Halocladius variabilis (Staeger, 1839) (Insecta: Chironomidae) from the rocky intertidal zone of Galway Bay

Marine intertidal insects are poorly documented globally, and Ireland is no exception. The most abundant of these species, and the most widely studied in the North Atlantic, is the chironomid Halocladius variabilis (Staeger, 1839). Here we provide an account of this species in western Ireland based on autumn collections of larvae from the marine intertidal zone of Galway Bay. H. variabilis has a Holarctic distribution, and is known from Hudson's Bay through both eastern and western coasts of cold temperate North Atlantic and into the White Sea (Tarakhovskaya and Garbary 2009). Five species of marine Orthocladiinae, including H. variabilis, are listed in the Checklist of Irish Aquatic Insects (Ashe et al. 1998). There are two reports of H. variabilis from the south coast of Ireland: at Loch Hyne where H. variabililis was associated with algal epiphytes on Himanthalia elongata (Linnaeus) S.F. Gray, 1821 (Kitching 1987), and nearby Sherkin Island, where it was associated with the littoral fringe (Kronberg 1988). One of us (DJG) specifically searched the more typical intertidaJ habitat of Halocladius variabilis in Galway Bay to determine if the insect was represented in this habitat and if it had similar community ecology to our other observations on both eastern and western North Atlantic shores.