Nanoculcita kenya, J.G.H. Londt & R.S. Copeland, 2017

J. G. H. Londt & R. S. Copeland, 2017, Nanoculcita, a new genus of Afrotropical robber fly from Kenya (Asilidae: Stichopogoninae), African Entomology 25 (2), pp. 292-301 : 294-297

Nanoculcita kenya sp. n., Figs 1–11

Etymology. Named for the country of Kenya to which the genus appears endemic.

Description

Based on all available material. General appearance as in Figs 1–2 .

Head. Dark red-brown to black, but colour masked by strong silver and orange-gold pruinescence, white and brown-orange setose. Antennae mostly brown-orange with darker terminal style, fine silver pruinose, scape and pedicel fine white setose, style tipped with a spine-like sensory element, segmental ratios (scape (as 1): pedicel: postpedicel: style (segment + sensory element) – 1: 2.5: 6.8: 2.0. Face dark red-brown to black, but colour masked by strong silver pruinescence, profile plane (no gibbosity evident). Mystax shiny white, well developed ventrally, but extending weakly to antennal bases. Frons and vertex dark red-brown to black, but colour masked by strong silver (immediately posterior of antennal bases) and orange-gold pruinescence, fine white setose. Ocellar tubercle largely asetose (2–3 tiny setae found posteriorly), orange-gold pruinose. Postocular (occipital) region dark red-brown to black, but colour masked by strong orange-gold (dorsally) and silver (ventrally) pruinescence. Occiput with a few (c. 6) short, brown-orange postocular macrosetae and many fine, shiny white setae ventrally. Palpi small, two-segmented, fine white setose. Proboscis straight, shiny dark red-brown to black, fine white setose distally.

Thorax. Orange to dark red-brown, strongly silver and orange-gold pruinose, brown-orange and fine white setose. Pronotum dark red-brown, orange-gold pruinose, fine white setose. Mesonotum dark red-brown, entirely orange-gold pruinose, fine white setose except for moderately developed, brown-orange lateral macrosetae (1 npl, 1 spal, 1 pal). Scutellum dark red-brown, entirely orange-gold pruinose, fine white setose along posterior margin (apical macrosetae absent). Pleura dark red-brown to orange, entirely silvery pruinose, brown-orange and fine white setose. Katatergal macrosetae moderately developed, pale brown-orange. Anatergites uniformly strongly gold pruinose, asetose. Legs: fairly uniform light brown-orange, fine silver pruinose, shiny pale yellow setose. Claws black with brown-orange basal parts, longer than terminal tarsomere, gently curved. Empodium orange, straight, shorter than claws but more than twice the length of pulvilli. Pulvilli ( Fig. 3 ) pale yellow, small, about one-third the length of claws. Wing ( Fig. 4 ) length measured from humeral crossvein to tip, breadth at widest level: holotype 4.9 × 1.5 mm, paratypes (means) – males (11) 4.6 × 1.4 mm, females (3) 5.3 × 1.6 mm. Venation: all peripheral cells open except for anterior cubital (cua) which is closed and stalked. Little variation is evident (e.g. R4 may have a tiny ‘spur vein’ basally, M3 may fail to reach wing margin (as in male from N of Garsen)). Veins dark red-brown, membrane unstained, transparent, microtrichose (especially distal cells).

Abdomen. Entirely orange, strongly gold pruinose, fine yellow setose. T1 with a group of c. 6 moderately well-developed macrosetae, accompanied by longer fine setae laterally.

Male terminalia ( Figs 5–7 ). T8 well developed, S8 somewhat membranous and poorly defined. Epandrium approximately as long as wide and compact (entirely lacking division into lobes), tapering slightly distally. Proctiger short, broad, projecting only slightly beyond distal epandrial margin, posterolateral parts projecting ventrally below level reached by lateral margins of T8. Hypandrium subrectangular, almost twice as long as broad in ventral view, distal margin broadly truncate, lateral margins poorly defined. Gonocoxite moderately well-developed bearing relatively short, club-shaped, terminal gonostylus. Aedeagus stout with short, downturned distal tip.

