Putting a Name to a Face

On my last fishing trip to the North Ram River I collected two adult stoneflies (Plecoptera: Capniidae) from the snow along the river (see blog post from 25-Oct-2011). I finally had a chance to identify the specimens and although they are both females, their characteristics are consistent with Bolshecapnia gregsoni. While knowing the exact species name will not add anything new to how one would fish this minor hatch (most members of the family Capniidae are similar in appearance and behavior), it does potentially add another piece to the entomological puzzle.

Capniidae – tentatively identified as Bolshecapnia gregsoni

According to Stewart and Oswood (2006) this particular species is endemic to British Columbia, having only been collected from a small handful of locations across southern BC. The nymphs have not yet been described and virtually nothing is known of the biology of this species, although there are hints that this species may be one of the few stoneflies that inhabit lakes. This leaves me with a few questions to be worked out before I can definitively say that the know range of this species can be extended to Alberta: It is remotely possible that the few adults I saw could have been carried into the Ram River drainage by a freak weather event that carried them over the Rockies. There is also a chance that these specimens may not have hatched from the river but instead may have come from a still water habitat nearby. And finally there is the possibility that the specimens are not Bolshecapnia gregsoni – while the female characteristics can be used for species identification in some stoneflies (including Bolshecapnia) it is the male genitalia that usually provide definitive proof.

 All of this is part of why I find the study of aquatic entomology so interesting. Given all that we know, we are still only scratching the surface – there are many species yet to be discovered and of those that are known, their full range and biology are often shrouded in mystery. There is ample opportunity for professional and amateur entomologists alike to add small bits of information to our collective knowledge; another piece of the puzzle – a puzzle so immense and complex that it will never really be finished. It is this tantalizing hint of a mystery to be solved that excites me. I will be out on the North Ram next fall with the goal of collecting more Bolshecapnia adults (and hopefully some males); and with any luck, I will add another piece to the entomological puzzle.

Stewart, K. W. and M. S. Oswood. 2006. The Stoneflies (Plecoptera) of Alaska and Western Canada. The Caddis Press, Columbus, Ohio. 325pp.

Bug Bits

The essence of fly-fishing can be distilled down this: Enticing a fish into believing that what we are offering them is something that they would normally eat, or at least something worth a quick taste. Ours is a sport of imitation; of mimicking, as near as possible, the appearance and actions of the various organisms that swim, crawl and wiggle in the trout’s world. Fly fishing is also a sport of deception – bits of fur and feathers tied to a hook that upon close inspection may at best have a rough resemblance to the food item we are trying to duplicate. Add to this the often selective nature of trout and the seasonal availability of most invertebrates and it stands to reason that knowledge of the habits and biology of the various food items that trout feed on is an important component of the fly angler’s tool box.

Baetis sp. nymph - an example of a simple yet effective fly pattern

The bulk of a trout’s diet is made up of aquatic invertebrates. Trout also eat the occasional small fish, or even the odd mouse or frog – but this component represents less than 1% of the average trout’s food intake. Granted, larger fish are more inclined to target larger food items when available, but even they do not discount the nutritional value in eating sufficient numbers of small bugs (a 200 pound black bear taking the time to tear open a rotten log for a mouthful of insect larvae is another prime example of this).  Aquatic invertebrates are an important link in most aquatic ecosystems; converting energy from green plants, organic debris, and microorganisms into nutrient dense biomass that larger animals are able to capitalize on.  This link not only allows trout to thrive in lakes and streams, it forms the foundation of the sport of fly fishing.

Claassenia sabulosa nymph (Plecoptera) - a common stonefly on some trout streams

So it is with the subject of aquatic invertebrates that our journey into aquatic “entomology” begins. I have put entomology in quotes because in the strict sense, entomology is the study of insects. But in this section (Bug Bits) I will be covering more than just insects – I will also touch on some of the non-insect organisms that trout feed on. My goal is to provide background information over the coming months so that when we begin to discuss current hatches over the summer, we can cover the subject in more advanced terms.