white setose, but poorly so over medial parts of T1-5. T1-6 with longish, pale glistening white setae laterally especially in more distally situated segments.
Genitalia: Not dissected, but visible structures appear to conform to dissected and illustrated genitalia of a male from the Karoo Botanic Gardens, Worcester (Figs 15,16). Epandrium greatly reduced and simple in structure, proctiger extending well beyond it. Gonocoxite with external lobe tapering to fairly sharp tip, internal lobe robust, with characteristic shape in lateral view (a useful feature when viewing undissected males). Gonostylus somewhat shorter than internal lobe of gonocoxite and simple in structure. Hypandrium flattish, sub-triangular in ventral view, with long medial lobe extending beyond tip of external lobe of gonocoxite. Medial lobe, in ventral view, with lateral wing-like projections basally (there is some variation in the degree of development of these). Aedeagus slender with blunt tip. Female. Similar to male but commonly has more yellow and orange setation. Variation: A topotypic male specimen identified as defusus has wings measuring 3.5×1.5 mm. This is a fairly variable species; males are generally smaller than females with measured wing lengths of _ 2.6-3.7 mm, ^2.9-4.7 mm respectively. The defusus type, and other material from Worcester, are extensively white setose (except for some orange setae on occiput and prothoracic tibiae). Males from other localities may, however, be more extensively yellow or orange setose, the areas most commonly affected include the antennae, frons, occiput, pronotum, anterior parts of mesonotum and legs. Neotype designation: Although  states 'Holotype in Muséum national d'Histoire naturelle, Paris.', the specimen is unfortunately no longer there. In complying with the qualifying conditions for the designation of a neotype, I provide the following information as required by Article 75 of the International Code of Zoological Nomenclature (ICZN 1999: 84-85).
Clarification of taxonomic status: S. brevis, originally described from 'The Cape', is a long-established species that is now believed to be confined to South Africa. There has been considerable confusion surrounding its identity and various scientists have recorded it from localities north of the equator in both Palaearctic Africa and beyond. Although these records are now believed to relate to nilicola, this, and the other Palaearctic species, urgently need revision. There is therefore a need to clarify the status of the species and to provide some taxonomic stability. The designation of a neotype provides a standard reference specimen. Characters differentiating brevis from other species: The description provided, together with illustrations of the male terminalia and the key serve well to define this species and to separate it from all other Afrotropical species. Recognition of the neotype specimen: The specimen is clearly labelled as neotype.
Reasons for believing that the holotype is lost or destroyed: The holotype used to form part of the Macquart's collection housed in the MNHN. This was confirmed by the curator of this collection, Christophe Daugeron, who also informed me that the specimen is no longer in the collection and that there is no record of it having been sent to anyone on loan. In addition, a colleague, Prof. Denis Brothers, personally examined the relevant drawer and confirmed that the specimen is now missing.

Evidence of consistency with what is known about the holotype: Although Macquart's original description, in Latin and French, is brief, the neotype conforms well to it.
Evidence that the neotype comes from the same region as the holotype: Pierre Antoine Delalande (1787-1823) collected the material used by Macquart. While it is not possible to ascertain precisely where the material was found it is known that Delalande, who spent some time in Cape Town and the Algoa Bay area, made three journeys into the interior between November 1818 and September 1820. He could have collected the brevis type(s) on any of these trips. Although Worcester, about 100 km east of Cape Town, is the other side of a mountainous area, it is one of the closest localities to Cape Town from which brevis is positively recorded. Worcester is also the type locality of defusus, which is now considered a synonym of brevis. I therefore conclude that Worcester is an appropriate type locality. Repository of neotype: The neotype is housed in the BMNH, London as indicated below in the list of types studied. Distribution, phenology and biology: Although fairly widely distributed (Fig. 41), brevis is a South African endemic. All previous reports of the species from countries much further north are erroneous, referring mainly to nilicola which superficially resembles brevis.  reports the species from southern Namibia, but his material, from Aus, represents another species described earlier in this paper as ausensis. Adults are active during summer (October-February) ( Table 1) and inhabit both winter and summer rainfall regions. Label data indicate that dry, sandy and often rocky environments are favoured. Many specimens were found on rocky hillside slopes while others were collected in Acacia savannah areas. Personal experience suggests that individuals rest on exposed sand or rocks, darting after small insect prey flying close to the ground. There are three prey records in the Natal Museum database, all from Clifton Farm near Grahamstown. Two males were captured with Hymenoptera (Cynipidae) while one female was found feeding on a small Coleopteran (probably Chrysomelidae). Personal experience indicates that populations may on occasion be locally fairly high. Comments: It is clear that Oldroyd, who revised the genus in 1957 and again added to our knowledge in 1974, did not have a good concept of brevis. Evidence for this was gleaned from the following analysis.  (pal), other setae mostly white (there are a few pale brownish ones). Scutellum apruinose, somewhat inflated, with poorly defined transverse groove; disc asetose, 16 apical setae ranging from orange-brown (laterally) to yellowish (medially). Pleural setae white. Katepimeron asetose, katatergals long, shafts more or less smooth proximally, wavy distally. Legs: Red-brown, meso-and metathoracic femora orange anteroventrally, metathoracic tibiae mostly orange. Legs mainly white setose, but there are black setae terminally on tibiae and ventrally on tarsi. Claws longish, dark red-brown; empodia short yellowish, pulvilli moderately developed (longer than empodia and about one-third length of claws). Wings 5.2×2.2 mm, C white setose basally; membrane weakly pale orange stained basally. Haltere brown-yellow. Abdomen: Red-brown; terga partly yellow-white setose (these setae mainly laterally situated, but do extend along posterior margins for a short distance).
