Michael Viney responds to readers' queries and observations on nature.
We found a caterpillar. It was about an inch long, slightly hairy, with a yellow stripe down its back and a black horn sticking up from its back behind its front legs. On the sides, each segment is red with a black surround.
Terry Long, Kilmacanogue, Co Wicklow
It was the caterpillar of the grey dagger moth, one of the noctuid moths, the caterpillars of which feed on the leaves of hawthorn, blackthorn, plum, apple, etc.
While fishing on Lough Ramor, Co Cavan, I saw a pure white swallow flying and dipping with other swallows. If this rare?
Tony Coffey, Cabra West, Dublin 7
Albino swallows are rare but have been recorded.
Last year I saw a purple heron near here, and this year I have twice seen three birds.
Erica Wiebe, Lismore, Co Waterford
Purple herons have been reported as single bird sightings in several years over the past couple of decades, mainly in Wexford and Cork, but one year in Clare and Wicklow. This is the first record of three together.
Michael Viney welcomes observations at Thallabawn, Carrowniskey PO, Westport, Co Mayo; e-mail: viney@anu.ie. Include a postal address.