Female terminalia ( Fig. 8 ). Tubular. T8 twice as long as deep in lateral view. S8 extending distally slightly beyond level reached by T9, equipped terminally with small tufts of setae laterally. Acanthophorites each bearing four dorsoventrally compressed macrosetae. Proctiger narrow, projecting beyond S8.

Type material. All collected in Kenya . Note: the Archers Post female listed below was recorded and illustrated by Londt (1979) erroneously as Psilinus cinerascens Wulp, 1899 , a species subsequently transferred to Rhabdogaster Loew, 1858 (subfamily Brachyrhopalinae ).

Holotype: KENYA : ♂ ‘ Kenya , Eastern Prov. / Kiboko Sanctuary / 2.20331°S / 37.71430°E, 925 m [2°12’11.9”S 37°42’51.5”E 925 m]’, ‘ Sweep net, road / next to indigenous / forest 3 Dec 2011 / R. Copeland’ ( NMKE) .

Paratypes: KENYA : 1♀ ‘ Archers Post [0°38’22.5”N 37°40’04.5”E 840 m] / Kenya / 15 Jan 1973 / I. Bampton‘ [A village near the Ewas-Ngiro River and forested Buffalo Springs Game Reserve] ( NMSA) ; 1♂ ‘ Kenya , Eastern Prov. / base of Ukasi Hill / 613 m. 0.82103°S / 38.54443°E [0°49’15.7”S 38°32’40.0”E 612 m]’, ‘ Malaise trap, Acacia / / Commiphora savanna [A dry bushy area – see Fig. 11 in Londt & Copeland 2013] / 5–10 Dec 2011 / R. Copeland’ ( NMKE) ; 1♀ ‘ Kenya E / 202 km E Thika / Sosoma [c. 0°52’44”S 38°40’24”E 500 m] 2010 / Sni ek 3.12.’, ‘ Rhadinus / sp. / det. J. Bozák’ [Possibly a drainage area of Tana River] ( NMSA) ; 2♂ ‘ Kenya, Rift Valley / Prov., Olorgesailie Nat. / Monument , 1.57930°S / 36.44566°E, 982 m [1°34’45.5”S 36°26’44.4”E 988 m]’, ‘ Malaise trap, Acacia - / Commiphora savanna [Seems to be a dry ‘run off’ – some distance from water! ( Fig. 10 )] / 7–21 Aug 2011 / R. Copeland’ ( NMKE ; 1♂ NMSA) ; 1♂ ‘ Kenya, Rift Valley / Prov., Olorgesailie Nat. / Monument , 1.57962°S / 36.44730°E, 979 m [1°34’46.6”S 36°26’50.3”E 982 m]’, ‘ Malaise trap, nr. / Ol Keju Nyiro River [Seems to be near a weak-flowing or even dry stream bed] / 21 May – 4 Jun 2011 / R. Copeland’ ( NMKE) ; 1♂ ‘ Kenya, Rift Valley / Prov., Olorgesailie Nat. / Monument , 1.57962°S / 36.44730°E, 979 m’, ‘ Malaise trap, nr. / Ol Keju Nyiro River / 18 Jun – 2 Jul 2011 / R. Copeland’ ( NMKE) ; 2♂ ‘ Kenya , Eastern Prov./ Kiboko Sanctuary / 2.20331°S / 37.71430°E, 925 m [2°12’11.9”S 37°42’51.5”E 925 m]’, ‘ Malaise trap, edge of / indigenous forest [Habitat could be described as broken ‘forest’ – the area is obviously a drainage area above the Kiboko Dam. ( Fig. 11 )] / 22 Sep – 6 Oct 2011 / R. Copeland’ ( NMKE ; 1♂ NMSA) ; 1♂ 1♀ same data as holotype ( NMKE) ; 1♂ ‘ Kenya S.E. / Tana riv. Prov. / 14 km N of Garsen [2°16’10.1”S 40°06’38.6”E 20 m] / 9.iv.2004 / M Sni ek lgt.’, ‘ Rhadinus / sp. / det. J. Bozák’ [Possibly a drainage area of Tana River] ( NMSA) ; 1♂ ‘ Kenya, Rift Valley Prov. / Tsavo West Nat. Pk. / Riverine woodland , 46 4 m / 2.99615°S 38.45988°E [2°59’46.1”S 38°27’35.6”E 474 m]’, ‘ Malaise trap, bank / of Tsavo River [A proper river bank situation] / 9–23 Sep 2008 / R. Copeland’ ( NMKE) .

