Mayfly Family Baetidae (Blue-Winged Olives)

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I wanted to share a couple of patterns that have proven very successful over the years (and the last several weeks in particular) when baetids are about. They hale from England where they have been popular for a very long time. Their construction is simple - silk thread, a wing covert or shoulder hackle, bee's wax, and maybe the merest smidgen of natural dubbing on a few of them. No plastic flash, no head cement, just natural materials delicately applied. There's something very elegant in their understated appearance, and boy do they work! Their thin bodies and sparseness ape the baetids perfectly and the hook set is enhanced as well.

Fished dead drift or under a controlled swing with the rod elevated, they can be deadly when the small stuff is awash in the drift. The two patterns below are the Waterhen Bloa and the Snipe & Purple both in the class of wet flies called North Country Spiders. I find them especially valuable for fishing during baetid spinner activity on freestone rivers in the moderate to slow current sections. They also work fishing "under" the hatch of duns. I never know which one they will prefer, nor have I found any increase in catch rate by doubling up on the one they do for that day, so I just tie 'em both on and leave it be.

Size 16 Waterhen Bloa

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Size 18 Snipe & Purple

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Hi Jason! Do you have a picture of the (acentrella-miniature BWO nymph) on the site? I've been fishing them and wanted a better idea of how they look.
Thanks,
Bruce

These are the little creamy guys that hatch profusely on Fall River (CA), causing VERY selective feeding midday at the end of June/early July below the public access. Common name locally is Tiny PMD's which is a misnomer as these are NOT ephemerellids but rather baetids. Their sulfur coloration is what causes the confusion. Fall river runs well under 60 degrees during the Summer so I have my doubts that this (these) genus (genera) is (are) exclusive to warm water. Ernest Schwiebert identifies them when fishing the Paradise Valley spring creeks of Montana with Joe Brooks in one of his books. Makes one wonder if the fairly common reports of PMD's sized 20 and under on our Western spring creeks aren't really talking about this tiny critter.

In England, their olivaceous and larger cousins go by the name "Spur Wing" in honor of the rear projecting spike off the leading edge of the hind wing. They are reported as important hatches. This spur used to be the easiest identifying characteristic separating species of Centroptilum from others in the Baetidae family. Though the generic name has not been done away with, most species of possible importance to fishermen have been scattered among several genera (at least for now) where this unique wing feature is not shared, thus making stream side identification beyond the familial impossible. The only thing that can be known for sure is that species that fit the above description USED to be called Centroptilum, so my comments on this hatch are listed here.

The current upheaval in scientific circles regarding classification due to the contradictions between genetics and Linnaean taxonomy has posed serious problems for us poor fisher folks trying to share information about hatches. Disregarding physically visible attributes as the primary determinant for species classification is very problematic. The promise of bringing us all together by using a common language in describing hatches by their scientific names has been undermined to the point that we are now little better off than when we used common names. This is no better illustrated than when discussing the Baetidae family. Frankly, modern nomenclature makes it virtually impossible to identify members of this family down to the generic level (let alone species) in most cases... unless you have access to a genetics lab.

Previous nomenclature made it easy to differentiate Baetids to the generic level streamside, and it could be done with the help of a little magnification as follows: 1) Small slender bodied mayflies with 2 tails, solid colored forewings, and dwarf horizontally held hind wings with a tiny spike or smooth leading edge - Baetis 2) The same description except for a rearward projecting spur from the leading edge of the tiny hind wing - Centroptilium 3) Same description, except hind wing lacking - Pseudocloeon. Easy... Simple... and important... because these bugs have subtly different behaviors, hatch cycles, habitat preferences, and fishing approaches required. These differences are now scattered amongst each other as well as a host of new generic names. Now It's true that some names have always changed over time but the concept of "a rose by any other name is still a rose" still operated. What's different now is that we are being told by the scientific community to "call some roses, daisies; some daisies, tulips; and some tulips, roses". Forget what they look and smell like, it's the genetics that count.

Ernest Schwiebert in his later writings lamented these changes and refused to use (for purposes of discussion) many of the taxonomic changes occuring. This was because he forsaw they would lead to immense confusion when trying to discuss what we see on the river with each other, and make it practically impossible to correlate our existing body of literature. I think we should follow his lead.