Category Archives: entomology

Hexagenia Mayfly responsible for polluting the Great Lakes, Asian Carp rush to the rescue

Hex_Hatch In an interesting turn of events it appears the Hexagenia mayflies of Lake Erie may be blamed for polluting the lake.

… nasty little buggers, those …

In a similar experiment, Chaffin found that a burrowing mayfly can kick up buried phosphorus. Once that phosphorus is back in the water, it can fuel more algae blooms.

“There is an effect,” Chaffin said “I don’t know if it’s just a drop in a bucket, or if it is a main reason why we’d be seeing these blooms come back since mayflies have come back.”

Even if the return of the mayflies has contributed to the resurgence of algae blooms and low oxygen, it’s not a sign that Lake Erie managers need to kick the bugs back out.

“It’s not necessarily the mayflies’ fault that there’s so much phosphorus in the sediment,” Chaffin said. “The mayflies are going to do their thing if there’s a lot of phosphorus or not.”

Water managers are less than concerned as they know the arrival of the Asian carp will ensure those pesky mayflies get their comeuppance in spades.

… it’s the cheaper alternative to dismantling the electric fish barrier, boosting the voltage and dragging it along the bottom to zap hidden mayfly terrorist cells.

“I grew up on the shores of Lake Erie, so I remember there being no mayflies,” he said. “So every time I’m wiping mayfly guts off my feet, I don’t get too upset about it.”

Tags: Great Lakes, Asian Carp, Hexagenia Limbata, algae bloom, phosphorus sediment, mayfly burrow, fly fishing humor

109 Seconds to make you an entomological genius, and the toast of the Office XMAS Party

Only 109 seconds to master both human nature and entomology. You’ll master aquatic, terrestrial, learned behavior – and be able to relate to your children as never before.

No need to thank me, it’s what I do …

Warning: Don’t drink coffee while watching, it may come out of your nose.

… and all my taxpayer dollars were spent on, “Just Say No?” For the price paid we could’ve exhumed Walt Disney, brought him back to life, and been in syndication by now.

Tags: Spiders on drugs, YouTube, entomology, Walt Disney, Crack Spider’s bitch

Singlebarbed Reviews the Ultimate Stocking Stuffer: The New Scientific Angling, Trout and Ultraviolet Vision

With our faddish nature I’m always surprised fishermen aren’t more fashion conscious. Our weakness has always revolved around something new as a wholesale fix for all our fishing ailments.

In the Eighties it was Polypropylene – lighter than air and a couple of turns on a hook shank would make a fly float all day. The Nineties were typified by gummy latex and a veritable flotilla of eye catching synthetics.

The last decade was dominated by pearlescent, opalescent, and oily duck’s arse – and the renewed promise that only a couple strands would make a fly unsinkable.

Now it’s the Ultraviolet spectrum and every vendor is hell-bent on squirting chemicals we can’t detect (and of dubious UV qualities) on everything from salmon eggs to dry fly hackle, claiming the “fish killing qualities of the ultraviolet are virtually infinite.”

… and in all this frenzy, Reed F. Curry’s book –  “The New Scientific Angling, Trout and Ultraviolet Vision” makes it’s debut.

FrontCover3in

Reed’s task is Herculean. Bring the stuffy lab-coated world of ocular physics out of its chaste mathematical surroundings, remove the obfuscation of scientific jargon, and adapt the material for fishermen, then drop the polished treatise onto the coffee table – there to compete with Playboy, People, and Guns N’ Ammo.

It’s a singular work, and his timing is impeccable.

Those of you familiar with The Contemplative Angler recognize that Reed’s quiet and biting humor is a common thread throughout his work; how he could remain stiff-lipped and scholarly was surely going to be a trial … and I was pleased he failed … miserably.

The book is reminiscent of a High School science text with the salient points highlighted by color in the margins. In this case, Reed spills both wit and angling reality into the colored boxes, a clear demark between the Science and Angler-humorist.

Fly tiers will read it like Playboy. Pictures first and text second – and the concepts of UVA (Ultraviolet absorption), UVR (Ultraviolet refection), and VIS (visible light) are featured in multiple pictures per page – which keeps the scholarly segments easy to absorb and engaging.

There is an enormous amount of real meat for the angler, and the segment of greatest interest to me was the discussion of “pattern matching” that answers that most elemental of all questions, “Why do fish think this is food?”

