Fly Fishing for Trout Home
User Password
or register.
Scientific name search:

Mayfly Species Baetisca laurentina (Armored Mayfly)

Pictures Below
This Midwestern species is responsible for all my Baetisca fishing experiences. Read the section on the genus Baetisca for most of the details.  

Where & When

Region: Midwest

This species is very important in parts of northern Wisconsin. In Mayflies of Michigan Trout Streams, the Leonards report that the nymphs are locally abundant in Michigan, but they did not find the adults in fishable numbers.

Pictures of 18 Mayfly Specimens in the Species Baetisca laurentina:

Specimen Page:123
Baetisca laurentina (Armored Mayfly) Mayfly NymphBaetisca laurentina (Armored Mayfly) Mayfly Nymph View 3 PicturesI took a few group picture of a bunch of Baetisca laurentina nymphs to show the degree of individual variation in size, color, and shape that can occur within the same species in the same pool of the same river. This variation is one important reason why trout are forgiving of some small degree of variation in our imitations--the naturals themselves vary, too.
Collected March 1, 2004 from unknown in Wisconsin
Added to by Troutnut on January 25, 2006
Specimen Page:123

1 Underwater Picture of Baetisca laurentina Mayflies:

There's a very well-camouflaged Baetisca laurentina mayfly nymph resting on the twig in the bottom left corner of this picture. Can you spot him?  In this picture: Mayfly Species Baetisca laurentina (Armored Mayfly). From the Namekagon River in Wisconsin.
There's a very well-camouflaged Baetisca laurentina mayfly nymph resting on the twig in the bottom left corner of this picture. Can you spot him?

In this picture: Mayfly Species Baetisca laurentina (Armored Mayfly).
Date TakenApr 24, 2004
Date AddedJan 25, 2006

Recent Discussions of Baetisca laurentina

An important hatch 2 Replies »
Posted by Troutnut on Jun 26, 2006
Last reply on Apr 8, 2013 by Willy
Based on reports from several sources and my own experiences, I'm beginning to think it is significantly more important than it has been credited for. The duns emerge by crawling out onto land, so they aren't important, but some of my most memorable fishing nights of 2005 were due to Baetisca spinner falls.

It is a tricky hatch to detect. I haven't seen more than a couple of their spinners in the air at a time, though some of my friends report spotting their swarms. Normally for me they just showed up on the water from unseen swarms upstream. They were mixed with spinners from Ephemerella invaria and Maccaffertium vicarium, among others, but the fish were relentlessly selective to the Baetisca laurentina spinners.

I wasted the better part of an hour flinging a sulphur imitation the first time I encountered a Baetisca fall. Like Ephemerella spinners, they can be hard to spot on the water, and they were much more sparse. I finally captured one, noticed the very different body profile, and since I didn't have anything remotely imitating it I continued to catch no fish. I returned the next night with an imitation with a robust, opaque body, and the fish went crazy for it.

I just finished reading through the account by Caucci and Nastasi in Hatches II about how the extremely important Ephemerella invaria sulphur species went unnoticed for decades because it was confused with Ephemerella dorothea. The maddening difficulty of some dorothea hatches was partially explained away once people understood this difference.

Although Baetisca is much less prominent than Ephemerella invaria, I suspect it has similarly been confused with well-known sulphur species in the rare locations and occasions where it is important.
ReplyCan't wait to hit this hatch
Posted by Troutnut on Jun 12, 2006
It sounds like the Baetisca hatch is really going on here in northern Wisconsin now. I've heard reports from more than one source about fishable Baetisca laurentina hatches on two of my favorite rivers. I bought some imitations and hopefully I'll be using them tomorrow!

Your Thoughts On Baetisca laurentina:

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

Username:          Email:

Password:    Confirm Password:

I am at least 13 years old and agree to the rules.
Top 10 Fly Hatches
Top Gift Shop Designs
Top Insect Specimens
Miscellaneous Sites