True Flies

I’ll bet that when the non fly fishing public thinks of ‘flies’ in association with fly fishing they don’t imagine mayflies, stoneflies and caddis. They think of ‘Louie the fly’ types—big fat blowies and various annoying little Muscas that hang around garbage cans and will apparently kill your kids and end civilisation if we don’t exterminate them first. On the other hand I suspect most fly fishers rarely give everyday houseflies and blowflies much of a second thought either. But these diptera, or common flies, are a diverse order of insects and should not be ignored.

The second fly fishing book I ever bought was Vincent Marinaro’s classic In the Ring of the Rise, with its evocative photos of feeding trout in Pennsylvania’s once-famous Letort Spring Creek. The chapter ‘A Game of Nods’ has always stayed with me. The fish in this particular story lived in a small back-eddy where food was accumulated by the swirl of the currents. It had all the time in the world to investigate insects caught in the eddy, and was very particular about what it ate.

As this spot was right beside where Marinaro rigged his tackle at the start of the day, he got to observe the fish at leisure. Initially he’d dismissed catching it as a not particularly significant challenge, but after he was frustrated by repeated refusals, the task became far more serious.

He took some time to observe what this fish might be feeding on and he tied appropriate flies. The ‘game of nods’ refers to the various levels of interest each succeeding fly drew from this fish, and the barometer of interest was the intensity of the fish’s inspection. The longer and closer it looked at the fly the nearer he knew he was to having the right pattern.

I won’t spoil the story by telling the ending, but what makes it even more engaging is that the insect in question was not some fine, elegant and rare mayfly, but the common old maggot-laying Musca domestica or housefly. He tracked their original source and found they were washed into the water from the dung-heap of an upstream dairy.

As a protest against the slightly disingenuous New Zealand tourism campaign that runs on the slogan ‘New Zealand—100% pure’, Carl McNeil of Once in a Blue Moon fame has registered ‘New Zealand—100% Poo’. The effluent from the dairy farms that have sprung up is adversely affecting the quality of many pastoral waterways, especially in Southland. But even the darkest clouds can have a subtle silver lining, especially if you’re prepared to look hard enough. All that poo means billions of summertime blowies. Many end up on the water, to the point where South Island fish now seem to expect them.

The diptera are the true flies and there are a lot of them: the defining difference between them and other winged insects is that they have only two wings. They range from fruit flies to those wicked horseflies that scrape away your flesh so they can lap up some blood. The next time you are up on the Thredbo River in midsummer—or anywhere in the high country for that matter—and the horseflies drive you nuts, just consider them as another hatch and dig out something appropriate from your fly box (as Peter Leuver suggested in FL#60), because fish do eat them. Then there are the big fat blowies, both bluebottles and greenbottles, the ones that hang around road kill and fresh dung, and are so prevalent in New Zealand. You may not think of (true) flies ending up on the water in sufficient numbers to seriously interest trout, but it seems they do.

OLD STANDBYS

They can be basically suggested by any fat-bodied fly pattern that offers a plump silhouette. The fuzziness and sparkle of a plump peacock herl body has a certain general fuzzy fatness and a very distinct blowfly body shape. Certainly generalist patterns such as the Red Tag, Black and Peacock and Coch-y-bonddu are deadly through the summer months on both sides of the Tasman and I think they have that ‘X’ factor, meaning that they simply represent ‘something edible’—and I imagine a lot of the time this includes the diptera.

A size 16 or 18 Red Tag has been my standard willow grubber pattern for several decades now and is still my first choice for those times when the fish are chomping on the grubs. I stumbled across its effectiveness for this tough fishing quite accidentally on a very early trip to the South Island, before I even knew of the existence of willow grubs. It was like my own game of nods. When nothing else had worked on a fish that rose freely and very steadily in a midstream bubble line, I worked my way through a relatively meagre fly selection to one that I knew caught fish at home, the Red Tag. Now I wonder whether it was being eaten as a common old diptera of some sort.

Another fly that has become very effective for me is the old New Zealand pattern Love’s Lure (FL#30). In Norman Marsh’s essential book Trout Stream Insects of New Zealand this pattern is his only reference to the diptera. This fly is tied essentially with peacock herl, even the wings being made from the tips of the sword feathers. Marsh says ‘On hot sunny days, under low water conditions, popped on to the middle of some deep hole near cruising fish, it can and does tempt the larger trout.’ On a spring creek that flowed through pasture country where no other fly would interest any fish lying out it certainly worked for me under exactly those conditions. There were plenty of cattle about too.

PHOTOGRAPHIC EVIDENCE

Although such patterns have been effective for generations, last summer a few things made me think we should consider the imitation of the true flies more seriously, and use them more frequently.

While photographing some willow grub feeders I noticed a couple of things. The first, as I suspected, was that drag was the real killer on willow grub presentations. It was especially critical on those fish that were tucked into the slower water at the back of a line of willows. The second thing I noticed was how early a fish at station detected a grub on the water. The third was that they did in fact completely ignore other insects you would not expect them to turn down. I even saw a fish spook from a naturally drifting mayfly. The exception was blowflies, or what looked like common flies. These were always eaten.

