During the last two years a garrulous flock of sparrows have bullied visiting swallows and martins out of their nests on the eaves of my house. Even wintering roosting wrens are not made welcome. Padraig Ó Caoimh Newtown, Co Waterford
One way to discourage flocks of sparrows is to limit the availability of the food they like. As they feed on the ground, use wire-mesh nut feeders rather than open feeders and avoid small seeds.
In a wooded area near Rathcormack, Co Waterford, I spotted an insect two or three inches long, with a yellow and black body, a spike on its end, and yellow legs. Is it an Asian giant hornet, as pictured in the Daily Mail? Terry O'Brien Baltray, Co Louth
No. It is a harmless sawfly – the horntail, also called wood wasp (Urocerus gigas) – which is found in pine woods. Yours is the female, as she has an ovipositor with which she bores into trunks and deposits her eggs. These take two or three years to mature.
Kevin Nolan of Castleknock sent a photograph of the black and yellow brindled hoverfly notable because of the vertical lines on its thorax.
Michael Viney welcomes observations at Thallabawn, Carrowniskey PO, Westport, Co Mayo, or by email at viney@anu.ie. Please include a postal address
