Tackle and tactics: summer insects for trout fishing

Summer is a time to fly fish for trout with terrestrial patterns, i.e., imitations of land insects that stray into trout rivers or get blown by summer winds. Terrestrial insects provide trout with a couple of opportunities for veritable feasts. Cicadas start to emerge after New Year and trout are quick to seize the opportunity to grab the mega-sized meal of any cicadas that bumble into the water.

Last summer I went fishing in a wilderness river. Just being there was a delight. Although it is truly wilderness with its plunging, exuberant river, beech forest, and the rearing outline of the mountains, the access is ridiculously easy by a farm road.

I drove up the valley, stopped at a bend, assembled gear, and walked towards the river to cross it.  I like to fish the side that most anglers, by habit, don’t fish. On the way up, the buzz of the cicadas was loud through the beech forest. It was a strong hint to try a cicada pattern.

So I started with a cicada and a dropper of a stonefly nymph. What an abomination to cast – for me anyhow. A brownie sidled up under the cicada, and I missed the take completely. To hell with a dropper! Off it came and I fished just a cicada. Five metres upstream I spotted a good fish, again in front of a submerged boulder. The fish came up to the cicada, I paused the vital few seconds to let the trout turn down, and I was hooked into a feisty brown that came up out of the water, once, twice then dashed across the river and the fly came away.

Disappointed, I reeled in and as I did, noticed the fish come back towards me and then upstream, to resume its original lie. And the fish was finning, obviously returning to its feeding mood.

Well, the cicada failed to get a second response and who could blame an upper Wairau fish that can be so damned spooky after having flies tossed at them seven days a week by other anglers and mostly a procession of guides and clients?

A bit further upstream, I saw a fish slant up to the surface and then it had gone down into the swirling bubbles. The cicada drew a response from it and I landed the speckled brown trout. I released it carefully.

The cicada is a much-neglected pattern, yet trout go dotty over it in midsummer. I should heed lessons more because I remember many years ago on the Wairau downstream near the Branch River confluence, finding a fish feeding like crazy. I cast and cast and cast, nymph after nymph after nymph to it until it finally took a big Hare and Copper nymph size 8. In the stomach were over a dozen big fat, juicy cicadas. The big Hare and Copper had passed for a drowned cicada.

As I gutted it, I realised the cicadas were chirping away. I had failed to listen for the clue.

Cicadas are a must in the fly box. Look what Norman Marsh wrote in his classic book Trout Stream Insects in New Zealand: “May the backcountry angler tread in peril of fishless days who does not include in his repertoire of trout flies one that at least looks something like a cicada.”

Drowned cicadas are always likely to be in the current, particularly if there’s a wind to blow the insects in. Windfalls of big tucker-like cicadas are relished by trout.

The other windfall for trout in mid-summer is the willow grub. In the warmth of summer, willow leaves overhanging most rivers get a blighted appearance with small red blisters appearing. Those blisters are the home of a small light greenish-yellowish coloured maggot-like grub – the larva of the willow gall sawfly.

Willow grubs often drop into the river because so many willows thrive along river banks, overhanging the water. The late Norman Marsh was under no illusions when he wrote in his fine book Norman Marsh’s Flybox that “once trout lock onto willow grubs, they become very selective and it is the devil’s own job to catch them.”

Norman Marsh’s dressing in Trout Stream Insects of New Zealand involves brown-tying thread, at least a size 16 – but preferably 18 –  light gauge hook, a primrose silk body, and a head of brown thread. Since the grub has a small dark head, a turn of peacock herl may be worth incorporating, while I personally favour a brief (half a turn?) of small hackle – perhaps blue dun.

Similarly, fishing under willows requires a short flick or roll cast. It is certainly challenging but isn’t that what trout fishing is all about?