Prochyliza ignifera, Martín-Vega, Daniel, Ebejer, Martin J. & Whitmore, Daniel, 2017

Martín-Vega, Daniel, Ebejer, Martin J. & Whitmore, Daniel, 2017, Out of the South? The first Afrotropical record of Prochyliza Walker (Diptera: Piophilidae), with description of a new species, Zootaxa 4232 (1), pp. 144-150 : 145-148

Prochyliza ignifera sp. nov.

( Figs 1–5, 7–11 )

Type material. Holotype: ♂; label data ( Fig. 3 ) as follows: ALDABRA: / South Island, / Dune Jean-Louis / 13– 20.iii.1968 / B. Cogan & A. Huston // Aldabra Atoll, / Royal Society / Expedition , 1967–68 / B.M. 1968–333 // HOLOTYPE ♂ / Prochyliza / ignifera sp. n. / Martín-Vega, Ebejer & / Whitmore 2016 // NHMUK010241031. Deposited at NHMUK. Paratypes: 10 ♂♂, labelled: General sweeping; / pristine & secondary / vegetation // LA RÉUNION / Ravine des Orangers / 21°06ʹ01ʹʹS, 55°45ʹ40ʹʹE / 31.x.2015, 26 m / M.J. Ebejer // PARATYPE ♂ / Prochyliza / ignifera sp. n. / Martín-Vega, Ebejer & / Whitmore 2016 ; 2 specimens deposited at NHMUK (NHMUK010241418 and NHMUK010241419), 2 specimens in MNHN, 2 specimens in CIRAD (Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Saint-Denis, La Réunion, France) , 2 specimens in NMB ( National Museum , Bloemfontein, South Africa) and 2 specimens in the personal collection of MJE.

Diagnosis. Prochyliza ignifera differs from other species in the genus by the bright orange head (including vertex and postgena), the long ocellar setae (approximately as long as vibrissa), the entirely yellow fore femur and the conspicuously enlarged abdominal spiracles.

Description. Male. Length 3.8 mm. Body shiny bluish-black, with well-developed macro-setae ( Figs 1–2 ). Head higher than long; frons, vertex, gena and postgena bright orange; occiput dark brown; pedicel bright orange; first flagellomere mostly dark brown (partially broken in both antennae in the holotype); arista bare; eye bare, nearly round in lateral view; frons weakly setulose, with four minute fronto-orbital setae, only upper one more clearly discernible; ocellar setae well-developed, approximately as long as vibrissa ( Figs 4–5 ), arising slightly behind the anterior ocellus; medial and lateral vertical setae and postvertical seta well-developed, but shorter than ocellar setae; lunule bare; gena recessed and at deepest part 0.8 times as high as eye; vibrissa strong and approximately as long as ocellar setae; mouthparts yellow.

Thorax shiny bluish-black, brownish at the extreme margins of the sclerites; only episternum and propleuron (including anterior spiracle) yellow, propleuron strongly pruinose; scutum sparsely but more or less uniformly setulose; chaetotaxy: proepimeral, postpronotal and presutural intra-alar setae absent, 2 notopleural, 1 supra-alar, 1 post-alar, 1 postsutural intra-alar and 1 dorsocentral setae, all well-developed ( Fig. 2 ); 1–2 propleural setae; scutellum with transverse rugae, bare and flat, with 2 pairs of marginal setae, apical pair almost twice the length of basal pair and 1.3 times longer than scutellum; katepisternum with a weak seta at posterodorsal corner and about 6 strong setae at ventral corner ( Fig. 1 ); anepisternum sparsely setulose; anepimeron bare; meropleuron entirely pruinose. Wing completely hyaline and veins entirely pale yellow; calypter and haltere yellowish-white. Legs uniformly covered with short black setulae; fore femur, along apical half, with 2–3 dorsal and 3–4 postero-ventral weak setae; coxae, trochanters and femora entirely yellow; fore tibia dark brown, fading to pale brownish-yellow in basal third; hind tibia with an incomplete dark brown annulus on apical quarter; first tarsomere not modified, yellow to dark brown, about as long as combined length of tarsomeres 2 and 3; tarsomeres 2 and 3 yellow, tarsomere 4 partially dark brown and tarsomere 5 entirely dark brown. Mid and hind tarsi completely yellow, except tarsomere 5 yellow to partially dark brown on hind leg.

