[Terry Coging]

Fished Carsington Reservoir yesterday. First few casts we raised and lost a couple to the dry fly. A very promising start, so we continued with the dries but nothing. My boat partner changed to lures and caught a couple so I did the same. My first fish a superb 2 3/4lb rainbow was hooked in the tongue and bleeding so it had to be despatched.  We were asking ourselves why were the fish taking dries early on and then they just stopped? When cleaning the fish the answer was there in it's stomach, which was almost exploding with Cockchafer's!  There must have been a huge fall of Cockchafer's during the night and the fish had a feast. Early morning maybe saw a few fish mopping up the stragglers and then retiring for the day.
With hindsight I should have spooned that fish.  What represent a Cockchafer?

[Derek Roxborough]

were these Cockchafers or great diving beetles? chafers are around much earlier in the year May /June time, hence the name June bug,but a healthy lake can have a big population of water beetles,  Derek Roxborough

[Terry Coging]

Definately Cockchafers Derek.  I have been observing Great and lesser (corixa) diving beetle for decades in my ponds.  I doubt if the Cockchafer beetle is a prolific in the Highlands due to it's food source which is root crops for the larva such as potatoes.
The drought this summer has played havoc with our terrestrials.  Saw the first daddy of the year this week end! The larva of the Cockshafer can burrow as deep as one metre, so a lot will have been trapped in the earth until the rain came along.

[James Laraway]

that is one insect that i will not be looking up on the internet...

[Sandy Nelson]

 

Terry, pretty sure the cochybundhu is a cockchafer beetle imitation, if not it is very similar
 

Sandy

[Terry Coging]

That's what I was thinking Sandy.  Many years ago there was a big fall of beetles on a lake I fished in France. The fish were going mad. Tied up some beetles to resemble them and went back the week after. Nothing. Still got a couple in my box which I try from time to time but no deal.  Over a twelve year period on that lake I have not seen anything like it since.  Those beetles were about the same size as a cockchafer but rounder and a coppery colour.  So unpredictable.

[Derek Roxborough]

Just seemed late for CC's, is cochybundu not Red and Black in welsh?  Derek Roxborough

[Terry Coging]

My apologies for getting this completely wrong.  Further investigation showed that the beetles were Red legged Shield Bugs  .

Derek - I bow to your better entomological knowledge     Don't see beetles very often. Pity really.

ps - thank you for your diplomacy Sandy.