Parydra (Chaetoapnaea) hecate ( Haliday, 1833 )

Stuke, Jens-Hermann, 2025, Taxonomic and faunistic comments on European Parydra Stenhammar, 1844 (Diptera: Ephydridae) with new species from Finland and Jordan, Zootaxa 5686 (1), pp. 49-105 : 83-84

Parydra (Chaetoapnaea) hecate ( Haliday, 1833)

( Figs. 9, 24 , 62–65 )

Ephydra hecate Haliday 1833: 175 ; type-locality: „Holywood in Downshire“ [Britain]; syntype 2♂ / ♀ [NMID, Mathis & Zatwarnicki 1995].

Parydra obliqua Becker 1896: 215–216 ; type-locality: „Karlovac, Kroatien “ [ Croatia]; lectotype ♂, des. by Papp (1979) [ZMB, Papp 1979]—available, invalid: junior synonym ( Becker 1926)

Napaea consors Cresson 1930: 111 ; type-locality: „Ombla Tal, Dalmatia“ [ Croatia]; holotype ♂ [ANSP, Cresson 1930] synonymy by Krivosheina (1989)

Napaea albifacies Duda 1942: 39 ; type-locality: „Wustung b. Habelschwerdt“ [ Poland]; lectotype ♂, des. by Papp 1979 [ZMB, Papp 1979], jr. syn. nov.

Parydra ralloi Canzoneri & Meneghini 1978: 199–200 ; type-locality: „Torbiere d’Iseo (Brescia), il Mulino“ [ Italy]; holotype ♂ [MSNV, Canzoneri & Meneghini (1978)], jr. syn. nov.

Primary type material examined:

1♂ lectotype of P. obliqua in coll. ZMB with these labels: (1) “ Kroatien / 4011”; (2) “ Parydra / obliqua [& illegible signs]”; (3) “ Lectotypus ”; (4) “Zool. Mus. / Berlin ” .

♂ lectotype of P. albifacies in coll. ZMB with these labels: (1) “22 22”; (2) “Wustung / bei Habelschwerdt / I. Duda ”; (3) “albifacies / [illegible sign] ♀ d. D.“; (4) „ Lectotypus “ .

Additional material examined: 286 specimens from Croatia , France , Germany , Greece , Portugal and European Russia with new country records from Cyprus and Georgia: Material: CYPRUS : 1♀, 2.vii.2016, river n Flasou [35,068°N 32,885°E]; GEORGIA : 1♀, 26.vii.2024, Varjanauli [41.785°N 41.955°E] .

Diagnosis: This is a difficult species which can be confused with several other Parydra . Only a combination of characters will reliably distinguish this species. Parydra hecate has black tibiae, strongly marked wings with media m and radius r 2+3 each with a distinct elongated apical brown spot, typically the haltere knob is light, the scutum has white to grey dusted spots at the transverse suture and a medial stripe of light dusting in additional to submedial stripes ( Fig. 24 ), 1 strong prescutellar seta and additional 2–3 smaller dorsocentral setae. These characters can be difficult to see in aberrant, old or recently emerged specimens. Males are additionally distinguished from similar species by tergite 5 being slightly shorter than tergite 4, the phallus having convex lateral margins in dorsal view ( Fig. 62 ) and the lateral margin of postgonite being concave but lacking a notch in dorsal view ( Fig. 62 ). The separation of P. quinquemaculata from P. hecate is currently based on the limited material examined and reference should be made to the characters given in the key.

Taxonomy: The identification of the lectotype and all other original type material (6♂♂, 2♀♀) of P. albifacies shows that the specimens belong to P.hecate as described above and do not show the characters of P. quinquemaculata as postulated by Papp (1979). Therefore P. albifacies should be treated as a junior synonym of P. hecate (syn. nov.).

Parydra ralloi was described by Canzoneri & Meneghini (1978) in their typically brief style without any diagnostic characters. Canzoneri & Meneghini (1983) distinguish P. ralloi and P. hecate only by the colouration of the tarsi that are stated to be "tarsi interamente scuri" (tarsi entirely dark) in P. ralloi and "tarsi almeno in parte giallastrio o giallo-rossicci" (tarsi at least partly yellowish or reddish-yellow) in P. hecate . I have seen several specimens identified by Canzoneri as P. ralloi including four paratypes (cf. material listing) and I cannot find any character either externally or in the terminalia to distinguish P. ralloi from P. hecate . Therefore, Parydra ralloi Canzoneri & Meneghini 1978 should be placed as a junior synonym of P. hecate (syn. nov.).

Distribution in Europe: Widely distributed in Europe and probably becoming more abundant in the south. Surprisingly there are no records from Scandinavia, Denmark or Iceland and records from northern Germany (Mecklenburg-Vorpommern) north to 55°N might mark the northern distribution border. The only record from outside Europe is from Algeria ( Rossi 1988). Some apparent distributional gaps may be the result of problems with the identification of this species.

Biology: Parydra hecate occurs in a wide range of habitats with available water. It has been recorded from both montane and lowland areas. Habitats include the margins of standing water or rivers, both forested and open areas and both densely and sparsely vegetated places. Despite its occurrence in a wide range of habitats this species occurs more locally in Central Europe than other similarly generalist Parydra species. Adults have been collected from February to October and are polyvoltine. Parydra hecate probably flies year-round in South Europe if climatic conditions are favourable. Stigmatomyces trianguliapicalis has been reported to grow on P. hecate ( Rossi 1988, Santamaría & Rossi 1993).

Figures

FIGURES 22–25. Head and thorax of Parydra, dorsal view. 22, P. arctica Clausen & Cook. 23, P. hautalai spec. nov. 24, P. hecate (Haliday). 25: P. mitis (Cresson).

FIGURES 62–65. Terminalia of Parydra hecate (Haliday). 62, dorsal view. 63, hypandrium, maximal expansion. 64, phallus and phallus apodeme, lateral view. 65, hypandrium with postgonite, lateral view; hy—hypandrium; lpha—lateral arms of phallus apodeme; pg—postgonite; ph—phallus; pha—phallus apodeme.