Too many game anglers dismiss the study of insects as being too complicated and not that important when fly fishing. This is simply not true.
Six Stillwater giants
The following are some of the most important groups of insects and crustaceans for trout. Midges Because of their sheer numbers, midges are one of the most important insect groups for Stillwater trout. Like most other insects, a midge has four stages of growth: egg, larva, pupa and adult. The colours of the immature insects range from black to olive, brown, orange, green and red. The fly fisherman is concerned mainly with only two stages of this insect – the larva and the pupa, both of which can move around. An adult imitation is only important when mated females return to lay their eggs on the surface of the water.
Midge larvae, known as bloodworms, can grow up to 19mm long. They live in the silt at the bottom of lakes. To fish a bloodworm imitation, slowly retrieve it directly along the bottom.
Midge pupae or ‘buzzers’ grow by moulting their outer skin. In the pupal stage they can be found at all depths of water.
In still conditions when dust and other particles — combined with the surface tension of the water – make it difficult for the hatching pupae to break through, trout go on a feeding spree, and midges are picked off by the thousand.
Most major hatches occur in spring and summer, during the early morning and evening. These are prime times to fish a midge pupa imitation. Fish an artificial emerger – this has a polystyrene ball located near the eye of the hook – in the surface film, giving it an occasional twitch to imitate a struggling pupa in the process of hatching. Darting damselflies Damselfiy nymphs make up a large proportion of a trout’s diet in summer. They are usually brown or green, blending in perfectly with their weedy or reedy environment. Damselfly nymphs are capable of short bursts of speed.
The nymph stage lasts about a year -though some species take up to five years to develop into an adult.
Fish a damselfly imitation in weed beds along the bottom or just under the surface in shallow lake margins. Experiment with different retrieves such as slow and steady along the bottom or short, fast strips near the surface.
Margin-loving corixas These brown beetle-like insects – known as lesser water boatmen — are found on most stillwaters near shallow weedy margins. They thrive on algae and other plant debris. Varying in length from 4mm to about 10mm, they have a remarkable ability to live in water with a low oxygen content. You can often see them rising to the surface and then quickly sinking to the bottom like a small stone. Corixas carry their air supply in a bubble between their wings and back. When the air is used up, they must leave the security of their weed or root and make a dangerous journey to collect more.
Fish the fly in shallow, weedy areas, suggesting the insect’s natural habit of sinking from the surface to the bottom. Caddis flies Some species of caddis larvae make shelters from sand, small stones and plant debris. Others rely solely upon camouflage. During the larval and pupal stages the insects develop under water.
Even though the pupa is fast-swimming, it is no match for a trout. At the point when the insect is about to break its sheath and hatch into an adult on the surface of the water, it is virtually immobile for a few seconds and vulnerable to hungry fish. lb imitate the caddis larva, fish a pattern such as a Stickfly slowly along the bottom. To imitate the quick and ever-popular pupa, fish an imitation such as Goddard’s Sedge Pupa near the surface of the water – particularly at dusk when major hatches of caddis flies take place. Remember, the pupa can swim quite fast, so you should retrieve quite quickly.
Fish an adult sedge imitation static on the surface, giving it an occasional twitch to suggest life. Crustacean magic Water fleas, freshwater shrimps and hoglice are an important year-round food source for trout. Recently hatched trout often feed on daphnia until they are large enough to tackle bigger mouthfuls. Since daphnia are so small, proper imitation is difficult.
Stillwater trout may feed exclusively on shrimps and hoglice during the lean months in spring when insect life is low and competition between recently stocked fish and overwintered trout is high. Freshwater shrimps and hoglice are much more common around weeds where they have cover. In April and early May, fish an imitation slowly right along the bottom. Terrestrials Land insects such as hawthorn flies, daddy-long-legs, black gnats and flying ants can be blown on to stillwaters in late summer and early autumn when they are numerous. Terrestrials are in an alien environment as soon as they touch water. Many become trapped in the water’s surface and then waterlogged – an easy meal for trout. Use floating line and long leaders of at least 6 lb breaking strain.