Male: Similar to female. Genitalia: The terminalia of a male from '7 mi. N. Vanrhynsdorp' were excised, macerated and illustrated (Figs 17,18). Epandrium reduced and simple in structure, about twice as long as broad in lateral view. Proctiger fairly short. Gonocoxite with suboval external lobe (in lateral view). Internal lobe fairly robust with small inwardly directed hooked tip. Gonostylus short, simple in structure. Hypandrium fairly robust, suboval in ventral view, constricted at about midlength (in ventral view). Aedeagus fairly robust, blunt tipped. Variation: Wing length _ 3.1-5.2 mm, ^3.1-6.2 mm. A fairly variable species with respect to general body and setal coloration. For example, antennae and mystax may be entirely white setose and occiput may lack yellowish macrosetae. Major ventral setae of pedicel usually extend beyond level attained by postpedicel. Leg coloration varies from orange through to dark red-brown, metathoracic legs often paler than others. Wing staining also varies slightly in both intensity and extent. Abdominal coloration variable from almost entirely orange (parts of T1 always dark red-brown) to almost entirely redbrown (lateral parts of terga invariably paler than medial parts).   states 'Holotype in Copenhagen Museum', but Thomas Pape (pers. comm.) reports that the species is not represented in that collection. The only specimen likely to be the type is the NHMW female even though Wiedemann (1821) indicated his material as being male. Other type material examined: SOUTH AFRICA: ^holotype (luscinius) 'Type' [circular with green rim], 'Dr. Smith. / S. Afr. 44-6.', 'One of Walkers / series so named. / E A W', 'Holotype / Dasypogon / luscinius Walker / det. J.E. Chainey. 1983' [this label has a circular red rimmed label glued to its upper right hand corner reading 'Holo-/ type'] (BMNH). Notes: The luscinius^holotype is double mounted on a cellulose strip. Condition: Poor, head detached and glued to mounting strip, both antennae broken off beyond pedicel. The thorax remains on its mounting pin but all the legs are broken off beyond trochanter; one, probably the right prothoracic leg, is glued to the mounting strip and is complete enough to show the condition of the pulvilli. The right wing is missing while the left wing is dirty and has somewhat ragged edges (approx. measurements are 5.0×2.0 mm). The abdomen is detached and glued to the mounting strip. The specimen is sufficiently well preserved to allow comparisons with other specimens. A well preserved female from 'Knersvlakte, North of Van Rhynsdorp' agrees very well with the holotype.
Type locality: I here designate the type locality as South Africa, Western Cape, Table  Mountain  Distribution, phenology and biology: This species is a South African endemic found in the winter-rainfall areas of the Western Cape Province (Fig. 43). Adults are active from spring to autumn (i.e. September-March (no February record)) ( Table 1). Label data indicate that the species is found predominantly in sandy places (e.g. vegetated dunes and similar situations) with fynbos vegetation. Personal experience suggests that individuals rest on open sand in places where there are plants to provide some shade and protection from wind, and that population levels may be locally fairly high. Similar species: This species is distinctive and not easily confused with others. The pulvilli are not minute, and although small (almost as long as the empodia and about one third the length of claws), are distinct.

Redescription:
Male (based on holotype in excellent condition). Head: Dark red-brown to black, with mainly white setose except for a few pale yellowish postocular setae. Antennae: Dark brown except for yellowish tip of style. Scape and pedicel white setose. Major ventral setae of pedicel project beyond level achieved by postpedicel. Basal element of style short (shorter than broad). Eye to face width ratio 1.8:1. Mystax longish, white. Frons and vertex white setose. Laterally situated frontal setae extending below antennal sockets, mingling with mystax. Occipital setae white. Some postoculars yellowish. Palps and proboscis white setose. Thorax: Dark red-brown to black. Pronotum white and pale yellowish setose. Mesonotum extensively setose except for narrow paramedial strips and large sutural and postsutural areas. Lateral macrosetae white (npl) and yellowish (spal & pal), other setae white anteriorly, pale yellowish posteriorly. Scutellum apruinose with poorly defined transverse groove (has somewhat crinkled appearance); disc asetose, 20 pale yellowish apical setae (in single row). Pleural setae mostly white except for some yellowish setae dorsally on anepisternum and on katepimeron. Katatergals white, long, shafts more or less smooth. Legs: Dark red-brown, mainly white and pale yellow setose, but some black setae at apex of tibiae and ventrally on tarsi. Claws longish, dark red-brown; empodia moderately long, yellowish; pulvilli minute to absent. Wings 3.7×1.5 mm, C white setose basally, membrane transparent. Haltere with orange-brown knob, dark brown stalk. Abdomen: Dark red-brown to black, white setose. Tergal setae mostly long, reclinate laterally, short, rather transparent medially (giving the impression of asetose areas medially).
Genitalia: Not dissected, but visible structures appear to conform to dissected and illustrated topotypic _ paratype (Figs 19, 20). Epandrium moderately developed and simple in structure, proctiger not extending greatly beyond it. External lobe of gonocoxite in lateral view broadly rounded proximally, fairly acutely pointed distally. Internal lobe fairly robust. Gonostylus somewhat shorter than internal lobe of gonocoxite and simple in structure. Hypandrium flattish, sub-triangular in ventral view, with long gradually tapering medial lobe extending well beyond external lobe of gonocoxite. Aedeagus fairly slender with fairly blunt tip. Female: Similar to male but have more yellowish setae which may even be described as orange in colour and in a few instances these outnumber white setae. A few specimens may even have some orange abdominal setae. Variation: Wing length _ 2.9-4.7 mm, ^3.2-5.4 mm. Distribution, phenology and biology: A fairly widely distributed species found in the Succulent Karoo and Nama-Karoo biomes of southern Africa (Fig. 43). Adults have been collected during spring and summer (October-December) ( Table 1). Experience tells me that the species is found in fairly arid, sandy places and that population densities may be low. Similar species: This species is similar to nilicola and xeromyia.

