A Review of the Shore-Fly GenusAxystaHaliday (Diptera: Ephydridae) with Description of New Species from Australia, India, and Thailand

Abstract

Axysta austra sp. n. from Australia, A. indica sp. n. from India, and A. nikita sp. n. from Thailand are described. The synonymy of A. americana Clausen with A. nigrifacies (Miyagi) is proposed. The genus Axysta is recorded from the Australasian and Oriental Regions for the first time. Keys to genera in Hyadinini and species of Axysta are provided, as are illustrations of all species.KEY WORDS: Diptera, Ephydridae, Axysta, new species, Australia, India, Thailand Specimens of Axysta are uncommon in collections and perhaps in nature, and discovery of specimens and undescribed species from the Australasian and Oriental Regions was wholly unexpected, especially as the genus was generally known to have a north temperate distribution (Clausen 1983, Mathis and. Describing and otherwise documenting these species within the context of a species review is the primary purpose of this paper. This review was prompted when collections made by Dr. N. Vikhrev in Thailand were made available to us for study and one of the new species described below was discovered.To facilitate identification of the genus, which is generally uncommon, we have included keys to the subtribes and genera within Hyadinini. We are reviewing Axysta rather than producing a more comprehensive revision because Clausen's (1983) thorough revision is largely current and valid for much of the world. His illustrations, which he graciously allowed us to use herein, should be consulted if there are questions about the identification of a species. We are essentially updating Clausen's revision with the addition of new taxa and new locality information.The shore-fly genus Axysta Haliday (1839) currently includes seven species (three new species are added in this paper) that are found in both the Old and New Worlds (Mathis and Zatwarnicki 1995). Although the genus is generally widespread and is now known to occur in most biotic regions except the Afroand Neotropics, the included species have relatively more restricted distributions: A. cesta (Haliday 1833) from Europe, A. nigrifacies Miyagi (1977) from Japan, A. bradleyi Cresson (1930) from the United States, and A. americana Clausen (1983) and A. extera (Cresson 1924) from the United States and Canada.

A second European Axysta species (Diptera: Ephydridae)

“…Terminology is adopted from Cumming and Wood (2017) and the genus-specific interpretations in Krivosheina and Mathis (2010). Numbers of setae refer to one side of the body only.…”

“…9.viii.2014, Brandenburg, Kolpinsee [52,349°N 12,798°E]; 1 f, 12.v.2013, Mecklenburg-Western Pomerania, Peene valley S Trantow [53,967°N 13,200°E];1 m, 26.v.2003, Lower Saxony, Ahlhorner Teiche [52,928°N 8,139°E]; 1 m 1 f, 6.iv.2009, Lower Saxony, Dollart, Dyksterhusen [53,294°N 7,242°E]; 1 m 1 f, 6.viii.2008, Lower Saxony, Elbe valley Jasebeck [53,163°N 11,135°E];1 m, 6.viii.2008, Lower Saxony, Elbe valley Kaltenhof [53,126°N 11,248°E] Remarks. The identification of this species is based on the interpretation of Clausen (1983), which was subsequently adopted by Krivosheina and Mathis (2010). Clausen (1983) designated the lectotype and illustrated the terminalia, which clearly show the relevant identification characters.…”

“…The genus Axysta has only seven valid species worldwide, which were recently reviewed by Krivosheina and Mathis (2010). Records are known from Australasia (1 species), the Nearctic (3 species), the Palaearctic (2 species) and the Oriental (2 species).…”

“…Within the Ephydridae, Axysta belongs in the Hyadinini, Ilytheinae (Zatwarnicki & Ryczko 2014). The larval biology is almost unknown (Krivosheina & Mathis 2010). Larvae of a Nearctic A. cesta were found in a colony of cyanobacteria Lyngbya sp.…”

“…Motivated by the excellent work of Krivosheina and Mathis (2010), I had a closer look at European Axysta, and surprisingly it turned out that two very similar species occur. This paper resolves the identity of the second species.…”