Prochyliza nigrimana Meigen 1826

Prochyliza nigrimana (Meigen, 1826)

Piophila nigrimana Meigen, 1826: 396. Type locality: Germany. Holotype (1 ♀) in MNHN.

Piophila nigricornis Meigen, 1826: 397 syn. nov. Type locality: Germany. Holotype (1 ♀) in MNHN.

Piophila affinis Meigen, 1830: 383 (Hennig 1943). Type locality: Germany. Holotype not found.

Piophila pusilla auct. nec. Meigen, 1838: 360 (Hennig 1943). Type locality: Germany. Holotype not found.

Piophila occipitalis Melander & Spuler, 1917: 65 (Steyskal 1968). Type locality: USA (Illinois). Lectotype (♂) designated by Steyskal (in Ozerov 2003) and paralectotype (1 ♂) designated by Ozerov (2003) in Smithsonian National Museum of Natural History.

Piophila morator Melander, 1924: 85 (Steyskal 1968). Type locality: USA (Washington). Holotype (♂) in Smithsonian National Museum of Natural History.

Piophila privigna Melander, 1924: 86 (Steyskal 1968). Type locality: USA (Massachusetts). Lectotype (♂) designated by Steyskal (1968) and 9 paralectotypes (sex not specified) designated by Ozerov (2003) in Smithsonian Museum of Natural History.

Piophila nigrimana var. nigrohalterata Duda, 1924: 111 (Hennig 1943). Type locality: Germany.

Material examined. 1 ♀ (MNHN-ED3083, holotype): Meigen collection. 1 ♂ (MNHN-ED3082, P. nigricornis holotype): Meigen collection. 1 ♀ (MZLU-97): Sweden, Helsingborg; 14.v.1916 [labeled as P. lundbecki]. 1 ♂ (MZLU-98): Sweden, Raus; 7.v.1946; coll. O. Ringdahl [labeled as P. nigricornis]. 1 ♀ (MZLU-99): Sweden, Kronören; 25.viii.1942; coll. O. Ringdahl. 1 ♀ (MZLU-103): Greece, Crete; 16–17.v.1979; leg. R. Danielsson. 5 ♂ and 5 ♀ (UAH): Spain, Madrid, Lozoya; UTM 30T 436780, 4533579; 1121 m a.s.l.; 05–12.vii.2006. 5 ♂ and 5 ♀ (UAH): Spain, Madrid, Puerto de Navacerrada; UTM 30T 419976, 4519462; 1711 m a.s.l.; 05–12.vii.2006. 5 ♂ and 5 ♀ (UAH): Spain, Madrid, Collado de la Mina: UTM 30T 403507, 4506344; 1710 m a.s.l.; 05–12.vii.2006. 2 ♂ and 2 ♀ (UAH): Spain, Madrid, Villaviciosa de Odón: UTM 30T 419855, 4473962; 540 m a.s.l.; 12–19.iv.2007. 5 ♂ and 5 ♀ (UAH): Spain, Madrid, Villa del Prado: UTM 30T 386567, 4459281; 660 m a.s.l.; 12–19.iv.2007. 5 ♂ and 5 ♀ (UAH): Spain, Madrid, Hoyo de Manzanares: 30T 424771, 4497334; 1020 m a.s.l.; 12–19.iv.2007. 3 ♂ and 3 ♀ (UAH): Spain, Madrid, Lozoya; UTM 30T 436732, 4533732; 1295 m a.s.l.; 12–19.iv.2007.

Redescription based on the female holotype. Length 4.2–4.4 mm. Body shining black, sometimes bluish or brownish. Head higher than long; gena deep in height (Fig. 1 A). Gena and frons, from lunula beyond anterior ocellus, entirely light orange (Fig. 1 A, B), in some individuals dark orange to brownish black (Fig. 1 C, D). Palpus clear yellow, sometimes darkened. Frontal setae very weak, fronto-orbitals absent. Ocellar, inner and outer vertical setae moderately strong; post-ocellars much weaker.

