Mayflies and other spring insects

With waters gradually warming up, fish start feeding again with avidity and for fly fishers, this heralds a double opportunity: to find optimum conditions to fish on the surface of the water but also to (re)discover the variety of insects present in the habitat at this season. But let us start with the one who carries the name of May. Impressive by its large size and majestic shape, it is without surprise that the mayfly is found by the water side.

More surprising for novices to entomology, ephemera danica and vulgata show a liking for trees where they find refuge after hatching and whilst awaiting their egg laying stage. Mayflies bewilder by their estonishing flying ability and it is not unusual to observe their presence several hundred meters from the stream that saw them take to the air. By examining bankside vegetation or simply by opening curious eyes out of habit, spotting them is a rather easy affair. With a little stealth, they even make themselves pretty for the camera, which is a godsend for realistic fly tyers! The one portrayed below had taken refuge in a tree by a footpath.

Rather than on top of leaves, it is advisable to look underneath them and armed with this piece of advise you will undoubtably succeed. The bulk of hatches takes place in May hence the name mayfly and throughout June too; sometimes depending on the location, a trickle of flies may occur all the way to September. As for the beautiful black specimen below, it is a shuck - in other words an empty body shell - that I fished out of the upper Thames river whilst it was drifting on the surface. The thorax slit through which the future upwinged insect escaped from its former body is clearly visible.

But enough with the mayfly! A month earlier in April, the hawthorn was born and making a name for itself with an in-flight display of its characteristic shape due to its dangling abdomen. Contrary to most other protagonists in this article, hawthorns are terrestrial insects. When hatches occur they tend to be massive and result in insects being randomly blown off onto water where they turn into convenient trout food. Dame Trout has indeed a reputation to be rather opportunistic in her feeding habits.

In May, nature demonstrates its generosity, perhaps just to apologize for the rigours of winter. This is the right time for damsel flies to make an elegant appearance.

Similarly to hawthorns, damsels hatch en masse triggering acrobatic displays amongst trout when the fish rise in demonstrative boils to grab the insect at it skims at speed the surface of the water. Damsel nymphs live sub-surface for several years. The transformation into an upwinged insect start with the nymph climbing a grass or reed stem before breaking free from its shuck.

The nymph then starts unfolding its delicately veined insect wings. A little time will be required for them to dry and rigidify under the combined effect of sunshine and an intense blood circulation. As soon as the damsel feels ready, she takes off to put some distance between itself and any potential terrestrial predator. Whilst in flight damsels make themselves conspicuous by their acrobatic flight, they do leave remarquable tracks on the vegetation too.

Come early June, lakes and ponds teem with damsels and trout gorge themselves on this gift from nature. These are times of abundance. Damsel flies are multi-facetted and never cease to estonish: an insect that is in the same time graceful, fragile and elusive. Some would say a balarina of the skies ... 

And each individual to show off its colour to its kins. Bankside vegetation can sometimes be littered with damsels and each step taken by intruders sees a cloud of insects escape at a high speed that the human high struggles to cope with. Delicate speeding arrows in their electric blue coat...

Amongst predators who can pretend to turn damsels into a snack, swallows and sand martins comes first. Mallards are known to be partial to them too and so is a close relative to damsels who shares its habitat and life cycle: rise the mighty the dragon fly.

Fly fishers in Europe seldom tie a dragon fly imitation on their leader probably because insect populations are varied and trout are spoilted for choice. In more remote places like Patagonia, a dragon fly is a dish fit for a king and can trigger an explosive take. Opportunism is key to survival for salmonids in a habitat where prey density varies dramatically. Occasionnally, an unexpected gift falls from the sky. It could be called Coch-y-Bonddu or caddis ... 

This quick whistle-stop tour would not be complete without a mention of sedges. There are dozens of species but one characteristic remains: no wise fly fisher should venture out to the water without a few sedge patterns in his flybox. Aside from the large olive family, sedges form an essential part of salmon trutta’s diet, a core item on the menu for the brown trout of our rivers.

Fly fishing holds so many challenges that for some, entomology might be one step too far. Those anglers will seldom be motivated enough to gather more insight than is really necessary. Far from blaming them, I actually share their burden as I find entomology all too frightening. Having said that, perhaps the more reluctant could start gently with the simple gesture of taking a camera when going out, whether the rod is allowed out or not. Hopefully this article shows that estonishing sights of insects await the curious fly fisher and that some valuable lessons may even be learnt.