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Emerging Baetis: A UtahOTF Pictorial
The baetis, or 'Blue Wing Olive,' is a fairly common insect across many of Utah's waters. It's provides fish with a tasty meal and fly fisherman with excellent fishing! The baetis has a fairly simple life cycle. There are a lot of interchangable terms for each stage of this cycle, so let's take a minute to clarify them for the sake of learning! - Eggs are also known as ovum. - Nymphs are also known as larva. - Adults are also called duns or scientifically as subimago. - Spinners are also called imago by some purists. If you really want to impress your friends or other fly fisherman using terms like imago and subimago, it's probably best to go the whole nine and understand a little bit of latin. Imago basically means an 'image' or 'likeness.' Sub is a latin prefix which you should recognize that basically means means 'under,' 'beneath' or vaguely 'not quite.' Now you're on your way to being an elite entomologist! I digress... If you've fished for a while, you've undoubtedly seen the baetis in the dun stage. They're fairly easily to identify. If you're a little more hardcore, you may even know what a baetis nymph looks like. These are 2 major stages in the baetis life cycle. However have you ever had the oppotunity to see a baetis emerger? Better yet, have you gotten to witness the actual emergence? Well now is your chance to get a glimpse of what actually happens when a baetis is emerging! Please enjoy! |
Here's your basic immature baetis nymph.
As the baetis nymph matures, the body color tends to darken. This photo was taken moments before this particular baetis began to emerge.
Emergence has begun. Notice the wings clearly starting to show through the split in the nymphal skin? This area is often called a wing case.
The wing case has dialated substantially and the wings are even more visible!
Full emergence! The baetis is shedding its nymphal skin or shuck. This is what an 'emerger' looks like! This portion of the emergence literally took a second or two tops. Yes, I could kill myself for being out of focus here.
Here the baetis has completely shed its shuck, which is still visible below the adult. Note that the wings don't have good circulation yet. This is a dangerous time to be a baetis! It's basically fly or die at this point!
Things are looking up for our baetis. Her wings are unfolding nicely! Note, you can tell that it's a 'her' because of the smaller eyes. Male baetis have very large eyes!
Another great photo of our emergent baetis and her shuck! Once her wings are upright and dry she'll be off to do what baetis do.
Just to complete the picture, here is a female baetis dun. Again, you can easily tell it's a female because of the eyes.
For the purpose of comparison, here is a male adult baetis. Note the much larger eyes! Sorry, I don't know if they can see better!