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Lateral view of a Male Baetis (Baetidae) (Blue-Winged Olive) Mayfly Dun from Mystery Creek #43 in New York
Blue-winged Olives

Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.

27" brown trout, my largest ever. It was the sub-dominant fish in its pool. After this, I hooked the bigger one, but I couldn't land it.
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Caddisfly Genus Chimarra (Little Black Sedges)

Chimarra aterrima is the most important species.

Where & when

Time of year : Early May to mid-June

The pupae emerge by crawling out onto land.

In 539 records from GBIF, adults of this genus have mostly been collected during June (26%), July (19%), May (18%), August (15%), September (8%), and April (6%).

In 164 records from GBIF, this genus has been collected at elevations ranging from 26 to 8301 ft, with an average (median) of 1240 ft.

Genus Range

Hatching behavior

Time of day : Morning to midday

There are conflicting accounts of the egg-laying behavior of this genus. Gary LaFontaine writes in Caddisflies that they serenely ride the surface in great numbers to oviposit. In Selective Trout, Swisher and Richards say they dive underwater. Their mention is less detailed and I'm inclined to believe LaFontaine, but perhaps some species exhibits each behavior.

Egg-Laying behavior

Time of day: Afternoon

Chimarra females dive to the bottom to oviposit.

Specimens of the Caddisfly Genus Chimarra

2 Larvae

Discussions of Chimarra

Emerger pictures anyone???
5 replies
Posted by Hellgie on Mar 30, 2010
Last reply on Apr 9, 2018 by Gazzer
I would like to see a picture of an emerging Chimarra or a pupa stage before emerging if anyone has one. I am baffled and curious to how and when they change from a yellow/orange larva to a black adult fly. Also, what would be a good emerger pattern for this fly? Lafontaine emerger in what color?
6 replies
Posted by Btopbuckeye on Mar 4, 2015
Last reply on Mar 6, 2015 by Crepuscular
I had a large swarm of black sedges in a size 16 ovipositing today.the females hadvblack wings and body with a green egg sack was just wondering if that is this genus or something totally different
Pupa color?
6 replies
Posted by Frankcoz on Mar 27, 2008
Last reply on Apr 5, 2012 by Entoman
Seems like dead drifting the pupa pattern during the emergence time is a good way to fish this before the adults are on the water.

Does the pupa retain the orange color of the larva or do they have the color of the adult?
bright green?
1 replies
Posted by Phishheaduj on Jan 12, 2009
Last reply on Jan 12, 2009 by Taxon
i recently came across with a bright green one of these. Is that the same or a completely different species?

Start a Discussion of Chimarra


Caddisfly Genus Chimarra (Little Black Sedges)

19 species (Chimarra adella, Chimarra angustipennis, Chimarra augusta, Chimarra beameri, Chimarra buenoi, Chimarra butleri, Chimarra elia, Chimarra falculata, Chimarra feria, Chimarra florida, Chimarra holzenthali, Chimarra idahoensis, Chimarra lara, Chimarra moselyi, Chimarra parasocia, Chimarra primula, Chimarra siva, Chimarra texana, and Chimarra utahensis) aren't included.
Genus Range
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