The evidence actually came later when reviewing the day’s images.

To photograph the full sequence of the take, you had to watch the body language of the fish. You always knew when something edible was on its way and I was astonished by how early they detected it. They’d slightly accelerate forward and begin to tilt their bodies as they planed towards the surface. This signalled the moment to squeeze the shutter. In some images duns and other insects could be clearly seen on the surface, but these were never taken. Only willow grubs and common flies seemed to be eaten, and once a small green caterpillar.

NEW-AGE HUMPIES

The green and blue metallic Humpies seem to have replaced peacock-herl bodied flies for a lot of stream and river fishing, though I suspect the visibility of the white wings has much to do with it. The bluebottle Humpy is a very well documented general pattern for any South Island stream (it’s also a killer in the Snowies when the march flies are about).

Well-travelled and experienced Kiwi fly fisherman Dan Isbister (a dairy farmer) once told me to use the bluebottle version of the Humpy in dairy country, but the green metallic version in back country areas. I stuck to his advice for a while and it worked, but in the end decided that if they didn’t eat one then they’d probably eat the other. One memorable brownie on the Ahurriri reinforced this approach. After inspecting and refusing a bluebottle Humpy it drifted nose-to-hackle with a green version for what seemed like a lifetime before eating it. It took the fly facing downstream, and before that big white gob opened up there was plenty of time to mentally rehearse a well-delayed sideways strike.

Now I’ve begun to use these fat generalist patterns as my standard flies on most of the pastoral Southland rivers, especially in those places where dairy farms are prevalent. Last summer I went through several dozen size 16 Red Tags and bluebottle Humpies on those lowland rivers. Fish that were seemingly locked into eating willow grubs travelled feet sideways to eat them, or simply chomped them down in tight and tricky situations where other fine and delicate flies and proven effective willow grub patterns simply did not work. I can only put it down to a taste for and a familiarity with Muscas.

Again on the South Island last summer, I spent a day float boating on Diamond Lake just as the cicada hatch was beginning. You drive in through some grazing land at the eastern end that’s usually packed with sheep and cattle. When I pulled up near the water the tread of the tyres of the Prado was filled with fresh dung, and thousands of bluebottles swarmed around the vehicle. Just a few days earlier, over a quiet beer at the end of a long hot day, I picked my way through the accumulated debris of road-kill insects caught on the front of the vehicle (as any fly fisher would do—is it any wonder people think we’re a bit wacky?) and noted the large amount of bluebottle remains, so these things were on my mind.

The southern shore of this gem of a lake is a strip of beech forest and I set out for that edge. Down at water level you get to see a lot of things you would usually miss. Damselflies skimmed the surface in millions and fish leapt to take them in mid-air. There were plenty of cicadas hitting the surface, and tight in against the shore among the overhanging trees the fish cruised quickly and took the naturals and their imitations at pace. It was a blistering hot windless blue topper of a day and by mid-afternoon, even though the cicadas continued to hit the water, all surface activity had ceased.

By then I’d reached the western end of the beech forest where it met pasture, and I pulled in under the shade of a tree for a rest (and to feed the local sandflies). Sixty metres away a mob of cattle came down to the water to drink. I lay back in the cool shade and took in the spectacular scenery of the Southern Alps.

A fish rose out off the drop-off, puncturing the sheen of glass with its snout. Then another: it was time to fish again. As I rowed towards the rises I noted that the surface of the water was speckled with black dots. They were those same big fat blowflies that had earlier swarmed around the car. I had no doubt the presence of the cattle had something to do with this. Two refusals on the cicada pattern prompted a quick change. A bluebottle Humpy landed delicately in front of a steadily feeding fish and was immediately clipped off the top. This is not a fly you would normally reach for to fish a glass-calm crystal clear lake. It’s usually associated with flowing water and brief inspection times.

Perhaps there’s a certain snobbery attached to fishing with imitations of such a ‘trashy’ insect. Or perhaps many fly fishers have simply overlooked their existence as a readily available food source. Certainly experience now tells me to never ignore them as a fly pattern, especially in pastoral areas, and I’m on a mission to build up the range of true blowfly patterns I carry. The new generation of blowie imitations, from innovative tiers such as Stu Tripney and Muz Wilson deserve considerably more fishing time, as do blowies generally.

STU TRIPNEY ON BLOWFLIES

Blowfly patterns are essential to have in your fly box. When I’m guiding I use a lot of different blowfly patterns, chosen to match the naturals in size and colour. Blowies usually start in late November and you’ll find them on the water right through until late March. Even if the trout are not targeting them on the day, a good blowfly silhouette will get them looking and moving up in the water—if they don’t eat the blowie they’ll take a nymph suspended underneath it. A blowfly with a small nymph is a great ‘go to’ rig for searching NZ waters—they make excellent indicators, with a strong silhouette. Lots of blowflies end up gradually sinking, so it’s always good to have the likes of my Klinkhamer-style Hi-Viz Blue Sparkle Blowfly, with its little black spindly legs hanging down to represent the half-drowned blowfly.

Stu Tripney is a Southland based guide, owner of Stu’s Fly Shop in Athol, and maker of the classic DVD A Foam Odyssey.