Laphyctis eremia, Londt & Dikow, 2018

Londt, Jason G. H. & Dikow, Torsten, 2018, A review of the assassin-fly genus Laphyctis Loew, 1858 with descriptions of two new species (Diptera, Asilidae, Laphriinae), African Invertebrates 59 (1), pp. 75-106 : 76-80

Laphyctis eremia sp. n. Figs 3-5, 18, 24, 28-33, 41, 56

Etymology.

Gr. eremia - desert, wilderness. Refers to the habitat occupied by the species.

Description.

Based on all available material. General appearance as in Figs 28-33.

Head: Dark red-brown to black, but colour masked by strong gold-silver pruinescence, shiny white and pale yellow setose. Antennae: mostly dark red-brown, fine silver pruinose, especially scape. Scape strongly pale yellow setose ventrally. Pedicel almost asetose, only a few tiny setae distally. Postpedicel with broad terminal cup-shaped style, opening oblique and enclosing a spine-like sensory element. Segmental length ratios = 1: 0.7: 2.2: 0.4. Face dark red-brown to black, but colour masked by strong gold-silver pruinescence (except for extreme lateral margins of epistomal margin). Width of one eye: face ratio = 1: 0.94 (face slightly narrower than width of 1 eye). Face projecting strongly ventrally, epistomal margin medially distinctly pointed, facial profile plane (Fig. 18). Mystacal macrosetae shiny pale yellow, confined to narrow band along lower facial margin, not extending beyond ventral quarter of face. Dorsal region of face fine white setose. Frons and vertex dark red-brown to black, colour masked by dull gold-silver pruinescence, fine white setose. Ocellar tubercle fine white setose (no macrosetae). Postocular (occipital) region dark red-brown to black, colour masked by strong gold-silver pruinescence. Occiput with rows of c. 7 short, pale yellow macrosetae dorsally and many fine, shiny white setae, mostly ventrally. Palpi dark red-brown, 2-segmented, fine white setose. Proboscis straight, shiny dark red-brown to black, fine white setose proximally and distally.

Thorax: Dark red-brown to black, uniformly strongly gold-silver and silver pruinose, pale yellow and fine white setose. Pronotum dark red-brown, silver pruinose, fine white setose. Mesonotum dark red-brown, entirely gold-silver pruinose, uniformly fine shiny yellow-white microsetose except for moderately developed, yellow lateral macrosetae (1 npl, 3 spal), pal setae absent. Scutellum dark red-brown to black, entirely fine gold-silver pruinose. Discal scutellar setae fine yellow, apical scutellar setae absent. Pleura dark red-brown to black, entirely silvery pruinose, fine white setose. Katatergal macrosetae moderately developed, fine white. Anatergites uniformly strongly silver pruinose, asetose. Postmetacoxal area membranous. Legs: Fairly uniform dark red-brown to black, proximal ends of femora and tibiae at least partly orange-brown, shiny white to pale yellow setose. Coxae fine silver pruinose. Claws well-developed, black with brown-orange basal parts. Empodium red-brown, straight, slightly longer than claws. Pulvilli pale yellow, well-developed. Wings (Fig. 24): ♂ (8) 9.0 × 3.4 mm, ♀ (15) 9.2 × 3.4 mm (females on average slightly larger than males). Venation: All marginal cells open except for m3 and cua, which are closed and stalked. Veins yellow-brown to brown, membrane unstained, transparent, microtrichose (except for small parts of some basal cells). Cell cup with weak bordering vein (C) and microsetae. Alula well-developed, lacking bordering vein and microsetae.

Abdomen: Dark red-brown to black, fine white and yellow microsetose, macrosetae yellow-white, gold-silver and silver pruinose. Tergites (T1-6 well-developed and clearly evident, others reduced and hidden from view below T6) dark red-brown to black, anteriorly yellow microsetose, gold-silver pruinose, posteriorly white microsetose, silver pruinose. T1-6 with pale yellow-white medial macrosetae (in ♂ T6 is usually without medial macrosetae). Sternites red-brown, fine white setose, silver pruinose.

