This common name refers to only one class.
These are pretty much always called Insects.
Nearly a million species of insects have been described by entomologists. I have left several of them off of this site, just to save time, but I've tried to include all the main aquatic insects trout eat in North America.
This site focuses on aquatic insects, of which the most important are mayflies (Ephemeroptera
) and caddisflies (Trichoptera
). Stoneflies (Plecoptera
) come in third, a position arguably challenged by the many two-winged true flies of the Diptera
order, which includes midges and craneflies. I've also included some terrestrial (Terrestrial: Insects which live on land and are fed on by trout only when they incidentally fall into the water are known as "terrestrials" to fly anglers, and they're very important in late summer.)
insects which I've found on or near trout streams. Terrestrials (Terrestrial: Insects which live on land and are fed on by trout only when they incidentally fall into the water are known as "terrestrials" to fly anglers, and they're very important in late summer.)
like ants, beetles, and grasshoppers are an important food source for trout in many places, especially during the summer months.
Aquatic insects do not live their entire lives in the water. Instead, they grow for a year (give or take quite a bit) as nymphs or larvae underwater, and then they emerge into air-breathing winged insects for a short while to mate and die. There are many variations on this theme.
The most important aquatic insects for fly fishermen are mayflies, stoneflies, caddisflies, and midges. Mayflies and caddisflies are the most discussed by angler-entomologists, because it's so useful to closely identify them. The behavior of their species guides the behavior of feeding trout, and an angler who understands the lifecycle of a particular species has the upper hand when it's hatching. This is not so important for stoneflies and midges, because their hatching behavior is less variable.
Brachycentrus (Grannoms) Caddisfly Pupa
View 10 PicturesThe green blob contained in this case is a pupa in the early stages of transformation from larva to the final stage we generally picture and imitate. This specimen and several like it were fixed to a rock I picked up, and each one had the front of its case sealed off, protecting the helpless pupa from predation. It's neat to see the insect part-way through such a radical transformation.
It was very hard to extract this thing from its case, so there's a bit of extra goo near the head from where I accidentally punctured it.
Collected April 14, 2007
from in Added to Troutnut.com by on April 22, 2007
Hydropsyche aenigma (Spotted Sedge) Caddisfly Adult
View 18 PicturesThese big caddisflies were tempting trout as they wriggled out of their shucks (Shuck: The shed exoskeleton left over when an insect molts into its next stage or instar. Most often it describes the last nymphal or pupal skin exited during emergence into a winged adult.), while others skated across the water at a medium pace, probably egg-laying.
Collected May 15, 2007
from in Added to Troutnut.com by on May 18, 2007