Mesonotum uniformly densely setulose. Notopleural, pre-alar, supra-alar, post-alar, postsutural intra-alar and scutellar setae conspicuous; postpronotal and presutural intra-alars absent. Anepisternum setulose, anepimeron bare. Katepisternal seta moderately strong. Propleuron and meropleuron almost completely pruinose. Wing whitish hyaline, veins yellowish. Calypters and halteres white. Coxae wholly clear yellow (Fig. 1 A; Fig. 4 D), sometimes partially to almost entirely darkened (Fig. 1 C). Anterior femur and anterior tibia dark, except in the base and the apex; anterior tarsi also partially to almost entirely darkened. Anterior femur with 4–6 conspicuous posteroventral setae on apical third (Fig. 4 D). Mid and hind legs entirely yellow; some individuals with mid and hind femora and tibae more or less darkened (Fig. 1 A; Fig. 1 C).

Abdomen shining black. Tergites showing disperse and relatively weak setulae. Sternites 1 to 6 with rounded margins; the anterior margins are more or less emarginated. Ovipositor illustrated by Zuska & Laštovka (1965).

Male. Similar to female, also variable in body colouration. Tergites also showing disperse and relatively weak setulae, longer in posterior margin of tergite 5. Sternites also with rounded and emarginated margins; the posterior margin of sternite 5 is decidedly sinuate (Fig. 2 A, B). Sternite 7 showing a distinct peg-like process strongly bent (Fig. 2 B). Genitalia as showed in Fig. 2 C, with thick and rounded, leg-shaped ejaculatory apodeme. Phallus long, hairy and slender.

Immature stages. Morphology of egg, larval instars, and puparium described by Martín-Vega et al. (2012).

Diagnosis. Both P. nigrimana and P. georgekaplani are the only species of the genus showing an uniform colouration on the frons from lunula beyond anterior ocellus. Prochyliza nigrimana differs externally from P. georgekaplani in the emarginated and rounded margins of the sternites (Fig. 2 A–E; Fig. 3). Moreover, males of P. nigrimana can be distinguished by the distinctive shape of the margin of male sternite 7 and its peg-like process (Fig. 2 A, B).

Remarks. Prochyliza nigrimana shows a wide variation in body colouration which may lead to misidentification, explaining the number of junior synonyms for this species. Therefore, special caution must be taken when using colour characters for species identification.

Séguy (1934) gave an additional synonym of P. nigrimana: Piophila nitida Meigen (sec. typ.). Zuska & Laštovka (1965) considered it as a nomen nudum introduced by Séguy (1934) on the basis of examining a specimen of Meigen’s collection labeled with this name. I have studied that specimen deposited in the MNHN (specimen MNHN-ED3084) and it is actually a female of L. varipes.

Biology. The larvae are necrophagous (Martín-Vega et al. 2012), although they can breed eventually on decaying vegetables and fruit (Duda 1924; Webb & Graham 1956). According to Zuska & Laštovka (1965), the larvae of P. nigrimana had represented a major pest in slaughterhouses, cured-meat factories and poultry farms in Czechoslovakia. Zuska & Laštovka (1965) defined P. nigrimana as an exophilous, eusynanthropic species, although the latter property would not be developed so strongly as in Piophila casei. Indeed, in central Spain, P. nigrimana is the most abundant piophilid species occurring on carrion in less anthropized, natural habitats (Martín- Vega & Baz 2013), but it appears to be practically absent from urban sites, where the two Piophila species are common (Martín-Vega et al. 2011). In central Spain, adults are active from spring to autumn (Martín-Vega & Baz 2013), but larvae have also been collected during winter (Martín-Vega & Baz 2014).

Distribution. Holarctic and Neotropical; described from Germany (Meigen 1826), this is the species of genus Prochyliza with the widest geographical distribution: P. nigrimana has been commonly cited throughout Europe, including Azores and Canary Islands, Middle East and North America (Duda 1924; Hennig 1943; Zuska & Laštovka 1965; McAlpine 1977), as well as South America, where it has been apparently introduced by man (McAlpine 1977; Ozerov & Norrbom 2010).