As the Quill Gordon floats within the trout’s range of vision – and here I am going to avoid the complex issues of Snel’s Circle, reflection and refraction and simply assume that the visual sensory input is very detailed and complete – the trout’s brain receives input of the fly exactly as it appears from below, in the full trout spectrum. VIS and UVR. The trout brain now gathers the elements that are attached to each other – hackle, body, wings, tail – ignoring floating particles of foam nearby, and assumes that it forms the whole unit. Against this gestalt the trout brain uses pattern matching, just as we would. The order of conditions is presumably the same:

  • First, check for danger. Is the object a known threat? “No.”
  • Next , check for food. Is the object a food item? “Yes,” “No,” “Maybe.”

And that is the crux of it. If as anglers we can establish “Maybe,” we have won the first part of the game. “Maybe” can indicate insufficient information which may lead to further investigation through other trout senses – Taste and Touch. In order for the fish to touch and taste, he takes an object in his mouth, hands being in short supply.

The section on “the composite insect” and how it fits into a fish’s pattern recognition “database” is enough to send any fly tyer into a reproductive frenzy.

Schweibert, Flick, and Swisher & Richards all gave us wonderful tomes about mayflies, most with wings intact and inviolate. Reed suggests that the all important “Maybe” that spurs trout to eat – may lie in the thousands of images of mayflies (caddis, etc) stored in memory.

Crippled, in the water and out, half in, struggling, fluttering, landing – double the images to account for the broadside view, quadruple that to take in the fore and aft of all the above, and you quickly get to millions of possible watery lumps that “maybe” food.

Which is why those old archaic flies we know don’t work like the McGinty, the Royal Coachman, and the Trude – all non-scientific flies, get eaten, and often.

“The trout’s pattern for mayfly wings, therefore, must be quite vague, perhaps simply a small extension from the body, light in color and displaying a hint of UVR. A trout that only eats mayflies with perfectly formed wings is missing a lot of food.”

As humans we view insects and their imitations with only the visible spectrum (VIS). Fish can use both visible and UV light to recognize prey, and at depth or during low light conditions where both are active, a mixed image is likely.

“Through UVR in combination with VIS, trout have an opportunity to see fine details of the chitin, the outer surface of an insect’s body and wings. How deep this vision goes depends, of course, on the individual trout, the conditions, and the insect.

… (trimmed by KB)

So, surface texture is significant because, despite what we see with our more limited vision, the trout can detect in the UV that natural flies are not perfectly smooth.”

The book’s photography covers the full gamut of angling gear as well as specific sections dealing with insects, fly tying materials, and the UV signature of colors in general.

Baitfish get some UV love as well. Rather than pile on more UV materials onto a hook shank – knowing which components of smaller fish are most visible in the UV spectrum suggests a thoughtful placement of materials – versus the “more is better” broad paintbrush.

… and while Reed answers more questions than he poses, it’s plain that both vision and perception suggest there is a great deal of unexplored territory left in the classic stalk and seduction of trout – and any other UV equipped gamefish.

This is a wonderful reference work for all anglers, likely to turn some of your notions about fly fishing on their ear. Careful study of the colors and their qualities under UV will assist in fly selection, clothing choice, and fishing qualities like retrieve and how depth may play into fly selection.

… and for the fly tier the color plates alone justify inclusion into your reference library. An essential book if you’re attempting to navigate the vendor offerings and add UV aids in insect imitations.

Me? My next fishing vest will be Bright Yellow … waders painted with a similar retina scorching disjointed color pattern – a not so subtle mix of the Bismarck and Elvis.

Pikeminnow rolling lazily between my feet as I’m completely invisible …

Amazon lists the book at $27.95, with only two copies left. Jump on it.

Full Disclosure: Singlebarbed did trade two (2) pairs of Sixth Finger Scissors to Messr. Curry for the privilege of owning such a superb reference work. Tears were involved … his mostly.

Tags: Reed Curry, The New Scientific Angling Trout and Ultraviolet Vision, Overmywaders.com, The Contemplative Angler, trout vision, ultraviolet spectrum, visible light, baitfish, insects, fly tying materials,

Meet the Savior of the Brown Water, the Oil Spill Gordon

Thraulodes_Quevedoensis There’s a certain contentment knowing coarse fish will be around to confuse and entertain future generations of fly fishermen. They’ll be speaking with the same awe of “Silver’s”, “Grass”, and “Common’s” that we’ve reserved for Brown, Brook, and Rainbow.

