Understandably the likes of buzzers and damsel nymphs grab the headlines in spring, but at some point in late spring, we can expect terrestrials of one kind or another to feature on the trout’s menu. And once the weather warms up, a full complement of terrestrial is on the cards, giving us untold opportunities in terms of dry fly fishing. ‘Terrestrial’ is a generic term we use to describe a whole host of bugs and creepy-crawlies that begin life on land and inadvertently end up tumbling to water. Many of them live below ground as larvae or pupae, only to emerge as winged adults on warmer days. As they’re not designed for water those that crash land at the surface pretty much become trapped, making them easy pickings for hungry trout. As we’re not relying on a hatch now, one of the beauties about terrestrials is we can expect a ‘fall’ of them at any time.

terrestrials on the water

Once the weather warms up, a full complement of terrestrial is on the cards


Beginners often agonise over fly life identification and given that hundreds of terrestrials are evident in the UK they have good reason. Yet, there’s no need to reel them off by name alone. Being observant is far more important when, if you see a wee black fly drifting by, regardless of its Latin name, you just pluck an appropriately-sized imitation from your box and present in the manner of how they are behaving. That said, those new to fly-fishing will already know a surprising number of species. These include, daddy longlegs (crane flies), moths, beetles, caterpillars, flying ants and greenfly. Just as common, but perhaps less well known by the general public will be black gnats, hawthorn flies, heather flies (all closely related), saw flies and weevils.


Many terrestrials are weak flyers, the ungainly daddy longlegs being a classic example. Granted, they might have wings, but even a moderate breeze can send them tumbling to water. It may sound like a contradiction, but extremely blustery conditions rarely see many terrestrials blow onto the surface! Over millennia, these flies have evolved to avoid breezy weather by hunkering down in the grass. Granted, some will venture that bit too far from cover, only to be whisked away to a watery death, but on the whole they remain safe. Conversely, those ‘soft’ days when zephyr-like breezes occur produce the best of terrestrial falls. Flying out on warm breezes to look for a mate, many flies tire quickly. Add to this that those that wander over water will often be immobilised by cool updrafts from the surface and suddenly it’s obvious why calmer periods are favoured by trout and anglers.

Calm water


Driven by the sun’s warmth, many terrestrials are rendered lethargic come early mornings. However, as the land heats up they become more active. It’s usually late morning before land flies stir properly. Being carried on soft breezes, many bugs inadvertently take a dunking along the sheltered shoreline first (see diagram 1). Usually, a band of calm water exists here too that holds any surface flies there for a considerable amount of time. This then should be our first port of call.

fish location


With trout topping, dry fly will inevitably be our initial approach. We can make casts directly downwind though – given our imitation is tethered to the leader, fly line and ultimately ourselves – there’s little scope for our fly to drift naturally now. At first this might not matter too much, as many trout initially pounce on terrestrials as soon as they touch down. However, this honeymoon period is often short-lived because fish quickly learn that terrestrials, which have become swamped are easier to intercept. To emulate this not only does our fly need to be low riding, but also has to conform with the wind direction. It’s best then to angle your casts to any breeze, which will afford a degree of natural movement to our flies.(diagram 2)

angle your casts


Generally speaking, we’re taught to present our dry flies with a level of finesse, so they alight on the water without fuss to hopefully avoid spooking nearby trout. However, some terrestrials (namely beetles and daddy longlegs) do have a habit of making a commotion or crash landing. This gives us licence to deliver certain imitations so they announce their arrival by gently splashing down at the surface. Trout feeding on large beetles (bracken clocks for example) fully expect to hear their prey land. This is easily achieved by stopping our rod a little lower on the forward cast to flip the fly over. (diagram 3)

Bracken clock one of the larger beetle species.