In addition there are three specimens that we have not studied personally, but which have been verified by T. Dikow of the USNM. These we also consider to be paratypes. Data supplied are as follows: 2♂ Kenya , at Athi River, 2°38.51’S 38°21.98’E [517 m], R Copeland, 25.x – 1.xi.1999, Malaise, USNMENTO1097384 & USNMENTO1097409 ( USNM) ; 1♀ Kenya, Tsavo East National Park, near Athi River, 2°38.51’S 38°21.98’E [517 m], R Copeland, 14.xii.1998, Malaise, USNMENTO1097414 ( USNM) .

Distribution, phenology and biology. Known from eight main localities in the southeastern parts of Kenya ( Fig. 9 ). The species is known by 13 male and 4 female specimens. It is probably significant that three females were hand netted while the majority of males (9) were collected in malaise traps. This apparent sexual imbalance is not an uncommon phenomenon amongst Asilidae , and has been ascribed to more active flying behaviour of males (see Londt 1980: 276).Females of many asilid species tend to fly for short distances and stay close to the ground while males have more sustained flight and so can be found in the upper reaches of malaise traps where they may be caught. Available data show that adults of N. kenya are probably active throughout the year (no records available for February and March). As its distribution straddles the equator this is not surprising. Using Google Earth and the coordinates provided for specimens, notes on the probable habitats occupied are provided in the list of material above. Photographs of two malaise traps in situ ( Figs 10–11 ) depict the general environment occupied by these flies. It can be characterised as being in either dry, fine soil or sandy soil, in hot areas with marginal rainfall. Sandy soil is found at the river edge in Olorgesailie and Tsavo West. Olorgesailie was part of a large lake that dried up long ago. One trap was set right next to the bank of the seasonal Ol Keju Nyiro river. Another trap was set about 50 m from the river, in a slight depression that probably has standing water for a short while following rains. The Tsavo West National Park site, also in dry savanna, was next to the permanent Tsavo River. The Ukasi Hill site has sandy soil and is not associated with a water course, although a small artificial water impoundment is near the trap site. The Kiboko Sanctuary trap was set between high-water table forest and a wetland area, associated with a spring-fed stream. This area, with fine soil, occurs in an otherwise savanna habitat.

Apart from this information nothing more is known of the biology of the species.

Figures

Fig. 3. Nanoculcita kenya gen. et sp. n. female. Kiboko Sanctuary.Metathoracic tarsus showing reduced pulvilli. Photograph: B. Muller.

Fig. 4. Nanoculcita kenya gen. et sp. n. male. Tsavo West National Park. Right wing. Photograph: J. Londt.

Fig. 9. Nanoculcita kenya gen. et sp. n. Distribution.

Figs 1–2. Nanoculcita kenya gen.et sp.n.female.Kiboko Sanctuary.1, Lateral;2, dorsolateral.Photographs:R. Copeland.

Figs 5–8. Nanoculcita kenya gen. et sp. n. genitalia. 5–7, Male, 14 km N of Garsen; 5, lateral; 6, dorsal; 7, lateral; 8, female, 202 km E Thika, lateral.

Figs 10–11. Examples of malaise trap positions at Olorgesailie Sanctuary (next to Ol Keju Nyiro River) (10) and Kiboko National Monument (11) showing general environmental conditions. Photographs: R. Copeland.