The bug aquarium

To thoroughly enjoy fly fishing you need to get totally immersed every once in a while ... Jimmy D Moore

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The aquarium

Setting up the aquarium
1. Place the aquarium (five gallons is plentiful) in a cool place, such as an unheated section of the basement, where it does not get direct sunlight. Day length is important to the life cycle of a bug so some form of artificial light should be provided. A fluorescent bulb is probably the best solution. I'd advise against setting up the aquarium outdoors as you'll have no control over lighting and temperature.
2. Fill the bottom with fine gravel from the river or gravel from a pet store. I prefer the mixed colour pet store gravel because river gravel is generally dark and you won't be able to see the bugs clearly. It is for that same reason that I don't use mud from the river. The gravel needs to have a good depth in order to allow the burrowers, such as dragonflies and craneflies, to burrow.
3. From the river, find light coloured rocks with ledges under which the nymphs can hide.
4. Find light coloured sticks (I use ones that the beavers have chewed on). Make sure they protrude above the waterline so that the bugs can crawl to the top in order to hatch. As a note of interest, it is only the stoneflies, damselflies, dragonflies and hellgrammites that will crawl out of the water to hatch.
5. If possible, secure some river grass or plants in the gravel.
6. Remove any filters from the water pump. The filter will clog up pretty quickly from the sediment in the river water. After the water has settled the filter may be replaced. Stonefly like fast, unpolluted water so make sure your pump is up to the task.
The addition of an airstone at the opposite end of the tank would be most beneficial.
7. Place a screen (such as used in window screens) over the water inlet. If you don't the small bugs will get sucked up.
8. Initially a heater is not required. However, if the temperature in the aquarium is not equal to that of the river (during the warmer months) a heater may need to be installed. For best results the temperature should be between 55F and 65F.
9. A thermometer is required in order to take note of the water temperature as the hatches occur. Whatever that temperature is when they hatch in your aquarium will be approximately the same temperature as when they hatch on the river. Water temperature is probably the most important key to a hatch but bug maturity also plays a part. As an example of this, my aquarium temperature sat at 58F for seventeen days before the early spring mayfly (the Black Quill) hatched. Two days later the exact same hatch occurred on the river when the water had reached a temperature of 55F (the optimum for this particular species).
10. If you're handy with carpentry tools you might want to consider building some kind of cover for the aquarium. I'd lost more flies to the nether regions of my basement before deciding to knock together an A-shaped cover comprising of thin slats and window screen.

Aquarium maintenance
1. Ten to twenty-percent of the river water should be replaced at least every two weeks. This can be combined with siphoning off any rotting vegetation that lies on top of the gravel.
2. Clean off the screen over the water inlet as required.
3. Remove any dead bugs before they gather mould.
4. Blue and brown algae is bad. Green algae is a sign of a healthy aquarium but too much can be suffocating and should be removed.

When to collect bugs
1. It is best to collect bugs early in the year, say March and April. If you wait until the summertime many of the hatches will be over. It's cold work but it's pretty exciting. Continue collecting at odd times throughout the year as you will come across maturer late season bugs.
2. It's worth noting that as time passes the colour of the adult insect collection will change (although the nymphs will generally retain a dark coloured back). The darker adult insects, the black and brown stonefly, the black caddis, and the black quill mayfly, will give way to lighter, more colourful adult insects such as the sulphur duns, light cahills, green and tan caddis, green, yellow and golden stonefly.

Finding and gathering the bugs
1. Bugs can be found just about anywhere but the following are popular places: Mayflies, stoneflies and caddisflies can be found in shallow, riffled, rocky areas of the river. Dragonflies, hellgrammites and craneflies in fine gravel areas. Damsels in weedy, silty areas.
2. I use a large dip net covered in window screen material.
3. Place the net on the bottom of the river and stir up the bottom ahead of the net with your boots. Any loosened bugs will drift into the net.
An alternative and less invasive way (especially for the mayfly, stonefly and caddis) is to buy a large flour-sifting strainer. Place the strainer behind a rock, pick up the rock and swirl it around. Any dislodged insects will drift into the strainer.
4. Get the water for the aquarium at the same time as you collect the bugs. You could also collect the sticks and rocks at this time.
5. You're bound to pick up some mosquito larva, you might want to get rid of them if you spot them in the aquarium.