Sometimes, terrestrials can occur in overwhelming numbers to the point of carpeting the water. In such circumstances an appropriately-sized imitation can pale into insignificance when our fly merely becomes a needle in the haystack as far as trout are concerned. One way of making our fly stand out is by stepping up in size. For example, when copying hawthorn flies we might look to a size 12 hook. Instead, think of knotting on a larger imitation of say a size 10, or even a size 8 fly. This now stands out in the crowd, often attracting feeding trout to your fly.

head into the wind


Eventually, terrestrials littering the sheltered shore will drift down to the more exposed bank (see above). Not always, but usually I’ll head there later in the day when numbers of fly have accumulated close to the exposed shoreline. Admittedly, casting becomes more challenging now, but again, angling casts to the wind helps (diagram 4). Remember too, the fish are often patrolling close in, so casts needn’t be long.


Another trigger worth considering is movement. Admittedly, it’s often drilled into to us to present our dry flies static (I’m the worst culprit here!). However, occasionally twitching your fly can have the desired effect. This is best done when trout are perceived to be heading in the general direction of your fly. We can tell this by closely studying a rise form, or push of water left by a moving trout (diagram 5). Once we anticipate a fish to be in range, a gentle tug on the fly line will cause our static fly to shudder. Hopefully this disturbance will be enough to attract any trout. We must remember that many terrestrials often kick and fidget in a vain attempt to free themselves from the water’s surface, which creates quite a commotion.


Even a small cluster of trees on say an upland tarn can harbour many terrestrials, or fly life in general – surrounding foliage too, like tussock grass for example. So, it makes perfect sense to position yourself just off to one side or amongst any trees or shrubs, no matter how modest they may appear.


A cliché I know, but being observant when fishing pays handsomely. For example, where terrestrials are concerned, we should be constantly aware of our surroundings. A herd of cows munching grass in a meadow attract and disturb flies, many of which will be blown onto nearby water. The same can be said of a farmer ploughing his fields, or turning hay over. Again, countless flies are disrupted to be deposited on water. When such activities occur, make a point of getting round to the adjacent shoreline asap!


Having been tossed about in the waves, terrestrials on the downwind bank are often fully submerged. Here they hang inert an inch or two below the surface. While dry flies still have worth, a team of Spiders or wet flies can be deadly now. In the interests of avoiding tangles, a two-fly rather than three-fly rig should be considered (diagram 6). These should be pitched out and fished back using a steady figure-of-eight retrieve. Top patterns include Black Spider, Black & Peacock Spider, Black Pennell, Bibio and Zulu.



Wet fly tactics can be extremely effective when loch-style drifting in a boat. As we’re casting with the wind at our backs now, a team of three flies can be used. These should be positioned three feet apart on a 12-foot leader (diagram 7). As we’re usually exploring more exposed sheets of water with boats, chances are wave action will drown any terrestrials. Although wet flies are drawn back they might not be fishing quite as fast as we like to think due to the drifting motion of a boat! Again, dark-coloured flies should be our first choice (mentioned above).

from the boat


Once upon a time, dry fly enthusiasts turned to heavily-hackled dry flies when copying terrestrials. Granted, such bushy imitations tempted fish, but in many cases, trout would initially slash at these flies in an attempt to drown them. Of course, any disturbance seen by the angler was misinterpreted as a taking trout. Little wonder anglers were left feeling bamboozled after tightening and feeling no resistance from a fish that had supposedly engulfed their fly. As mentioned, terrestrials are not geared up for life afloat, so they quickly become swamped to assume a low-riding attitude in the surface film, almost poking through it at times. Designing our flies to do similar not only copies the natural to the letter, but being easier for trout to intercept usually results in a lot more positive hook-ups. Foam-based patterns and those with the hackles clipped away on the underside should be your initial choice.

foam bodied beetle

A foam-bodied Beetle will ride low in the surface film.


Make a point of checking spider’s webs in gateways, or along hedgerows as you stroll to the water. They often provide up-to-date clues on what terrestrials the trout might be feeding on.

For anymore advice on fly fishing, please feel free to contact the Angling Active team. We are more than happy to provide you with information on fly fishing tactics.

This article was brought to you in association with Trout Fisherman Magazine.