Redescription:
Male (based on holotype in good condition; the first three abdominal segments are glued to a card and pinned below the specimen along with a micro-vial containing the macerated genitalia). Head: Dark red-brown, blackish setose. Antennae: Dark red-brown except for tip of style which is yellowish. Scape and pedicel blackish setose. Major ventral setae of pedicel shortish, projecting to about halfway along postpedicels. Basal element of style short (only slightly longer than broad). Eye to face width ratio 1.8:1. Mystax of moderate length, blackish. Frons and vertex blackish setose. Laterally situated frontal setae not extending below antennal sockets. Occipital and postocular setae blackish. Palps and proboscis blackish setose.
Thorax: Dark red-brown, blackish setose. Pronotum dark red-brown setose. Mesonotum entirely setose except for narrow paramedial strips and sutural and postsutural spots. Scutellum apruinose with poorly defined transverse groove (has crinkled appearance); disc asetose, 12 dark red-brown apical setae. Pleural setae dark red-brown. Katepimeron asetose, katatergals long, shafts more or less smooth. Legs: Dark red-brown, mainly blackish setose (there are some small yellowish setae ventrally on tibiae and tarsi). Claws longish, dark red-brown; empodia longish yellowish, pulvilli small but clearly evident. Wings 3.5×1.5 mm. C black setose basally; membrane pale brownish stained except for distal third of wing. Haltere with orange-brown stalk and yellow knob. Abdomen: Dark red-brown; short blackish setose (slightly longer laterally). Genitalia (Figs 21, 22): Epandrium greatly reduced and simple in structure, proctiger extending well beyond it. Gonocoxite with fairly long external lobe tapering to broadly rounded tip, internal lobe long and fairly slender. Gonostylus long and slender. Hypandrium much flattened dorsoventrally, triangular in ventral view, with medial lobe extending almost as far as internal lobe of gonocoxite. Aedeagus robust with blunt tip. Female: Similar to male but displaying some sexual dimorphism. Females (previously unrecorded) are never entirely dark red-brown setose, but always have some pale yellow and a few orange setae (not commonly). Variation: Wing length _ 3.1-4.4 mm, ^3.1-4.6 mm. A fairly uniform species displaying some geographical variation in setal coloration. Males may be entirely dark red-brown setose like the holotype (i.e. those in the southern parts of the distribution) or possess some white or yellow setae (i.e. those in the northern parts of the distribution) on head and thorax (i.e. dorsal part of mystax, frontals, some postoculars, some pronotals, all mesonotals, all apical scutellars, anepisternals, proepimerals). While the mystax may be entirely red-brown it is usually pale yellow, but may have a few dark red-brown and white setae as well. The pronotum, mesonotum, scutellum and all pleura, including katatergite, are yellow setose. A few females may have some yellow leg setae and even a few yellow abdominal setae laterally. The extent and intensity of wing staining are variable. Those with darker staining frequently have small areas involved. Distribution, phenology and biology: Found fairly widely distributed within the succulent Karoo and Nama-Karoo biomes of southern Africa (Fig. 44), the species appears to favour arid places with sandy ground, succulents and scrub vegetation. It is active in the adult phase during spring and early summer (September-November) ( Table 1). Data suggest that population levels may be locally low. Similar species: This species is fairly distinctive and should not be confused with others. It is small, has a predominantly blackish mystax and small but visible pulvilli. Adams, 1905 Figs 3, 4, 23-26, 40 As this species displays some geographical variation as well as sexual dimorphism I provide redescriptions of the types of both major (^) and erebus (_) as they adequately represent much of the observed diversity.