Bug activity
You'll get a lot of activity when you first place the bugs in the aquarium but then things will settle down. The mayfly and stonefly nymphs will hide under the rocks or on the sticks. The cased caddis will roam all over the place. The sticks seem to be a popular place for the damselflies. The dragonflies will back themselves into the gravel and wait for their prey. The cranefly will burrow deep into the gravel. The hellgrammites will wander or burrow.
A point of interest: You may occasionally find what appears to be an albino-like nymph in the aquarium. This is actually a nymph after it has moulted. Some nymphs moult up to thirty times during their aquatic stage and the time span between moults is called an instar.
Feeding the bugs
1. Well, the dragonflies, damselflies, hellgrammites, craneflies and water beetles will feed on anything that gets in their path (if I had my way I'd keep them separate), so I let nature takes its course.
2. The other bugs can be fed a small amount of regular fish food acquired from the pet store. From what I can see it contains a fair amount of algae and vegetable products.

Bug mortality
1. As I said above, there are several species of predators. One morning I caught a damselfly sucking the life out of a mayfly nymph. Another day I observed a damselfly riding on the back of a small minnow. I have also seen a dragonfly with a spotted sedge in its jaws (in fact all of the spotted sedges disappeared in about five days, although they do spend most of their larva life hidden under rocks). I would certainly recommend a second aquarium just for the predators.
2. The other thing might be the sudden rise in temperature over a short period of time. When I first collected the bugs in mid-April the river temperature was 48F. After about two days the water in the aquarium had risen to 58F. The basement temperature will continue to climb as the outdoor temperature increases, which is all well and good for the later hatches.
3. At the time of the hatch you may observe that some of the flies are short an antenna or a leg or only have half a tail. They sure do take a beating.

Bug identification
This could be a page all unto itself, and as they say, a picture is worth a thousand words. What I would suggest is that you borrow a few books from the library. I have four or five that I refer to when I'm trying to figure out what particular type of bug I am looking at. Three are quite small and can be carried to the river.
They are Trout Stream Insects by Dick Pobst, The Caddisfly Handbook by Dick Pobst and Carl Richards, and Hatch Guide for New England Streams by Thomas Ames Jr. A mid-size book, which I strongly recommend is An Angler's Guide to Aquatic Insects by Rick Hafele and Scott Roederer. Two larger books are Guide to Aquatic Trout Foods by Dave Whitlock and Hatches II (devoted entirely to mayfly) by Al Caucci and Bob Nastasi. And if you really want to get scientific there is a book published by Cornell University called Freshwater Macroinvertebrates of Northeastern North America.
A word of caution: Nine times out of ten the books will agree on bug identification and their common names. It is that one time they do not agree that will throw you for a loop.
A strong magnifying glass will be needed to identify some of the smaller bugs.

In 2013 I was informed of a site that is well worth following. It is entitled Emma's bug blog - an exploration of aquatic insects in the Shubenacadie Watershed

Basic insect identification of the three most important species to fly-fishermen
Mayfly - Ephemeroptera (meaning short-lived winged insect). The nymph has two fairly short antenna, two or three tails, visible gills on each side of the abdomen (the rear end of the body) and wing pads running lengthwise on either side of the thorax (the front end of the body). The adult has large, upright, sail-like wings. It is much, much easier to identify the mayfly adults rather than the nymphs. Check the adults for unmarked, blotched or barred wings and look at the number of tails and the body and leg colours
Stonefly - Plecoptera (meaning folded wings). The nymph has two fairly long antenna, two tails, the gills are located on the underside of the thorax and the wing pads are on top of the thorax. The adult is easily recognizable by the fact that the wings lay flat on top and along the length of the body, extending past the end of the body. When in flight adult stonefly are lumbering and helicopter-like.
Caddisfly - Trichoptera (meaning hair wings). The larva is grub-like, varying in length from 1/4" upwards, the legs and wing pads are located at the very beginning of the body, the rest of the body (or abdomen) is divided into segments with the gills located on the underside. Most commonly seen, and probably the most available to fish, are those with portable cases. The adult is moth-like with tent shaped wings extending past the end of the body. Adult caddis are recognised by their frantic flittering across the surface of the water.