… and while they’ll continue to siphon mud for hints of protein, we’ll still be able to gear up for dusk and the traditional hatch of dry flies…

thraulodes_nymph All those Catskill dries will have long vanished into antiquity, replaced by the Savior of the Tainted Water, the Thraulodes quevedoensis.

Discovered this year in Ecuador, the Thraulodes Mayfly appears to be pollution insensitive and thrives on concrete, human waste, and radiation.

United States protocols assume mayflies collectively are indicators of high water quality, but the Thraulodes quevedoensis signals that the assumption might not be entirely true in the lowland tropics of South America.

Flowers offered his theory on why this species of mayflies is able to tolerate the polluted conditions of the river, which gets sewage directly from the city and agricultural pollutants from farms upstream.

“During the wet season, the river gets torrential rains from the Andes Mountains,” he said. “During the dry season there are shallow spots in the river and algae grows. This can act as a purification system, and I believe this can keep the pollutants below critical level.”

The flies of tomorrow may sound similar, but us brownline types thrive on a hint of humor mixed with a leavening of pure insouciance, evidenced by our lust for the Fan Winged Corn Niblet, the Light Twinkie, and Oil Spill Gordon.

… the Bad News is future generations will be just as pissed, especially when their savior sports a 5.6mm body length … an #18 if they’re lucky …

Tags: Thraulodes Quevedoensis, pollution insensitive mayfly, Equador, Dr. Will Flowers, Catskill dry fly

We’ve struggled to explain senses we lack, can motion convey both form and identity?

Water waves Science suggests there is more to the lateral line than we’ve suspected and may provide more than mere vibration detection.

An interesting mix of attributes we’ve always thought fish had – and new information that suggests it may detect form and assist in the recognition of prey.

“The lateral-line system is a unique mechanosensory facility of aquatic animals that enables them not only to localize prey, predator, obstacles, and conspecifics, but also to recognize hydrodynamic objects. Here we present an explicit model explaining how aquatic animals such as fish can distinguish differently shaped submerged moving objects. “

The authors present evidence in the form of heady mathematics which is completely offputting despite my math background, and my posts are unable to display mathematical symbols – requiring me to interpret the theorem with English…

First, a faithful shape recognition is only possible if the distance, D (is less than but approximately equal to) the submerged moving object’s body length, B; here, B (is approximately) 5 cm. Second, localization of the submerged moving object (SMO) is possible within a distance comparable to the length of the detect-ing lateral-line.

The above suggests that a baitfish could be recognized by a hungry 30” Striped Bass at a distance approximately the same as the Striper’s length. “Recognized” is the the human term describing the new stuff we don’t know and can’t describe. It’s possible that the frantic swimming of the bait may create a disturbance that registers with the predator’s lateral line from a greater distance – but it’s unable to “know” what made the motions.

It would seem that larger fish can detect (identify) motion-based food further away than smaller fish due to the increased length of its lateral line. It may partly explain why smaller fish rush forward to take the fly, they can see/feel it but can’t recognize it as food and need to close with it before identification is complete.

… and as they’ve already spent all those precious calories getting there first – why not give it an exploratory bite …

The real question is whether we’re only matching half the hatch. Silhouette and color are certainly part of the mix, but how much does the violent swimming motion of a dislodged Stonefly alter a fish’s perception of both the natural or its stiff imitation?

When drunk, humans can be coerced into sampling a two dimensional cardboard replica of a hamburger in part because it tastes identical to its three dimensional cousin, yet unimpaired they eat it anyways recognize it as inedible even at distance.

Makes an interesting thought to ponder. We’ve always seen motion of the fly or bait as part of the overall presentation. There’s not a great deal we can do other than pull it towards us fast or slow or add some device like tungsten beads or wiggle legs.

If the fly is presented upstream will the “dead drift” be as effective as the yanked fly as there’s less lateral line to engage – or should we present streamers broadside to the lateral line – giving us an even better chance of detection?

… and while I sort out all this new information should I be carving my caddis nymphs out of Gummy Worms as their gooey freshness resonates at the same pitch as a caseless Hydropsyche in full mating rut?

We allowed bobbers so long as we called them something different – and a Gummy Bear is artificial … Can the fly fishing world survive single, barbless, and sugary?

Tags: Lateral line, fish senses, gummy bear, stonefly, motion sensitive, fly fishing,

Susan’s Purse Making Caddis, ten toes on the fender

Us Anglers have always been linked with conservation issues. Often we’re the whistle blowers that link some abusive practice with its effects on riparian habitat.