Abdomen shiny brown with a fine microsculpture of transverse rugae on dorsal surface of tergites; tergites with scattered erect setulae, longer medially at posterior margin and laterally as long as respective tergites; abdominal spiracles conspicuously enlarged ( Figs 7–8 ); sternites 2 to 5 quadrangular and with strong and conspicuous setae, especially at posterior margin; sternite 5 ( Fig. 9 ) slightly wider than sternite 4 and with a broad groove along midline. Sternite 7 ( Fig. 9 ) with a distinct, strongly bent peg-like process. Postabdomen ( Figs 10–11 ) as in other Prochyliza and Piophila ; surstylus greatly reduced, visible only as a small convexity at postero-ventral corner of epandrium; hypandrium relatively large and of complex structure with a median anterior process and dome-shaped central part from where bilateral posterior arms, broadening at their apex, arise; pre- and postgonites heavily sclerotized; ejaculatory apodeme free, lying just anterior to epandrial cavity with clearly visible, although membranous, duct to basiphallus; distiphallus long and convoluted, poorly sclerotized.

Female. Unknown.

Immature stages. Unknown.

Etymology. The specific epithet ignĭfěra (“fire-bearing”) is a Latin adjective in the nominative case, feminine, singular. It refers to the distinctive bright orange head of the species and to the volcanic seamount that gave rise to the Aldabra Atoll, the type locality of the species, and the volcanic island of La Réunion.

Biology. Prochyliza ignifera was collected on a chicken carcass in La Réunion, together with adult flies of the sarcosaprophagous species Musca domestica Linnaeus ( Diptera : Muscidae ), Chrysomya albiceps (Wiedemann) and Chrysomya megacephala (Fabricius) ( Diptera : Calliphoridae ). This suggests that the larvae of P. ignifera could be of sarcosaprophagous habits, like other Prochyliza species and most Piophilidae ( McAlpine 1977; Martín-Vega 2014).

Differential diagnosis. Prochyliza ignifera runs to Prochyliza using the key to Piophilidae genera of McAlpine (1977) and Ozerov & Norrbom (2010). The scutum is uniformly setulose throughout as in all other known Prochyliza species ( McAlpine 1977; Martín-Vega 2014), although the setulae are stronger and rather sparsely distributed. This stronger setulosity throughout the body, the almost entirely bright orange head (only darkened in the occipital region) and the conspicuously enlarged abdominal spiracles give P. ignifera a distinct appearance ( Figs 1–2, 4, 7–8 ). An updated key to the species of Prochyliza is provided below; illustrations for the characters of the remaining Prochyliza species can be found in Martín-Vega (2014).

Figures

FIGURES 1 – 8. Prochyliza spp. 1 – 5, 7 – 8. Prochyliza ignifera sp. nov. 6. Prochyliza nigrimana (Meigen) (♂ from Kinopiastes, Greece, NHMUK). 1. Holotype ♂, habitus in lateral view. 2. Holotype ♂, habitus in dorsal view. 3. Holotype ♂, labels. 4. Holotype ♂, head in dorsal view. 5. Holotype ♂, head in lateral view. 6. Head in lateral view. 7. Paratype ♂ (La Réunion), habitus in lateral view. 8. Paratype ♂ (La Réunion), detail of the abdomen showing the enlarged spiracles (arrow). Abbreviations: ocs = ocellar seta; v = vibrissa.

FIGURES 9 – 11. Male postabdomen of Prochyliza ignifera sp. nov. (paratype from La Réunion). 9. Sternites 5 – 8. 10. Postabdomen in posterior view. 11. Genitalia, lateral view. Abbreviations: bph = basiphallus; c = cercus; distiph = distiphallus; ej apd = ejaculatory apodeme; ep = epandrium; hyp = hypandrium; peg = peg-like process; ph apd = phallus apodeme; prg = pregonite; psg = postgonite; s 5 – s 8 = sternites 5 to 8. Scale bars = 0.5 mm.