Laboured Swimmers:
Habrophlebia, Leptophlebia and Paraleptophlebia are the Genera making up this nymph type. In appearance they are quite similar to the Agile Darters except they are a little sturdier, the tails are not fringed and are often set in a very wide arc and the gills are much longer, forked and more slender. These gills are better suited to the slower moving water conditions the nymphs are found in. They are generally dark in colour and as the name suggests poor swimmers, crawling around in weed, reeds and leaf litter. As a result they are not so often available to the fish.

Bottom Burrowers:
The only species in this group are from the Genus Ephemera, the UK’s largest Upwing flies. These are large sturdy nymphs, Cream to Beige coloured with distinctive darker Brown markings. As the name suggests they live in burrows excavated in the fine gravel or silt of the stream bed, they have large mandibles like tusks which they use for digging out these burrows and long feather like gills held over the top of the abdomen which are constantly fanned when in their burrows to move water and provide them with enough oxygen. Once seen it is highly unlikely they would be mistaken for any other nymph type. Mostly they are available to the fish when swimming to the surface to emerge.

The tables below show hatch timetables for all the Upwing insects that hatch in the UK, they are listed by the common name known to anglers and where one common name covers several species these have been grouped together.
The blue background boxes show months where the adult insects are present and the darker highlight areas show rough density of the hatches in each month, although many species are present over a long period of the season hatches in numbers which attract the attention of fish and can potentially make them feed selectively generally only occur for a short period of time.
Click on the common name for each species to go to a page with photographs, more details and links to artificials I use to imitate each species.

This table includes the most important and abundant species on the rivers I fish in Scotland.

This table makes up the remainder of the UK species, some of them could be very important in your area, the Danica Mayfly being the obvious example. While some of these species are present in Scotland it is only in localised instances or on stillwaters where they achieve anything like the hatch density of the species in the first table.