Malacomyia sciomyzina (Haliday, 1833) segnalata per la prima volta in una spiaggia a sabbia fine del Veneto (Diptera: Coelopidae)
Introduction
Coelopidae, more commonly known as kelp flies, is a small family of maritime
true flies with a subcosmopolitan distribution. The larvae, which inhabit mainly the wrack zone of seashore, are important decomposers in beach ecosystems, in that they feed mainly on stranded decaying brown algae. The species of this family are particularly common in cool temperate climates. Only two genera are found in Europe, both belonging to the subfamily Coelopinae, namely Coelopa Meigen, 1830, with two species, and the monotypic genus Malacomyia Haliday in Westwood, 1840, with one species.
The present short note reports the second record ever of M. sciomyzina from Italy, specifically from a Venetian fine-sand beach.
Distributional account
Malacomyia (sometimes placed in Dryomyzidae (Munari and Rivosecchi, 1995, among others)) is a monotypic genus with the sole species M. sciomyzina (Haliday, 1833), which is widely distributed, though uncommon, in most of the European countries and islands facing the Atlantic Ocean and, some of those, also facing the Mediterranean Sea: Azores, Canary Islands, Denmark, France (including Corsica), Great Britain, Ireland, Italy, Lithuania, Madeira, Netherlands, Poland, Russia (European Part), Spain, Sweden (Mathis and McAlpine, 2011, in part). In this regard, it should be noted that France (including Corsica) is not mentioned by Mathis and McAlpine (2011), while it is included in the range of the species in the Fauna Europaea portal (de Jong et al., 2014; last accessed July 2019). In the same web portal, the species is marked as “doubtfully present” in Sicily, according to the checklist by Munari and Rivosecchi (1995), where the species was recorded as M. sciomyzina meridionalis (Rondani, 1868) and assigned to the family Dryomyzidae.
Some comments on the examined material
In Italy, the very uncommon Malacomyia sciomyzina, previously recorded from a small beach of westernmost Liguria (Munari, 2017), is reported herein for the first time from a sandy beach of northeast Italy (Fig. 1), despite the decades-long fly collections carried out by both Prof. A. Giordani Soika and his technician M. Levrini on the seashores of this territory. These collections produced tens of thousands of specimens of Diptera, in a time-span ranging mostly from the early fifties to the mid-eighties. This plentiful material is now sorted and housed in the Diptera collection of the Natural History Museum of Venice. After concluding (June 2019) the sorting at family level of this unworked material, only five specimens of kelp flies were found from catches in the Mediterranean basin, all of them being M. sciomyzina. The first specimen found had previously been reported in the literature (Munari, 2017) and the family was, therefore, formally recorded for the first time from Italy. In that paper, Munari exhaustively discusses about some misinterpreted Italian records from the previous literature. That specimen had been collected by G. Rallo on 5 August 1980 at Balzi Rossi, near Ventimiglia (westernmost Ligurian litoral), in a small sea cave lit by daylight, about ten meters away from the shoreline. Four additional double-mounted specimens, three of which from the same Ligurian catch, were subsequently found among the sorted material. Otherwise, the fourth specimen is a male newly recorded herein from the following Venetian locality and habitat: “Litorale Veneto [Venetian litoral], Alberoni [Alberoni Beach (Lido of Venice)], prime dune, su sabbia asciutta [fore-dunes, on dry sand], 26.iv.1965, M. Levrini”.
Discussion
Considering the strikingly large amount of material collected in the past by Giordani Soika and Levrini on the northern Adriatic beaches, this species appears to be extremely rare on this Italian coast. However, though uncommon in Italy, M. sciomyzina is expected to be found all over the seashores of this Mediterranean country.
Acknowledgements
I wish to express my sincere gratitude to Dr. Marco Uliana (Natural History Museum, Venice, Italy) for his usual courtesy and collaboration. I am also thankful to two anonymous reviewers who provided useful suggestions to a first draft of the manuscript.
References
De Jong Y. et al. (2014) – Fauna Europaea – all European animal species on the web. Biodiversity Data Journal 2: e4034 (doi: 10.3897/BDJ.2.e4034).
Mathis W.N., McAlpine D.K. (2011) – A catalog and conspectus on the family Coelopidae (Diptera: Schizophora). In: Brake I. and Thompson F.C. (editors), Contributions to the Systema Dipterorum (Insecta: Diptera). Myia, 12: 171-205, Pensoft Publishers & North America Dipterists Society, Sofia, Moscow & Washington D.C.
Munari L. (2017) – Nannodastiidae and Coelopidae: two families of acalyptrate flies new to Italy, with description of a new species of Azorastia Frey (Nannodastiidae) (Diptera: Brachycera). Lavori – Società Veneziana di Scienze Naturali, 42: 15-20.
Munari L., Rivosecchi L. (1995) – Diptera Sciomyzoidea. In: Minelli A., Ruffo S. and La Posta S. (editors), Checklist delle specie della fauna italiana, 74: 1-7.