Microphontes megoura Londt, 1994

Markee, Amanda & Dikow, Torsten, 2018, Taxonomic revision of the assassin-fly genus Microphontes Londt, 1994 (Insecta, Diptera, Asilidae), African Invertebrates 59 (2), pp. 195-237 : 195

Microphontes megoura Londt, 1994 Figs 38-43, 60-61, 71

Microphontes megoura Londt, 1994: 87.

Diagnosis.

The species is distinguished from congeners by the small size with a wing length of 3.2-4.1 mm, distinctly wider than long and transversely rectangular abdominal tergites, partly macrosetose postpronotal lobes, macrosetose posterior anepisternum and distribution in Namaqualand in western-most South Africa.

Redescription.

Head: wider than high, brown; vertex and compound eyes at same level; facial swelling indistinct, only lower facial margin slightly developed, greyish-silver pubescent; mystax white macrosetose, restricted to lower facial margin, short, reaching tip of proboscis; ommatidia of same size; postgena posterior margin simple, smooth; frons (at level of antennal insertion) slightly diverging laterally, grey pubescent, yellowish setose; ocellar tubercle light brown pubescent, light brown setose; vertex greyish-light brown pubescent, yellowish to light brown macrosetose; median occipital sclerite (m ocp scl) with several yellowish setae, rarely with several yellowish macrosetose; postocular (pocl) setae slightly angled anteriorly distally, yellowish macrosetae; occiput predominantly grey pubescent, yellowish setose; compound eye posterior margin (in lateral view) straight or slightly curved throughout.

Proboscis and maxillary palpus: proboscis straight, brown; postmentum plate-like, straight, ventral margin entirely smooth, white setose ventrally; prementum circular, with dorso-median flange, asetose; labella reduced, fused to prementum only ventrally, only forming distal tip of proboscis, rounded; maxillary palpus light brown, two-segmented, long yellowish setose, cylindrical; stipites fused medially, but with V-shaped indentation, apubescent, long white setose.

Antenna: orange, lightly grey pubescent; scape approximately as long as pedicel, short and long yellowish setose and macrosetose ventrally; pedicel short yellowish setose dorsally and long yellowish macrosetose ventrally; postpedicel cylindrical (same diameter throughout), approximately 2 × as long as scape and pedicel combined, asetose; stylus comprised of 1 element, 0.15 × as long as postpedicel, asetose; apical seta-like sensory element situated apically in cavity on stylus.

Thorax: orange to light brown, scutum with median longitudinal stripe and shorter sublateral longitudinal stripes brown; prosternum white pubescent, separated from proepisternum, square to rectangular in shape (straight dorsally); proepisternum white pubescent, long yellowish macrosetose; cervical sclerite long yellowish setose; antepronotum white pubescent, short yellowish setose medially, long and weakly yellowish macrosetose laterally; postpronotum white pubescent, long yellowish setose medially and sub-laterally, long and weakly yellowish macrosetose laterally; postpronotal lope long yellowish setose and longer yellowish macrosetose anteriorly; pleuron white pubescent; proepimeron long white setose anteriorly; anepisternum long yellowish setose dorsally (setae directed dorsally), long yellowish macrosetose postero-medially (macrosetae directed posteriorly), supero-posteriorly long yellowish setose (indistinguishable from other dorsal anepisternal setation); anterior basalare long yellowish setose medially, posterior basalare asetose; anepimeron asetose, katepisternum asetose, katepimeron asetose, katatergite long yellowish macrosetose, meron + metanepisternum asetose, metakatepisternum asetose, metepimeron asetose, anatergite asetose; scutum white to greyish pubescent, scutum setation: long yellowish setose, setae with small sockets, 1 npl setae, 1 spa setae, 1-2 pal setae, 2-3 long yellowish postsutural dc macrosetae, acr setae long yellowish presuturally and postsuturally, median posterior scutum (between dc setae) long yellowish setose, setae directed anteriorly; scutellum grey pubescent, ds sctl setae present, long yellowish setae, ap sctl setae present, 6-8 long yellowish macrosetose; postmetacoxal area entirely membranous.

