Are the cockchafer beetles back?

A late winter/ early spring highlight of lake fishing in the central Victorian highlands, can be cockchafer beetle falls. Cockchafers spend most of their lives as grubs feeding on pasture roots; they’re those little pale grubs you sometimes find when you’re digging up the lawn. During the La Nina years 2010-13, the saturated winter soils really seemed to knock the cockchafers around – I’m guessing most of the grubs drowned. However the last two winters haven’t been too wet, and it may be that the population is rebuilding. On Saturday night at Millbrook I saw a few fly overhead and the same evening, forum regular Trevor saw some at Newlyn Reservoir and it sounds like the trout were on them.

What all the fuss is about!

What all the fuss is about!

IF the cockchafers are back, we’re in for some of the best early season dry fly fishing you can have. Here’s what you need to know:

  • Cockchafer beetles emerge from the ground, so although they may appear to be flying out of trees at times, you don’t need trees nearby to have great fishing: treeless paddocks are fine.
  • They can emerge and fly from late afternoon, but usually they don’t appear until after sunset and sometimes, not until right on dark. Don’t leave too early!
  • You’ll hear them as much as see them – cockchafers make a buzzing sound like a bumblebee and during a really big emergence, the noise can be deafening.
  • Basically the beetles seem unable to distinguish lakes from land and crash on the water after flying a hundred metres or so. You want no wind, or a very light offshore breeze, or in the case of a narrow bay or arm, a light onshore breeze will work. Too much offshore wind, and the beetles (and trout) will be pushed out of reach.
  • Frustratingly, it can take the trout a few nights to work out what the cockchafers are – I’ve watched them literally push a beetle out of the way to eat a tiny midge. Maybe after a long winter, a big chunk of floating protein seems too good to be true! However, once the trout work out what’s going on, they target the beetles enthusiastically. Then, you only need a few naturals to bring the trout up and after a couple of weeks of cockchafer action, you can even catch trout ‘blind’ on foam beetles when there are few if any real ones left.
  • By that stage, an oversupply is worse than an undersupply – the beetles are big food and if there are too many on a given evening, the trout become maddeningly erratic and difficult to track. Before long they fill up and stop feeding altogether.
What a trout sees.

What a trout sees.

Tactically, you need a fingernail to thumbnail sized fly (the naturals vary somewhat) that floats like a boat, leaving a decent imprint in the surface film. Foam or clipped deer hair beetle patterns are ideal. Colour isn’t all that important but black or dark brown matches the naturals. Because of the colour and low floating nature of the best flies, you may need a hi-vis tag on the fly itself or a nice visible indicator nearby to keep track of your offering in poor light.

A selection of flies that work. I don't find exact pattern is all that important, but effective flies must float like a real beetle - heavily hackled flies float too high.

A selection of flies that work. I don’t find exact pattern is all that important, but effective flies must float like a real beetle – heavily hackled flies float too high.

As with most rising lake trout, you need to go after an individual fish aggressively, rather than just throwing your fly among the rises and hoping for the best. The more real beetles, the quicker and more precise your presentations need to be (see Sight Fishing Mainland Style in the upcoming (spring) issue of FlyStream magazine). Give a two second pause when a trout takes – the rises are usually slow and deliberate.

A blast from the past - a nice rainbow taken on a cockchafer pattern, September 2009. Let's hope the beetles are back in earnest now!

A blast from the past – a nice rainbow taken on a cockchafer pattern, September 2009. Let’s hope the beetles are back again!

Finally, if you fish further afield, still keep an eye out for cockchafers from now until mid-spring, and anywhere there are lakes surrounded by improved pasture. In the Vic central highlands, the latest I’ve seen them is early October and they usually cease by mid-September. However I imagine at some higher and colder locations, they’ll start later and last longer. And by the way, fine mild evenings are good but you don’t have to rely on them. Once the beetles are really going, you can have great fishing on quite miserable evenings.