Male terminalia (Figs 34-36): Genital bulb rotated clockwise through approximately 180°. T7-8 and S7-8 reduced and poorly defined. Epandrium large, almost twice as long as broad in dorsal view, bilobed in distal quarter, tips of lobes somewhat pointed (Fig. 34). Proctiger short, deep, projecting only slightly beyond distal epandrial lobes. Hypandrium poorly defined, margins difficult to appreciate, especially in lateral view, weakly sclerotized, subcircular in ventral view (Fig. 36), slightly longer than wide, terminating at a point where opposing gonocoxites almost meet midven trally. Gonocoxites well-developed, in lateral view approximately as broad and a little more than half as long as epandrium, broadly rounded distally, long, densely arranged macrosetae on distal margin of gonocoxite. Gonostyli subdivided at base into two lobes, a dorsal lobe, bent at almost 90° near its base which tapers gradually to a small down-curved distal tip, and a strong ventral lobe that has a straight basal region tipped by a down-curved terminal hook. Phallus with a slender basal region tipped with a relatively large, terminal, subtriangular bulbous head that is down-curved distally.

Female terminalia (Fig. 37): Relatively broad and dorsoventrally flattened. Segments 1-6 well-developed, segments 7-8 reduced. Subgenital plate moderately well-developed, almost twice as broad as long, with uniquely undulating, trifurcate distal margin.

Type material.

Holotype. Namibia: Erongo: 1♂ holotype 'Namibia: Erongo: Namib-Skeleton / Coast National Park, Gobabeb, / Kuiseb riverbed, dry, open, sandy / riverbed, perching on sand, 23°33'35"S, / 015°02'06"E, 389 m, 05.ii.2012, / T. Dikow’, ' Laphyctis / sp. / det. T. Dikow 2012', USNMENT00832227' (NMNW).