Leg: orange to light brown, apubescent, all setae circular in cross section; pro coxa orange to light brown, white pubescent, white setose and macrosetose; pro femur orange to light brown, short white setose, 5-6 long white setae in antero-ventral and postero-ventral rows, yellowish macrosetose: 3-4 posterior to dorso-posterior distally; pro tibia orange to light brown, short white setose, yellowish macrosetose: 4 in 1 antero-dorsal row, 5-6 in 1 postero-ventral row, distal tip with 3-4 long yellowish macrosetae; mes coxa orange to light brown, white pubescent, yellowish macrosetose; mes femur orange to light brown, short white setose, 4-5 long white setae in antero-ventral and postero-ventral rows, yellowish macrosetose: 1 anterior proximally, 2-3 antero-dorsal distally, 2-3 posterior distally; mes tibia orange to light brown, short white setose, yellowish macrosetose: 4 in 2 dorsal rows, 3 in 1 antero-ventral row, 3 in 1 postero-ventral row, distal tip with 5 long yellowish macrosetae; met coxa orange to light brown, white pubescent, white setose and yellowish macrosetose, anteriorly without any protuberance; met trochanter yellowish macrosetose, cylindrical, medially without any protuberance; met femur orange to light brown, short white setose, yellowish macrosetose: 6 in 1 anterior row, 6 in 1 antero-ventral row, 3-4 long in 1 postero-ventral row, 1 distal dorsally; met tibia orange to light brown, straight, short white setose, yellowish macrosetose: 5 in 1 anterior row, 4 in 1 antero-ventral row, 5 in 1 dorsal row, distal tip with 5 short yellowish macrosetae; proximal pro and mes tarsomere as long as following 2 tarsomeres combined, proximal met tarsomere longer than 2 following tarsomeres combined, proximal met tarsomere as wide as following tarsomeres; pro tarsomeres 1-5 white setose dorsally, tarsomeres 1-4 short yellowish macrosetose disto-laterally and disto-dorsally, tarsomere 5 weakly yellowish macrosetose distally; mes tarsomeres 1-5 white setose dorsally, tarsomeres 1-4 short yellowish macrosetose disto-laterally and disto-dorsally, tarsomere 5 weakly yellowish macrosetose distally; met tarsomeres 1-5 white setose dorsally, tarsomeres 1-4 short yellowish macrosetose disto-laterally and disto-dorsally, tarsomere 5 weakly yellowish macrosetose distally; pulvilli well-developed (as long as claw); claw abruptly angled distally, pointed; empodium setiform, approximately ½ length of claw.

Wing: 3.2-4.1 mm.

Abdomen: shape compressed, T2-3 distinctly transversely rectangular (length to width ratio> 1:3), orange to light brown, tergites smooth, setae with small sockets only; T1 white setose, postero-laterally long white macrosetose, white pubescent, anterior ½, except laterally, membranous, dorsal surface smooth, without protuberances; T2-8 entirely sclerotised, orange to light brown, white pubescent: in dorsal view T2-7 appearing predominantly apubescent except laterally, in lateral view T2-7 appearing apubescent in posterior ½ except lateral margin, short white setose, long white setose antero-laterally on T2, marginal macrosetae absent from T2-8, medial macrosetae absent from T2-8; S1-8 orange to light brown, lightly grey pubescent, short white setose.

Female: T6-7 predominantly grey pubescent, T8 apubescent medially and posteriorly, setation directed dorsally; postero-paramedian T8 pores present, indistinct, opening not elevated above tergite surface; T8 without any internal apodeme anteriorly; T10 divided into 2 heavily sclerotised acanthophorite plates, with 6-8, light brown acanthophorite spines per plate; 3 spermathecae, all equally large, reaching anterior end of segment 5; common spermathecal duct short, not extending beyond tip of genital fork ( S 9, furca), individual spermathecal ducts short or long; spermathecal reservoirs spherical, heavily sclerotised; genital fork ( S 9, furca) formed by single, inverted V-shaped sclerite, median sclerite (at posterior tip) absent, anterior apodeme absent.

Male (Figs 60-61): T1-T7 and S1-S7 entire, T8 + S8 reduced to ring of sclerites; hypopygium orange to light brown, rotated by 180°; hypandrium well-developed, triangular, posterior margin with long postero-median projection; gonocoxal apodeme present, short, entirely confined to hypopygium.

Type locality: SOUTH AFRICA: Northern Cape: Kamieskroon, 30°12'00"S, 017°56'00"E (-30.20, 17.93).

Material examined.

SOUTH AFRICA: Northern Cape: 5♀ 4♂ Kamieskroon , 30°12'00"S, 017°56'00"E, 1936-11-00, Museum Staff (1♂ Holotype SAM-DIP-A015480 , SAM, Paratypes 1♂ NMSA-DIP-4767 , NMSA, 5♀ SAM-DIP-A015481 - SAM-DIP-A015483 , SAM-DIP-A015486 - SAM-DIP-A015487 , SAM, 2♂ SAM-DIP-A015484 - SAM-DIP-A015485 , SAM) .

Distribution, biodiversity hotspots, phenology and biology.

Known only from the type locality in the Northern Cape of South Africa (Fig. 71). A rarely collected species known only from a single collecting event in 1936 (Table 1). The species is endemic to the Cape Floristic Region biodiversity hotspot. Adult flies are active in early summer in a winter rainfall region (Table 2). Nothing is known of the biology.