Caenis generally hatch in very large numbers on hot clammy evenings. The evidence is easily seen by the numbers on our coats or cars or any surface where they can sit in order to shed their dun skin to become a spinner. The transformation from nymph to dun and then to spinner is made sometimes in minutes so the trout can be feeding on nymph, dun and spinner, at the same time.
Caenis are members of the group of insects known as Ephemeroptera, or better known among anglers as olives or upwing flies.
The first stage in the Caenis life cycle is egg, which hatches into a nymph and it is this nymph that will crawl along the silt or mud on a slow section of the river or on the lake bed. For the purpose of this article I will concentrate on the lake dwellers from here on. At this stage they are of little interest to the fish or angler, but when they rise to emerge into the dun or sub imago it is then that the story gets interesting. The following picture shows a sample which was spooned from a fish taken during a Caenis rise.
The sample shows Caenis devoured in huge numbers at the nymph emerger stage. The next stage is the dun or sub imago stage which only lasts on some occasions for minutes. The dun settles on a surface, perhaps a car or some ones coat or perhaps the window of the fishery lodge.The final stage in the life cycle is the transformation to spinner or imago. When the spinner female goes back to the water, lays her eggs and dies, this is when we have the life story and it is now time to catch the trout on caenis imitations.
Catching the Trout
Over several years I have developed a method of fishing for trout during the Caenis hatch. During this time I came to realise that trout follow a pattern when eating Caenis. I personally do not target the nymph feeders because it is more due to luck that a hook up occurs and as a purist type I like to catch the trout on spinner and dun patterns.
Trout rise patterns are perhaps predictable in lots of cases by observing the rises for a short time before casting. When we do this we come to see the direction that the trout are travelling and the frequency of the rise. Some fish move in an oval pattern and some travel along or close to a bank while others seem to travel in a straight line across the lake, but usually they come around the same track again.
Now we know the direction of the rising trout next thing we need to examine is the sequence of the rise and dive pattern because it is crucial that when a trout arrives at our fly that the fish is coming up to take a fly, rather than going down after taking a fly. This is because otherwise the trout will pass under our fly without seeing it. If we look closely we will discover that there may be large concentrations of the insects on these areas of the lake and the trout will not deviate off its route in order to take a fly, so our fly must be on the trout’s nose when it rises. The hundreds of Caenis per square metre of water mean that the odds are against the likelihood of the fish selecting our fly and for this reason it is important for the cast to be made to the fish with pinpoint accuracy while judging the arrival of the fish to coincide with the rise.
Problems, Limitations & Presenting the Fly
Some problems occur when suddenly the fish changes course away from the route we assume it will take. This thwarts our current effort so we try again. Sometimes the fish do not rise in the sequence we expect, again our effort’s are thwarted but in spite of this if we persevere to target specific fish we have a good chance of success with at least one of our attempts.
I have watched with interest on many occasions when large red sedges have fluttered along the lake after emerging and a trout has risen for them. A very remarkable fact is that quite often the trout has had two or more efforts before it was successful in taking the fly, so it made me think about the times when trout rose to my Caenis without actually taking my fly. Was this refusal due to the trout seeing the deception? Or just a miss by the trout? I have tried to find an answer to this but the Caenis are too small to observe on the water to actually get any confirmation of this.
Next condition we have to fulfil is to present a fly which will fool the trout into thinking it is eating a Caenis. I do know some anglers who have their own views on Caenis fishing where they present the fish with some entirely different fly pattern and strip it past the trout and sure enough it does work occasionally - but perhaps it is more satisfying to catch or deceive the trout with an imitation of the Caenis.
Over the years I have come up with a pattern which I am not sure I can make any more appealing to the trout. I have developed a parachute pattern (after several changes and additions) and a spinner pattern and have had success ranging from moderate to super and even the occasional disaster on Caenis rises. At least I can have the pleasure to rise the fish to my imitation on the occasional time when I cannot hook them.
Tying the Caenis
Caenis Dun or Spinner
Thread: Creamy lemon Sheer 14/0
Post: Fluorescent white antron
Tails: 3 Badger cock neck cape fibres
Body: Tying thread
Thorax: Thread blackened with permanent marker
Hackle: White genetic cock neck
1. Thread 1/4 Hook Shank tie in point
2. Butts cut off and ties in securely
3. Post polled and ready to recieve hackle
4. Tails tied in and body finished
5. Blacken thread for Thorax
6. Thorax made with turns of Blackened thread
7. Hackle offered to hook
8. Hackle ready to wind anti-clockwise
9. Hacke tied in and whip finished
10. Eye Varnished
11. Post varnished to stop hackle rising
12. Finished Fly