Paratypes. Angola: Namibe: 1♂ 'Angola (A11) / Bruco. [c. 15°07'00"S, 13°11'00"E 738m] 26.ii - / 2.iii.1972', 'Southern / African Exp. / B.M. 1972-1', ’NHMUK010624214’ (BMNH). Namibia: Kunene: 3♂1♀ 'Khowarib Schlucht / SE 1913Bd [Khowarib Lodge c. 19°15'35"S, 13°52'38"E 690m] / 15-i-1980 / Univ. v. Pretoria’ [NSMA-DIP-71759-61 (♂), NSMA-DIP-71758 (♀)] (NMSA); 2♂ 'Anabis Farm [c. 20°00'08"S, 14°38'33"E]/ 2114BA S.W.A. / 22.2.1969 / B. Lamoral’ [NSMA-DIP-07851, 71768]; 1♂ 5♀ 'South West Africa 2014Dd / Damaraland nr. Rooipoort / Farm at Ugab River [c. 20°51'31"S, 14°57'33"E], 600m / 6.ii.1974 ME & BJ Irwin / Sandy river bottom’ [ID Fisher] [NSMA-DIP-07844 (♀), NSMA-DIP-71762-5 (♀), 71766 (♂)]; 1♂ 'Ugab Riv. Bridge [c. 21°09'50"S, 13°39'54"E 20m] / 2213BA S.W.A. / 19.2.1969 / B. Lamoral’ [ID Oldroyd] [NSMA-DIP-71767]; Erongo: 1♂ 'S. W. Africa (29) / Kahn River, 5 mls. / N. Usakos [c. 21°56'10"S, 15°41'29"E 1043m] / 30 –31.i.1972’, 'Southern / African Exp. / B.M. 1972-1', ' Laphystia / gigantella Loew / det. H. Oldroyd 1973 ’,’NHMUK010624208’ (BMNH); 1♀ 'S. W. Africa (29) / Kahn River, 5 mls. / N. Usakos / 30 –31.i.1972’, 'Southern / African Exp. / B.M. 1972-1', ’NHMUK010624217’ (BMNH); 1♂ 'S. W. Africa (28) / Goanikontes [c. 22°40'06"S, 14°49'04"E 157m], 21 mls. / E. Swakopmund / 30.i.1972', 'Southern / African Exp. / B.M. 1972-1', ’NHMUK010624207’ (BMNH); 2♂ 1♀ 'S. W. Africa (22); / Kuiseb Canyon. / 23 18'S, 15 45'E [c. 23°17'59"S, 15°45'32"E 770m] / 22 –23.i.1972’, 'Southern / African Exp. / B.M. 1972-1', 'NHMUK010624206 & 13 [2♂] & 15 [1♀]' (BMNH); 5♂ 9♀ 'South West Africa 2315Ca / Namib Desert Park, Kuiseb / River at Gobabeb [c. 23°33'50"S, 15°02'24"E 395m], 400m / 12.ii.1974 ME & BJ Irwin / Riverine forest and sand’ [ID Fisher] [NSMA-DIP-07857 (♂), 71769-81]; 1♂ 2♀ 'Namibia: Erongo: Namib-Skeleton / Coast National Park, Gobabeb, / Kuiseb riverbed, dry, open, sandy / riverbed, perching on sand, 23°33'35"S, / 015°02'06"E, 389 m, 05.ii.2012, / T. Dikow’, ' Laphyctis / sp. / det. T. Dikow 2012', USNMENT00832228 & 38 [2♀] & 29 [1♂]' (NMNW); 2♂ 5♀ 'Namibia: Erongo: Namib-Skeleton / Coast National Park, Gobabeb, / Kuiseb riverbed, dry, open, sandy / riverbed, perching on sand, 23°33'35"S, / 015°02'06"E, 389 m, 05.ii.2012, / T. Dikow’, ' Laphyctis / sp. / det. T. Dikow 2012', USNMENT00832216-17 [2♂] & 10, 20, 22, 30, 37 [5♀]' (USNM); 2♂ 'Namibia: Erongo: Namib-Skeleton / Coast National Park, Gobabeb, Kuiseb / riverbed, perching on sand, 23°33'47"S, / 015°02'22"E, 396 m, 06.ii.2012, / T. Dikow’, ' Laphyctis / sp. / det. T. Dikow 2012', USNMENT00832215 & 18' (USNM); 1♂ 'S. W. Africa (23) / Homeb [c. 23°38'12"S, 15°10'55"E 445m], 10 mls. / ESE. Gobabeb / 23 –25.i.1972’, 'Southern / African Exp. / B.M. 1972 –1’, ’NHMUK010624220’ (BMNH); 1♀ 'S. W. Africa (23) / Homeb, 10 mls. / ESE. Gobabeb / 23 –25.i.1972’, 'Southern / African Exp. / B.M. 1972-1', ' Laphystia / gigantella Loew / det. H. Oldroyd 1973 ’,’NHMUK010624219’ (BMNH); 1♂ 'Namibia: Erongo: Namib-Skeleton / Coast National Park, Homeb, on / dune, perching on sand, 23°38'34"S, / 015°10'55"E, 445 m, 06.ii.2012, / T. Dikow’, ' Laphyctis / sp. / det. T. Dikow 2012', USNMENT00832221' (USNM); 2♂ 'Namibia: Erongo: Namib-Skeleton / Coast National Park, Homeb, Kuiseb / riverbed, perching on sand, 23°38'34"S, / 015°11'21"E, 430 m, 06.ii.2012, / T. Dikow’, ' Laphyctis / sp. / det. T. Dikow 2012', USNMENT00832219 & 26' (USNM); 1♂ 2♀ 'Namibia: Erongo: Namib-Skeleton / Coast National Park, Homeb, Kuiseb / River, dense, sandy riparian woodland, /perching on sand, 23°38'24"S, / 015°10'57"E, 431 m, 06.ii.2012, / T. Dikow’, ' Laphyctis / sp. / det. T. Dikow 2012', USNMENT00832223 & 24 [2♀], 25 [1♂]' (USNM); Otjozondjupa: 1♂ 'Okahandja [c. 21°58'19"S, 16°54'23"E 1354m]. / 2 –18.iii.1928.’, 'S. W. Africa. / R. E. Turner. / Brit. Mus. / 1928 - 178', ’NHMUK010624227’ (BMNH); Khomas: 1♀ 'Namibia 29.iii.1984 / 26 km N Windhoek. Road / 1/6 22 20'S:17 04'E [c. 1465m] / Londt & Stuckenberg / Dry stream bed Acacia / riparian woodland’ [NSMA-DIP-07855].

