**Caddisfly Genus Psilotreta (Dark Blue Sedges)**

Mayflies

Caddisflies

Stoneflies

Taxonomic Navigation -?-

Kingdom Animalia (Animals)

» Phylum Arthropoda (Arthropods)

» Class Insecta (Insects)

» Order Trichoptera (Caddisflies)

» Family Odontoceridae

» Genus Psilotreta (Dark Blue Sedges)

Species in Psilotreta
Psilotreta frontalisDark Blue Sedge	0	0
Psilotreta labidaDark Blue Sedge	1	11

4 species aren't included.

Common Name

Match	Common Name
	Dark Blue Sedges

Pictures Below ↓

It pays to learn the quirks of this very abundant and unusual genus. Its hatches stumped Gary LaFontaine for years before he learned their subtleties, prompting him to give the most common species, Psilotreta labida, the nickname "Slap-in-the-Face Caddis."

Where & When

Time Of Year (?): Mid-June to late July

The most important species are found in the East. They often emerge together with the large Green Drake mayflies, Ephemera guttulata, which can be reduced to a masking hatch (Masking hatch: When two types of insects are on the water simultaneously and the trout are feeding on the less noticeable one, the more prominent insect (usually brighter and/or larger but less abundant) is known as a masking hatch.) when these caddisflies are thick.

Hatching Behavior

Time Of Day (?): Evening

Because the larvae gather in large numbers on certain rocks to pupate, fishing the emergence demands unusual tactics from the angler. Gary LaFontaine describes them in Caddisflies:

A hundred or more cases might be stacked in layers on the underside of a particular rock. When the emergence period begins the pupae pop continually from this area. They escape from the cocoon and wash out from under the rock, creating a food line for trout on the downstream side of the pupation site. During the peak evening hours the emerging pupae may create feeding situations in only a small part of the stream. They attract trout into these prime zones (which fly fishermen can find beforehand by searching for the clusters of pupae).

Egg-Laying Behavior

Time Of Day: Evening

The females flop onto the surface and flitter around in a non-stop commotion there until they're through laying their eggs. Trout key on the fluttering insects and reportedly reject still imitations.

Larva & Pupa Biology

Diet: Omnivorous
Substrate: Silt, sand, or gravel
Environmental Tolerance: Prefers cool streams
Shelter Type: Horn-shaped sand and gravel cases

These are burrowing caddisflies, and their cases are extremely strong. They live in the silt, sand, or gravel for most of their lives, where they are not vulnerable to trout. They expose themselves only when they are ready to pupate, when they congregate on specific rocks.

2 Caddisfly Specimens in the Genus Psilotreta:

Psilotreta labida (Dark Blue Sedge) Caddisfly Adult

View 11 Pictures

Region: Catskills

Collected Jun 1, 2007

Added Jun 4, 2007

Psilotreta (Dark Blue Sedges) Caddisfly Larva

View 9 Pictures

Region: Northeast

Collected Mar 30, 2007

Added Apr 2, 2007

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Jargon Defined:

Emergence: The transformation of a nymph or pupa into the adult winged stage of an insect. The term may refer to the emergence of an individual, or the daily or yearly event in which all individuals of a species emerge.

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.

Masking hatch: When two types of insects are on the water simultaneously and the trout are feeding on the less noticeable one, the more prominent insect (usually brighter and/or larger but less abundant) is known as a masking hatch.

Pupae: Any insect which spends most of its juvenile lifetime as a larva first becomes a pupa for a time before emerging as a fully grown adult. Depending on the species, the pupal form can be very important for fly fishermen to imitate.

Useful References:

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

Schwiebert, Ernest G. 1955. Matching the Hatch. MacMillan Publishing Company.

Swisher, Doug and Carl Richards. 2000. Selective Trout. The Lyons Press.