During the autumn of 2001 I was looking for fungi at Newbourne Springs SWT Reserve, east of Ipswich, when I came across a heavily galled specimen of the bracket fungus, Ganoderma applanatum. It is known as the Artists’ Fungus because of its easily scratched undersurface; it was from this undersurface that the galls were emerging. As most Ganoderma species are below knee height it needs determined searching to find this gall. I only found it because it felt funny underneath.

I had no idea what had caused the galls but about six months afterwards I was browsing through an article on fungi, I saw a photograph of this gall identified as the Nipple Gall caused by the Flat Foot Fly, Agathomyia wankowiczii. I was content with this identification and left it at that. However, when reading an article on this gall in the recent issue of ‘Sporeprint’ by the Norfolk Fungus Study group, I realised I had recorded something new as according to the article it had not been recorded in Suffolk. By chance I also found this gall again affecting the same fungus at Brandon Country Park in October 2002. I displayed a specimen at the Suffolk Naturalists Society members evening, but sadly there was little interest in it.

From what little literature I can find on this gall it seems that A.  wankowiczii in its adult stage has only been recorded once in Britain: two flies were seen at Stanmore Common, Middlesex on 17 June 2000. It is suggested that the storms of 1987 may have helped by providing increased numbers of fallen trees for it to grow on. It is strange that only G. applanatum is galled and not other species.

I am sure this interesting gall must be lurking around in other parts of Suffolk and I urge recorders to look out for it and send any records to the SBRC.

Reference

Bull, A. (2002). Flat-footed fly Agathomyia wankowiczii Schnabl, new to Norfolk. Transactions of the Norfolk and Norwich Naturalists’ Society 35: 28-30.

Neil Mahler

© 2003   Suffolk Naturalists' Society