Invasive species and our part in spreading them was a stiff jolt. We’ve had the luxury of being the “Good Guys” for so many years – finding out we are the cause of some malady is a bit uncomfortable.

Giving up felt soled waders may be martyrdom to some, but as the pristine environments shrink, what else are you willing to part with?

Oh yes, it’s coming to that.

Those that made the pilgrimage to Hat Creek when reopened after its makeover by CalTrout have fond memories of large fish, Green Drakes, and the Powerhouse #2 riffle lined with enormous October caddis cases.

They are all gone now and have been for many years.

We did that. All those thunderous feet chasing large fish managed to squash the October Caddis out of the areas accessible to wading anglers. Siltation from the upstream powerhouse and the occasional canal break were responsible for the demise of the Carbon Bridge Drake hatch – but all our feet in the riffle above certainly added to the silt burden downstream – we just never measured the effect.

… and like most “trophy” water – our passion for bigger fish and wild trout has always put a dent in populations – despite our intentions otherwise. Hook the same fish 34 times a year and eventually he gets his gut squeezed, hits a log when dropped, or no longer has enough integrity in his lower jaw to eat mayflies …

We mean well – we’re not bad people, it’s just a numbers game. Thousands of anglers fishing continuously over a small space alters the landscape just like grazing cattle.

… and cleated rubber soles – they will make it easier to destroy the banks – as the same entree and exit points are used by thousands of anglers season after season.

The next couple of decades are liable to make us give up a lot more than felt soles, we may even be banned from certain watersheds – or no longer permitted to wade at all.

Invasive species come to mind, but I’m thinking of the Endangered Species Act and shock of finding some of the best water denied to the Gore-Tex hordes.

This year two species of underwater insect made the Federal Endangered Species list; the meltwater lednian stonefly (Glacier Park), and Susan’s purse-making caddisfly (central Colorado: Trout Creek Spring and High Park Fen) and may result in federal protection for what small areas still contain them.

This has always been a hot issue among private land owners who are suddenly denied use of their property to protect a salamander or lily – and with our big feet stirring up sediment and squashing insects underfoot, we may have to ante-up as well.

It’s certainly an unwelcome thought, yet fascinating to contemplate.

… and while you glance down at them big feet knowing you’re innocent of all wrongdoing – how your gazelle-like dance through the fast water couldn’t possibly be doing harm. Think again. Many thousands of insect lovers you never knew existed will be gearing up to confront you in the parking lot…

… you’ll have one foot poised over the water when you feel the Taser darts bite through your vest.

Tags: meltwater lednian stonefly, susan’s purse making caddis, insect lovers, taser, hat creek, wild trout, big wading feet, CalTrout, Trophy trout, global warming, Endangered Species Act, cleated wading shoes

Rare three tailed stone fly discovered in Manhattan sewer

Fossil Mayfly? Scientists claim the below fossil to be that of a rare mayfly.

I think they spent a couple hundred grand of their parent’s hard earned cash on beer drinking and frat parties  – more, if they have a Ph.D.

Mayfly, my ass – anyone above the age of six knows that’s a stone fly.

Science. We serve it up so you can hate it all over again.

Tags: fossil insect, mayfly, stonefly, entomology

Organic drift – Under the protective blanket of darkness there’s plenty of activity

Placing drift netsIt doesn’t take a Ph.D to notice it’s easier to fish and wade downstream versus fighting the current or moving upstream. Despite our best efforts, fishing upstream is mostly slack management, the line’s pouring towards you at the speed of the current and you’re doing you’re best to keep some small connection with the fly.

If we struggle with two legs, wouldn’t the same be true of critters with six?

Organic drift is an entomological term describing the tendency of aquatic insects to move downstream. Despite their clinging, crawling, burrowing, behavior – once they’re exposed to the current, they’ve all the same issues we do.

In a widely cited paper, Muller (1954) noted an apparent paradox in the downstream movements of insects, suggesting that with the large numbers drifting downstream, one would expect to see a depopulation of upstream reaches. However, this was never observed. He proposed that upstream flights of adult aquatic insects compensated for the downstream movements of the larval forms, thus resolving the apparent paradox. Waters (1972) proposed the ‘excess production hypothesis’, which
suggested that the production of insect progeny was in excess of the stream’s carrying capacity, compensating for the drift (i.e. these drifting insects are ‘extras’). The true explanation is probably a combination of both colonization hypothesis and the excess production hypothesis, and perhaps some other factors. Researchers continue to look for answers (e.g. Hershey et. al. 1993).

