**Caddisfly Species Amiocentrus aspilus (Little Western Weedy Water Sedge)**

Mayflies

Caddisflies

Stoneflies

Taxonomic Navigation -?-

Kingdom Animalia (Animals)

» Phylum Arthropoda (Arthropods)

» Class Insecta (Insects)

» Order Trichoptera (Caddisflies)

» Family Brachycentridae (Apple Caddis and Grannoms)

» Genus Amiocentrus (Little Western Weedy Water Sedges)

» Species aspilus (Little Western Weedy Water Sedge)

Common Name

Match	Common Name
	Little Western Weedy Water Sedge

Pictures Below ↓

This species produces fishable hatches across the West.

I encountered them in mid-August on the Henry's Fork, mating in thick swarms up and down the bank of the Harriman Ranch reach. However, millions of Tricorythodes mayflies found their way onto the water that same morning and it's unclear if the trout were seeing and responding to the caddisflies at all.

Where & When

Region: West

Time Of Year (?): March to October; LaFontaine reports peaks in late June and in September

Preferred Waters: Best in spring creeks

Larva & Pupa Biology

Substrate: Vegetation

Larvae of this species are especially prone to behavioral drift (Behavioral drift: The nymphs and larvae of many aquatic insects sometimes release their grip on the bottom and drift downstream for a while with synchronized timing. This phenomenon increases their vulnerability to trout just like emergence, but it is invisible to the angler above the surface. In many species it occurs daily, most often just after dusk or just before dawn.) early in the season.

Pictures of 1 Caddisfly Specimen in the Species Amiocentrus aspilus:

Amiocentrus aspilus (Little Western Weedy Water Sedge) Caddisfly Adult

View 4 Pictures

Collected August 11, 2018 from the Henry's Fork of the Snake River in Idaho
Added to Troutnut.com by Troutnut on June 12, 2019

Your Thoughts On Amiocentrus aspilus:

You must log in at the top of the page to post. If you haven't registered yet, it's this easy:

Jargon Defined:

Behavioral drift: The nymphs and larvae of many aquatic insects sometimes release their grip on the bottom and drift downstream for a while with synchronized timing. This phenomenon increases their vulnerability to trout just like emergence, but it is invisible to the angler above the surface. In many species it occurs daily, most often just after dusk or just before dawn.

Larvae: Many classes of aquatic insects, such as caddisflies, midges, craneflies, dobsonflies, alderflies, and many more, are known as "larvae" rather than "nymphs" in their juvenile stages. They have mostly soft bodies rather than hard exoskeletons. These insects also advance through a "pupa" stage before reaching adulthood.

Useful References:

LaFontaine, Gary. 1981. Caddisflies. The Lyons Press.