Redescriptions:
Male (based on holotype of erebus in fair condition; both antennae broken off beyond pedicel, right pro-and mesothoracic legs broken off beyond trochanters and missing, left metathoracic leg lacking terminal four tarsomeres; the specimen is double mounted on a cellulose strip). Head: Dark red-brown to black with black, white and yellowish setae. Antennae: Dark red-brown (terminal parts missing). Scape and pedicel black setose ventrally, yellowish setose dorsally. Major ventral setae of pedicel missing. Eye to face width ratio 1.9:1. Mystax short, mixed black and yellowish ventrally, white dorsally. Frons and vertex pale yellow setose. Laterally situated frontal setae not extending below antennal sockets. Occipital setae black, postoculars pale yellow except for group of c. 5 black setae behind ocellar tubercle. Palps and proboscis black setose. Thorax: Dark red-brown to black. Mesonotum entirely pale yellow and orange setose except for narrow paramedial strips, sutural and postsutural spots. Lateral macrosetae pale yellow, other setae mixed white and pale yellowish. Scutellum apruinose with moderately defined transverse groove; disc asetose, apical setae numerous pale yellowish, arranged in about three rows. Pleural setae dark red-brown to black and pale yellowish. Anepisternum with dark red-brown setae anterodorsally and pale yellowish setae posterodorsally. Katepimeron weakly dark red-brown to black setose, katatergals long, shafts more or less smooth, mainly black setose except for some yellowish setae dorsally. Legs: Dark red-brown, mainly black setose (there are some small white and yellowish setae on pro-and mesothoracic legs). Claws longish, dark red-brown; empodia short yellowish (most broken), pulvilli minute to absent. Wings 5.3×2.6 mm. C white setose basally; membrane pale brownish stained except for narrow hind margin beyond fusion of CuA 2 and A 1 . Haltere red-brown. Abdomen: Dark red-brown; black setose except for posterolateral parts of T1-6 which are mostly white setose. Genitalia: Not dissected, but visible structures appear to conform to dissected genitalia of males from Nguruma (Kenya) (Figs 23, 24) and Zuarungu (Ghana) (Figs 25, 26). Epandrium greatly reduced, simple in structure, proctiger extending well beyond it. Gonocoxite with external lobe tapering to narrowly-rounded tip, internal lobe with deeply forked tip. Gonostylus shorter than internal lobe of gonocoxite, fairly robust with hooked tip. Hypandrium large, flattish, triangular in ventral view, with broad medial lobe extending almost as far as tip of internal lobe of gonocoxite and obscuring a view of other organs in ventral view. Aedeagus fairly robust, slightly curved in lateral view, with blunt tip. Female (based on lectolotype of major in good condition, slightly dusty). Head: Dark red-brown, white, pale yellow and dark red-brown setose. Antennae: Redbrown except for tip of style which is pale yellowish. Scape and pedicel mostly pale yellowish setose (a few small white setae present). Major ventral setae of pedicel project beyond level achieved by postpedicel. Basal element of style short (slightly longer than broad). Eye to face width ratio 2.3:1. Mystax mainly pale yellowish with group of white setae dorsally. Frons and vertex white, pale yellow setose. Laterally situated frontal setae not extending below antennal sockets. Occipital setae white, postoculars mixed white and pale yellow. Palps dark red-brown setose, proboscis white setose. Thorax: Dark red-brown. Mesonotum entirely setose except for narrow paramedial strips, sutural and postsutural spots. Lateral macrosetae light brown; other setae mostly mixed white, pale yellowish and dark red-brown. Scutellum apruinose with poorly defined transverse groove; disc asetose, apical setae numerous, difficult to count (c. 40), redbrown, yellowish and white. Pleural setae mostly white except for some pale yellowish setae dorsally on anepisternum and katatergite. Katepimeron white setose, katatergals white, pale yellowish, long, shafts more or less smooth. Legs: Orange-brown, pro-and mesothoracic femora dark red-brown, mainly white and pale yellow setose, but there are black setae terminally on tibiae and ventrally on tarsi. Claws longish, dark redbrown; empodia short yellowish; pulvilli minute to absent. Wings 6.2×2.7 mm; C white setose basally; R 4 with obvious remains of supernumerary crossvein (spurvein) basally; membrane pale brownish stained except for distal third of wing. Haltere with dark redbrown knob, orange-brown stalk. Abdomen: Dark red-brown, blackish and white setose; blackish setae small, confined to central parts of T1-4, white setae longish, erect laterally and on sterna, recumbent along posterior margins of T1-5 (some missing). Variation and sexual dimorphism: Size -wing length _ 4.6-7.5 mm (x -=5.8 mm, n=44), 4.1-7.9 mm (x -=6.0 mm, n=48). While on average females are slightly bigger than males the range in size is fairly significant in both sexes. This is also true for a local population (measurable erebus type specimens from Azare) where wing lengths are as follows -_ 5.8-6.7 mm (x -=6.1 mm, n=7), ^5.3-7.3 mm (x -=6.2 mm, n=14), although ranges were smaller. A fairly uniform species at any one locality, but displays sexual dimorphism in setal coloration (i.e. mystax -_ black and white (proportions vary), pale yellow; pleura -_ black and white, ^pale yellow; legs -_ mostly black setose, mostly pale yellow setose; and the degree of wing staining, _ darker stained, ^lighter stained (staining mostly confined to vein margins). Although there is variation within any given population, geographical variation is evidenced in the degree of wing staining, especially in _ (i.e. West Africa: The Gambia, Ghana -extensively strongly stained except for tip and hind margin (Fig. 4); Benin -basal half of wing strongly stained including entire costal cell. East Africa: Eritrea -basal half of wing strongly stained including entire costal cell; Kenya, Tanzania -strongly stained basally (Fig. 3) including half of costal cell (or c. 2/3 of wing weakly stained). Southern Africa: Mozambiquestrongly stained basally up to humeral crossvein (entire costal cell unstained)). Male terminalia show remarkably little variation over this extensive species range. Lectotype designation: Adams (1905) states that he saw three specimens and mentions both the male and female sex. However, all three specimens are female. He did not designate a holotype, and as the designation of a lectotype would provide taxonomic stability for this variable species, I hereby designate the only 'cotype' that shows no obvious damage as the lectotype. The other two females, both with visible damage (missing leg or detached wing) I consider to be paralectotypes. The lectotype is the smallest of the three specimens having wing measurements of 6.2×2.7 mm; the paralectotypes measure 7.1×3.0 and 8.0×3.6 mm respectively. Notes on synonymised species: Sisyrnodytes niger Bezzi, 1906: I have not seen the type material.  provides the following information for his Eritrean type specimen(s) 'Anseba, Halibaret, Tellini.' Although  lists niger as a synonym of major, and states that the holotype is 'in Udine, Italy' he may not have studied the material personally as he does not list Bezzi's locality for major. Although I have not verified the whereabouts of Bezzi's material, I have seen 3_ from Eritrea that carry old identification labels giving the name niger. These conform to my concept of major and so I accept this fairly longstanding synonymy. Sisyrnodytes disjunctus  The holotype is in excellent condition. Although labelled as a male it is a female as stated by . I can confirm that disjunctus is indeed a synonym of major. Sisyrnodytes erebus  The synonymy of erebus with major is supported by evidence gained during a study of the variation seen in all the material available to me. In addition male terminalia appear to be remarkably consistent over the extensive range of the species (as can be seen when comparing illustrations of males from Kenya (Figs 23,24) and Ghana (Figs 25, 26)). The fact that there is no male in the major type series does create some doubt concerning this synonymy, but that can only be dispelled when male specimens are available from the type locality.  With the synonymy of erebus the distribution of major is greatly extended into West Africa (Fig. 40). According to  major is active in the adult phase during 'December-February in north; July in south.' Specimens listed in this paper were collected in every month of the year except April ( Table 1). The species appears to be mainly winter-active, bearing in mind that it is found both north and south of the equator (Table 1). Although there is very little label data that provides information about habitat preferences,  reports that 'Dr. Burtt took it on burnt ground, where its charred, black-and-white appearance would give good concealment'. This association with burnt vegetation is supported by label data on some Gambian specimens (see above). Similar species: This species is similar to apicalis, aterrimus and vestitus.