The bug hatches
1. The early black and the early brown stonefly will hatch once the temperature starts to rise, followed by the early spring mayfly. It is quite unlikely that you will see a tiny black caddis hatch as their cases are quite fragile and usually get broken during the collecting process. The hatches should continue, if you have found the right bugs, to follow the hatch chart.
2. Nature has a way of confusing hatch charts by occasionally creating a 'mini hatch' some time before and maybe some time after the main hatch. This is most definitely the case with the golden stonefly. I have found the odd golden stonefly adult in late April/early May and yet I know that the main hatch occurs in June/July. It is thought that this is natures way of ensuring survival of the species.

Photographing the bugs
1. You'll need a camera with a macro lens.
2. Lighting is tricky for an amateur such as myself. A lot of my pictures are taken using the flash or a combination of natural and artificial light. Sometimes I'll overexpose in order to gather more light. A digital camera is perfect for this situation since it allows for numerous photos under various lighting conditions.
3. The aquatic stage of the bugs is fairly easy to photograph, they are usually slow moving or will sit still in the aquarium.
The same cannot be said of the adult stage. They want to fly! It may be necessary to get the adults a little drunk by placing them in a small jar with some cotton balls dampened with rubbing alcohol. You don't want the adults crawling over the cotton balls because they'll get wet and lose their shape. Separate the bugs from the balls by a piece of cardboard or something. Remove the bugs from the jar and place them on a suitable spot for photographing.
Alternatively, if you have the patience and a very clean, clear glass jar, you can do away with the alcohol and wait until the adult settles down and take the picture through the jar.
And yet another way is to simply put them in a jar and place the jar in the fridge.

Preserving the bugs
1. If you wish to preserve the bugs you'll need some airtight, glass vials. They need to be airtight in order to prevent the preservative from evaporating.
2. Ethanol makes for the best preservative. Denatured ethanol, which is 90-95 percent alcohol, can be found in paint stores. It needs to be diluted with water to about 80 percent alcohol. Rubbing alcohol can be used but it tends to make the bugs extremities brittle.
3. Label each jar with details on the type of bug and when and where it was collected.

A word of warning
Make sure you tell your wife and kids about the fact that when these bugs hatch there will be a few winged insect flying around the basement! If you forget to tell them you may be startled by some very loud screams emanating from within that area.

The bugs
A 1/4 inch square grid is used in some of the pictures. More pictures will follow as the season progresses. Temperatures are listed in Fahrenheit.

Black stonefly adult
Body length .28"

Brown stonefly

Brown stonefly adult and shuck
Body length .40"
Hatched at 58 (optimum 55)

Black quill nymph

Black quill nymph underside

Black quill adult
Hatched at 58 (optimum 55)


Black quill emerging


Rock cased caddis
Overall length .28"

Stick cased caddis

Olive/cinnamon caddis adult
(Elk hair caddis)
Body length .33" Hatched at 60

Spotted sedge (Elk hair caddis)
Body length .36"

Green rock worm caddis

Small cased caddis
Overall length .20"

Tiny black caddis in case
Overall length .30"

Tiny black caddis
Body length .20"

Black caddis
Body length .40"

Golden stonefly

Golden stonefly adult
Body length .75" Hatched at 60

Overall length .60"

Golden stonefly
Body length .50"

Golden stonefly after moult
The old skin is just visible to the bottom right

Golden stonefly
June 07, 12 hours later
Body length .70"

Golden stonefly
1.50" from head to end of wing

Golden stonefly top view

Golden stonefly empty shucks


Dragonfly adult and shuck
Hatched at 60

Yellow Midge
Hatched at 70 Body length .12"

Body length 1.5"

Damselfly and shuck
Hatched at 62 Body length 1.25"

Light Cahill spinner and old skin

Light Cahill or Grey Fox mayfly
Body length .27"

Light Cahill or Grey Fox adult
Body length .40" Hatched at 62

Light Cahill underside

Light Cahill nymph after moult

Blue winged olive

Blue winged olive
Body length .20" Hatched at 70

Hendrickson mayfly

March brown mayfly

Pale evening/sulphur dun
Body length .28" Hatched at 64




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