Mother Nature knows humans and insects are prone to fits of laziness, and she’s lent considerable help by making the egg laying phase of aquatic insects the winged form. Prevailing theory suggest that adults have a tendency to fly upstream to ensure eggs and nymphs are redistributed throughout the watershed.

CaddisTo us lay scientists it makes perfect sense, at the point the female daubs the water surface with an egg packet, the current assists the eggs to find purchase downstream of the point of impact.

Proving the theory via research has been largely unsuccessful, but there’s a lot of really useful information that could explain fishing phenomenon we’ve witnessed.

A 1964 study of the river Yarty, a chalkstream near Devon, England, suggests areas of bank and stream erosion releases more insects into the water column than solid substrate.

It was found that the more abundant species of the bottom fauna were likewise the most abundant in the drift, with the exception of some common benthic organisms which live in more sheltered niches or have a strong means of attachment.

Anglers are notoriously poor with numbers, but even we know which insects hatch day after day for the bulk of the season. While the time of emergence will change due to seasonal changes in water temperatures and available light, it’s safe to assume a prowling fish will see more of these abundant bugs than anything else.

This verifies some of our “prospecting” theories, if the Blue Wing Olive is the main course – prospecting through the doldrums with no visible fish activity might be best served with … a Blue Wing Olive imitation.

A 1986 study of the Consumnes River in California suggests long pools absorb drifting insects, and unless the pool itself is replenishing the insects, there’s more to eat at the head of a pool that at its tail.

These findings lead us to hypothesize that long pools act as barriers, not filters, to stream macro-invertebrate drift. The composition of drift leaving the pools in this experiment appeared to be controlled by the composition of the benthic habitat at the tail of the pool and not by the composition of upstream drift entering the pools.

Insect drift may also be one of the causes of the “complex” hatch, as many insects (especially midges) will drift en masse during low light or nightfall. Many reasons account for drift, but the low light surge is thought to be a response to visual predators like trout, where the low light increases the chance of survival.

We’ve seen nymphing trout during the evening hatch numerous times, and while emerging insects are present, it’s possible they’re dining on a smorgasbord rather than the hatching insects we can see.

A study in Otsego County, New York, counted drifting caddis over two evenings and found evidence that moonlight depresses the number of caddis in the water column, and of the 152 caught all were members of Caddis families that construct hard cases.

Makes an interesting twist on the theories espoused by practitioners of Czech nymphing – whose imitations are all worm-outside-the-case style.

MayflyMany of these studies show that Midges and Mayflies comprise the bulk of drifting insects, and Stoneflies and Caddis are relatively small in number. This is consistent with what we know of insect behavior, as both midges and mayflies have entire species that are free swimming.

More drifting insects are available in Spring and Summer, correlating studies suggesting increases in water temperature and volume causes a proportional spike in insect numbers.

The obvious question is, if the insects are in part tumbling about looking for the safety of reattachment – and part intentional drift (overpopulation, predation, hostile environment) – what happens when they have a chance to grab bottom again?

Drifting organisms apparently seek actively their places of protection again in the bottom substrates in response to increasing light intensity in the morning, since drift rates decrease sharply at this time (Waters 1962).

One study suggested that all three (mayflies, caddis, and stoneflies) have a tendency to remain drifting at night even with reattachment possible. The species of mayfly observed only sought attachment during daylight, and the caddis only landed on similar fauna – suggesting there’s some type of preference at work.

Studies on how far insects will drift suggest that 50-60 meters per night is not uncommon. The speed and volume of water movement roughly dictates distance.

As drift levels are not uniform – and one section of creek can contain more bugs mid column than another, it’s left to us lay scientists to correlate all the information into a place to stand shivering.

I’ll take failing sunlight on an eroding bank, upstream of a pool, close to dark, on a waning moon. The rest of the creek we’ll leave to the dry fly fishermen who’re fighting over our scraps in the flat water below.

Stoneflies caught doing the nasty chat and you’re a freak for listening

Loosely translated it’s, “I dig the minimalist thing, and your cerci are smoking … call me for acrobatic sex.”

I’m tone deaf so I’ll opt for the TV hearing aid that’ll boost my fading senses – enabling the voyeur. If you’re headed back to the car and I’ve got my ear glued to a tree trunk and give you the wave off – you’d be wise to get take out…

I always wondered how them little buggers outwitted me despite my going to the creek every night. The ones that prefer abstinence are on the hollow hickory as lookouts.

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