Redescription:
Male (based on _ floccus syntype in excellent condition, some anterior mesonotal setae rubbed off). Head: Dark red-brown, white setose. Antennae: Red-brown except for tip of style which is yellowish. Scape and pedicel white setose. Major ventral setae of pedicel project beyond level achieved by postpedicel. Basal element of style short (as long as broad). Eye to face width ratio 1.3:1. Mystax longish, white. Frons and vertex white setose. Laterally situated frontal setae extend below antennal sockets, mingling with mystax. Occipital and postocular setae white. Palps and proboscis white setose. Thorax: Dark red-brown, white setose. Pronotum white setose. Mesonotum entirely setose except for paramedial strips, sutural and postsutural areas. Lateral macrosetae white. Scutellum apruinose with poorly defined transverse groove; disc asetose, c. 26 white apical setae. Pleural setae entirely white. Katepimeron setose, katatergals long, shafts more or less smooth. Legs: Red-brown, entirely white setose. Claws longish, dark red-brown; empodia short pale yellowish, pulvilli minute to absent. Wings 3.7×1.6 mm. C white setose basally; membrane transparent. Haltere brown-yellow. Abdomen: Dark red-brown; white setose, setae mostly reclinate, but some erect laterally. Genitalia: Not dissected, but visible structures conform to dissected and illustrated genitalia of a male from Tel Aviv (Israel) (Figs 27, 28). Epandrium greatly reduced and simple in structure, proctiger extending well beyond it. External lobe of gonocoxite somewhat triangular in shape with acutely pointed distal end. Internal lobe small with slightly inflated tip. Gonostylus short, fairly robust, slightly curved. Hypandrium fairly small, triangular in ventral view, medial lobe tapering fairly suddenly to rounded tip. Aedeagus fairly robust, tapering gradually to small, blunt tip. Female: Similar to male, although invariably with head and thorax somewhat yellow, golden or orange setose (i.e. ventral part of mystax, postoculars, pronotum, mesonotals (often mixed with white setae)). Abdomen may also have some yellowish setae. Variation: Wing length _ 3.2-4.4 mm, ^2.9-5.1 mm. Both sexes may have wing base yellowish or orange stained and legs red-brown (tarsi may be orange). Notes on synonymised species: Sisyrnodytes floccus Loew, 1856: I accept this long-standing synonym pending a modern revision of Palaearctic species. As this is the type species of the genus and stability is desirable through the designation of a lectotype, I designate the ZMHB male as lectotype and the female as paralectotype.
Dasypogon contrarius Walker, 1871: I have not seen the type(s),  states that the material is not in the BMNH and this I can confirm. In the absence of the specimen(s), which are apparently lost, the synonymy must be accepted. Sisyrnodytes rufus : I have studied a female (but labelled a male) syntype in MNHN.  studied both male and female specimens (number not stated), but the whereabouts of the male(s) is not known. I accept the synonymy of this species, but believe that a review of the Palaearctic material is necessary before this synonymy can be accepted with confidence. Type locality: Rondani (1850) did not give a precise locality for his material, but merely stated 'AEgypti'. Subsequent workers have not designated a type locality, and I too refrain from doing so as this is best undertaken after a revision of the Palaearctic Sisyrnodytes fauna. Distribution, phenology and biology:  records the distribution as 'Morocco, Algeria, Egypt, Southern Arabia'. Some twenty years later he summarised the distribution as 'Egypt; widespread N. Afr. from Morocco to Egypt & South Yemen' (Oldroyd 1980). I have seen material I believe to be nilicola from Algeria, Egypt, Israel, Mauritania, Marocco and Saudi Arabia (Fig. 40). While I have not seen any Yemenese material I include the species in this review as Wulp (1899: 86) recorded a single female (under the name brevis) from Aden (12°50'N:45°00'E) and I have seen a specimen from Mauritania, also a country likely to have Palaearctic faunal elements.  records the species (as brevis) from Eritrea, but the identification is probably suspect. Efflatoun (1937: 255), writing about the Egyptian asilids states 'My records extend from the beginning of February (Gebel Elba) to the end of June (Sollum)', while  reports adult activity as 'December-June'. My limited data indicate activity in March, April, May and June (Table 1). While labels provide little biological information, Efflatoun (1937) goes on to say that this species 'is one of our commonest Asilids' and that it 'is found everywhere in dry sandy localities'. Comments: This species superficially resembles dasykylon from South Africa, especially with respect to mystacal development. As nilicola resembles Theodor's engeddensis from