Rust-eating midges

I noticed some large yellow blotches on the leaves of a lords-and-ladies plant, Arum maculatum, today and found they were evidence of a rust fungus, Puccinia sessilis, growing on the under surface. While looking at this under the microscope I noticed some tiny, red fly larvae browsing on the fungi. My friend Peter Chandler says these are almost certainly a species of Mycodiplosis, a Cecidomyid (gall midge) genus. I am going to try and breed some through to see if they can be named to specific level.

There is a delightful book on microfungi by Thomas Brittain published in 1882. Brittain refers to Puccinia sessilis as the wake-robin clustercup, Aecidium ari, and says it was quite rare in the area he covered in north west England and Wales.

'Wake-robin' used for arums is one of those old English terms that are still in wide use in North America but have largely died out here.

Brittain's book is on-line here.