Other material examined

(without type status). Namibia: Omasuti: 1♂ 'Otjimbumbe [c. 17°24'S, 14°13'E 780m] / Kunene R. [river] / Mar. 1923' ~ 'S.W. Africa / Mus. Exped.' ' Laphystia / ( Laphystiella ) / gigantella / ♂ Lw’, ’SAM-DIP-A007990’ (SAMC); 1♀ 'Epembe, 7km NE at / 17°33'S, 13°35'E [Epembe c. 17°47'13"S, 16°27'19"E 1121m] / Kaokoland / 12 Feb.' (NMNW);

Kavango: 1♂ 'Namibia: Kavango / 10km S Rundu / 18°00'S, 19°41'E / 12 1 1993 / E. Marais’ (NMNW); Kunene: 1♂ 'Khowarib Schlucht / 19°18'S; 13°55'E / Kaokoland / 22-26 Feb. 1985 / J. Irish, H. Rust’ (NMNW); 1♀ 'Hoanib River [c. 19°28'08"S, 12°45'52"E 12m] / Skeleton Coast Park / 6 April 1979 / S. Loew, R. Wharton’ (NMNW); 2♂ 'SWA / Delhi [Farm c. 20°20'36"S, 15°43'43"E 1008m]/ 2015 BC / Outjo / 15 iii 1979 / VB Whitehead’, ’SAM-DIP-A007991’ (SAMC); Erongo: 2♂ 3♀ 'Gobabeb [c. 23°33'37"S, 15°02'26"E], 2-9.ii.1970, E. Lindner’, ‘AAM-011008–011012’ (SMNS).

Other material not examined

(without type status). The following material is believed to represent additional records for eremia sp. n. Namibia: Omasuti: 1? Otjimbumbe, Kunene R., 1923/03/01, SWA Museum Expedition (SAM-DIP-A014438); Kunene: 3♂ 6♀ Hoarusib [River] Otshu [= Otjiu c. 18°13'49"S, 13°16'25"E 743m], 1925/03/01, SAM Expedition (SAM-DIP-A007988); 1♂ 2♀ Warmbad [= Warmquelle c. 19°11'S, 13°49'E 635m], Kaokoveld, 1925/02/01, SAM Expedition (SAM-DIP-A007989); 5♂ 4♀ Cayimaeis [?], 1925/03/01, SAM Expedition (SAM-DIP-A007987); Erongo: 1♂ Kuiseb Canyon, Gamberg foothills, 4-V-1972, E.A. Ross (COEF).

Distribution, biodiversity hotspots, phenology and biology.

Widely distributed in Namibia with a single record from southern Angola (Fig. 56). A commonly collected species over a long period of time (Table 1). Not known to occur in any biodiversity hotspot. Collected from December through to April (Table 2). More recently collected specimens have been found resting on sandy surfaces in dry river beds or on dunes, often associated with habitats described as Acacia Woodland. The Otjiu (18°13'49"S, 13°16'25"E) locality apparently harbours both L. eremia sp. n. and L. orichalcea based on two collecting events in 1985 (late February) and 1929 (early March), respectively. There are two prey records both collected at the Kuiseb River near Gobabeb and pinned with a small homopterous bug ( Cicadellidae , 1♀ NMSA-DIP-71776) and with a female Orthactia gobabensis (Lyneborg, 1988) ( Therevidae , 1♂ USNMENT00832215).