Palestine, and three unidentified species known to me from Morocco and Saudi Arabia, there is a definite need for a revision of the Palaearctic Sisyrnodytes fauna. Details of the unidentified Moroccan and Saudi Arabian specimens are as follows:  Sisyrnodytes niveipilosus Ricardo, 1925 Figs 29, 30, 41 Sisyrnodytes niveipilosus : Ricardo 1925: 247;Oldroyd 1957: 87;1974: 74;1980: 368 (catalogue);Hull 1962: 191  Thorax: Dark red-brown to black. Pronotum white and yellow setose. Mesonotum distinctly humped, entirely long setose except for narrow paramedial strips, sutural and postsutural spots. Lateral macrosetae yellow-orange, other setae of similar development, mostly mixed white and pale orange, but there are clusters of uniformly white, brown or orange setae situated mainly anteriorly. Scutellum apruinose with poorly defined transverse groove (has crinkled appearance); disc asetose, apical marginal setae numerous pale yellowish and white. Pleural setae slightly wavy, mostly orange except for some white setae dorsally on anepisternum. Katepimeron orange setose, katatergals orange, long, shafts slightly wavy. Legs: Orange, proximal two-thirds of femora dark red-brown, mainly orange setose, but there are some small white setae too. Claws longish, dark red-brown to black; empodia yellowish, pulvilli minute to absent. Wings 7.0×3.1 mm. C white setose basally; membrane transparent. Haltere yellow. Abdomen: Dark red-brown to black; mainly long white setose except for anterior parts of T2-5 which have shorter yellowish setae. Genitalia: Not dissected, but visible structures appear to conform to dissected and illustrated genitalia of a topotypic _ from Bulawayo (Figs 29,30). Epandrium reduced in size and simple in structure, slightly bulbous proctiger extending well beyond it. Gonocoxite fairly large, external lobe tapering to fairly acute tip in lateral view, internal lobe long with down turned tip. Gonostylus fairly long, simple in structure. Hypandrium reduced, short and broad (twice as broad as long), transversely oval with broadly-rounded apex. Aedeagus robust, slightly dorsoventrally compressed, with wing-like projections laterally and rounded tip. Female: Similar to male. Somewhat variable in setal coloration. Antennal setae white or yellow; mystax may be uniformly white, white dorsally and yellow to orange ventrally or white and yellow with some dark red-brown setae along epistomal margin (Namibian material); abdominal terga may be predominantly white setose or may have distinct bands of white and yellowish setae. Variation: Wing length _ 5.4-7.1 mm, ^5.1-7.8 mm. Males, known only from Zimbabwean type locality demonstrate little variation. Topotypic male antennae red-brown; major ventral setae of pedicel longer than postpedicel. Lectotype designation:  described the species on 'Paratypes (five females) from Bulawayo (Rhodesia Museum). , under the heading 'Holotype', wrote 'I do not think Miss Ricardo can seriously have meant to describe a species from paratypes only, without a holotype, and I imagine a line of text was omitted. There are specimens from Bulawayo in the British Museum, which are labelled "paratype ^" in Miss Ricardo's handwriting, but they are undoubtedly males. The best plan, no doubt, would be to consider them all as syntypes.', and did not designate a lectotype. My experience suggests that all Ricardo's newly described species, unless based on single specimens, are usually considered to be syntypes. I have studied only the single specimen listed above and here designate it as lectotype. The other four specimens mentioned by Ricardo I consider paralectotypes. Oldroyd (1974) stated 'Types in London and Bulawayo', and Dr Erica McAlister confirms that, apart from the lectotype, there are three other cotypes at the BMNH. This means that the National Museum of Zimbabwe, Bulawayo, probably has a single paralectotype. While I have not checked the gender of all these specimens,  was confident that they were all males and I accept his determinations. It is odd that Oldroyd failed to mention another two specimens, both females, in the BMNH (listed below) as these must surely have been available to him, when he reviewed the genus in 1957. He may not have been sure of their identification however, as the specimens do not carry his identification labels. The evident sexual dimorphism may have caused him some uncertainty.
Namibia, Botswana and South Africa (Fig. 41). Adult activity was recorded as 'April-May'  but my data show that specimens have been collected in April, May, June, July and August (i.e. autumn and winter) ( Table 1). Labels provide no biological data. Similar species: This species is distinctive and should not be confused with any other. sp. n. Figs 31,32,43 Etymology: From Greek oligos (few) and thrix (hair). Refers to the small number of apical scutellar setae.

Redescription:
Male (based on holotype in excellent condition; slightly greasy). Head: Dark red-brown to black with mainly white setae, but some pale yellow and dark red-brown setae present. Antennae: Dark red-brown except for tip of style which is pale yellowish. Scape and pedicel mostly white setose, major setae pale yellowish. Major ventral setae of pedicel project beyond level achieved by postpedicel. Basal element of style short (shorter than broad). Eye to face width ratio 1.7:1. Mystax shortish, mostly white (dorsally) and yellowish (ventrally), but a few dark red-brown setae laterally on epistomal margin. Frons and vertex mainly white setose except for some yellowish setae on either side of ocellar tubercle. Laterally situated frontal setae not extending below antennal sockets. Occipital setae white, more robust postoculars yellowish. Palps dark red-brown and yellowish setose, proboscis white setose. Thorax: Dark red-brown to black. Prothorax yellow and white setose. Mesonotum entirely setose except for paramedial strips, sutural and postsutural spots. Lateral macrosetae yellowish; other setae mixed white and yellowish. Scutellum apruinose with poorly defined transverse groove; disc asetose, 6 yellowish and white apical setae. Pleural setae mostly yellowish except for white setae dorsally on anepisternum. Katepimeron yellowish setose, katatergals yellowish, long, shafts more or less smooth. Legs: Dark red-brown, mainly white setose, major setae yellowish, blackish setae distally on tibiae and ventrally on tarsi. Claws longish, dark red-brown; empodia short yellowish; pulvilli minute to absent. Wings 4.6×1.9 mm; C white setose basally; membrane transparent except for small pale yellow-brown basal area. Haltere with pale yellow knob, light brown stalk. Abdomen: Dark red-brown, white setose. Tergal setae well developed laterally and along posterior margins, other setae tiny, transparent (giving anteromedial parts of terga an asetose appearance). Genitalia (Figs 31,32): Epandrium reduced and simple in structure, proctiger extending beyond it. Gonocoxite with shortish external lobe tapering to acute tip, internal lobe fairly robust, with somewhat bilobed distal end. Gonostylus fairly well developed, simple in structure. Hypandrium somewhat flattish with rounded proximal part and long, laterally compressed medial lobe projecting beyond levels reached by gonocoxite and gonostylus. Aedeagus fairly slender with small, tapering, blunt tip.
Female: Similar to male. Distribution, phenology and biology: Known only from the type locality (Fig. 43) and collected only during April (Table 1). Similar species: This species is similar to ausensis and brevis.

Redescription:
Male (based on holotype in good condition; right metathoracic leg broken off beyond trochanter).
Head: Dark red-brown to black, white and pale yellow setose. Antennae: Light brown except for tip of style which is yellowish. Scape and pedicel white setose. Major ventral setae of pedicel project beyond level achieved by postpedicel. Basal element of style short (only slightly longer than broad). Eye to face width ratio 1.7:1. Mystax moderately well developed, white. Frons and vertex white setose. Laterally situated frontal setae extend below antennal sockets, merging with dorsal mystical setae. Occipital setae white, postoculars white except for a few (c. 10) yellowish macrosetae behind ocellar tubercle. Palps and proboscis white setose. Thorax: Dark red-brown to black. Pronotum white and yellow setose. Mesonotum extensively setose except for narrow paramedial strips, sutural and large postsutural spots. Lateral macrosetae pale yellowish, other setae fine white (anteriorly) and yellow (posteriorly). Scutellum apruinose with moderately well-defined transverse groove; disc asetose, 12 shortish yellow-brown apical setae arranged in two groups separated by a small medial gap. Pleural setae mostly white except for orange katepimerals. Anepisternum with white setae; katatergals long, shafts more or less smooth, white. Legs: Femora dark red-brown except for orange distal tip, tibiae and tarsi orange. Claws longish, black, empodia moderately long, yellowish, pulvilli minute to absent. Wings 4.5×1.8 mm. C orange setose basally; membrane pale brownish stained basally (including following cells-basal costal, intervenal, basal parts of costal, basal radial, basal medial and posterior cubital). Haltere yellow. Abdomen: Dark red-brown to black; white setose. T1-3 with minute setae, except laterally, appearing asetose; T4-6 extensively covered with long reflective, reclinate and erect setae. Genitalia: Not dissected, but visible structures conform to dissected and illustrated genitalia of a male from Serowe (Botswana) (Figs 33, 34). Epandrium greatly reduced, simple in structure, proctiger extending well beyond it. Gonocoxite with fairly long and somewhat narrow (in lateral view) external lobe tapering to broadly-rounded tip, internal lobe longish with slightly bilobed distal end. Gonostylus short, simple in struc-ture. Hypandrium with broad, transversely oval proximal region and moderately long medial lobe distally. Medial lobe with narrow stalk-like base and bulbous apex. Aedeagus fairly slender, bent downward at about midlength, and with small, blunt tip. Female: Similar to male but fairly variable, especially with respect to setal colour. Females possess numerous orange setae i.e. antennal setae may be orange, mystax may be largely orange, ocellars and postoculars may be mostly orange, almost entire mesonotum covered with orange setae except along posterior parts where they are yellow. Variation: Wing length _ 3.4-7.5 mm, ^3.5-6.5 mm. Males generally smaller than females (measurements are skewed by a single large male). The intensity and extent of basal wing staining is variable in both sexes.  (BMNH). Note: The Zimbabwean female, found with niveipilosus material in the BMNH, has label data identical to the holotype. Oldroyd probably failed to recognise this and to use the specimen as a paratype as both species are known from Bulawayo. Sexual dimorphism and the fact that this female is the largest I have seen (wing 6.5 mm long) may also have caused some confusion.
Distribution, phenology and biology: A fairly widely distributed species (Fig. 42) found in southern Zimbabwe, eastern Botswana and the central parts of South Africa. Adults, collected from August through to December (Table 1), fly during spring and summer in areas receiving rain at that time of the year. I have collected the species in hot, dry, rocky bushveld and dry, rocky savannah biomes. Similar species: This species is reasonably distinctive, but has some similarity to ausensis, brevis and oligotrichus.

Redescription:
Male (based on holotype in excellent condition). Head: Dark red-brown with dark red-brown, white and pale orange setae. Antennae: Dark red-brown except for tip of style which is yellowish. Scape and pedicel dark redbrown setose. Major ventral setae of pedicel project beyond level achieved by postpedicel. Basal element of style short (only slightly longer than broad). Eye to face width ratio 2.0:1. Mystax shortish, dark red-brown except for a few small white setae dorsally. Frons and vertex white and pale orange setose. Laterally situated frontal setae not extending below antennal sockets. Occipital setae dark red-brown, postoculars mixed white and pale orange. Palps and proboscis black setose. Thorax: Dark red-brown. Mesonotum entirely setose except for narrow paramedial strips, sutural and postsutural spots. Lateral macrosetae dark red-brown (npl) and pale orange (spal & pal), other setae mostly mixed dark red-brown, white and pale orange, but there are small clusters of uniformly white setae situated anteriorly and at level of transverse suture. Scutellum apruinose with poorly defined transverse groove (has crinkled appearance); disc asetose, c. 12 dark red-brown major apical setae accompanied by weaker yellowish setae. Pleural setae dark red-brown and orange. Anepisternum orange setose anterodorsally, dark red-brown posterodorsally, katepimeron orange setose, katatergals dark red-brown, long, shafts more or less smooth. Legs: Dark red-brown, mainly dark red-brown setose (there are some small white and orange setae dorsally on pro-and mesothoracic legs). Claws longish, dark red-brown; empodia yellowish, pulvilli minute to absent. Wings 5.3×2.5 mm. C white setose basally; membrane pale brownish stained basally. Haltere dark red-brown. Abdomen: Dark red-brown; dark red-brown setose except for posterior parts of T1-2 which are white setose (a few white setae also on T3). Genitalia: Not dissected, but visible structures conform to dissected and illustrated genitalia of a male from Gemsbok Pan (Figs 35, 36). Epandrium greatly reduced and simple, proctiger extending well beyond it. Gonocoxite with external lobe tapering to fairly acute tip, internal lobe slender, fairly long. Gonostylus fairly long, slender. Hypandrium flattish, sub-triangular in ventral view, with fairly broad (in ventral view) medial lobe projecting beyond all other structures. Aedeagus fairly robust, tapering to broadly-rounded apex. Female: Similar to male, but possess far more white and yellowish setae (e.g. mystax is yellow and white setose-one has a few dark red-brown setae along epistomal margin; antennae yellow setose; thorax, including legs, predominantly yellowish setose; abdomen with all visible terga equipped with white setae posteriorly); wing membranes are weakly orange stained adjacent to veins. Variation: Wing length _ 5.2-6.4 mm (x -=5.7 mm, n=4), ^6.4-7.1 mm (x -=6.8 mm, n=2); males generally smaller than females. The South African male is somewhat red-   Acnephalum Macquart, 1838 Acnephalum sericeus , comb. n.
Sisyrnodytes sericeus : 72. Oldroyd (1974 described this species on a single male holotype from South Africa labelled 'Gamtoos Valley bush / Hankey area / 5. 12. 67 3324DA / B&P Stuckenberg'. I have studied this specimen, housed in NMSA, and can report that it was misplaced in Sisyrnodytes and should be referred to Acnephalum. While a revision of Acnephalum is being undertaken, I use this opportunity to propose this new combination.

Taxonomy
Of particular interest is the fact that Dikow (2009) placed Sisyrnodytes in the subfamily Willistonininae separated from the Stenopogininae along with two other Afrotropical genera Acnephalum Macquart, 1838 andTrichoura Londt, 1994, as well as two Nearctic genera (Willistonina Back, 1908 andAblautus Loew, 1866). While I acknowledge that the Afrotropical genera listed are distinctive, I have decided to refrain from adopting Dikow's arrangement until I have had an opportunity to evaluate its stability for myself. I have reason to exercise caution as the following facts are emerging from my current study of Acnephalum: (1) Dikow used A. cylindricum Oldroyd, 1974 to represent the genus. My study suggests that this is not only a synonym of A. gracilis (Hermann, 1907), but that the species should be reassigned to Sporadothrix Hermann, 1907, because it differs in significant ways from other species currently assigned to Acnephalum.
(2) Some of the characters used to justify the Willistonininae may not be found in all representatives of the included genera. For example, some species of Acnephalum have discal scutellar setae. It is hoped that Dikow will soon be in a position to publish a key to the subfamilies of Asilidae that would allow other taxonomists to better evaluate the taxa he has proposed.

Distribution
Although sampling has generally not been adequate, Fig. 39 shows the genus to be widely distributed. The majority of species are recorded from southern Africa, reflecting the collecting activities of South African institutions. While most of the southern African species are to be found in Fynbos, Nama-Karoo and Succulent Karoo biomes, and have fairly restricted ranges, there are a few species adapted for life in Savannah and are far more widely distributed. There are very few records from open Grassland and none from Forest biomes.

Biology
Very little is known about the biology of Sisyrnodytes species. All species appear to rest on the ground, either on open sand or on small stones and rocks. Some specimens have been collected in areas where grassland had been recently burnt and there may be some as yet unexplained association with burning as the species involved are dark with ashy coloration that tends to give them a high degree of camouflage. While some species may be found in the winter rainfall region of southern Africa, most occupy summer rainfall regions. Some adults of some species are active during the cooler winter months, but most are summer active. I know of only a few prey records (for brevis)-Hymenoptera (Cynipidae), Hemiptera (Lygaeidae) and Coleoptera (probably Chrysomelidae). These records do not provide any insights into any dietary preferences that may exist. Months start with July so as to centre the data for summer active species.