Panama jungles are full of sand flies - their painful bites made me long for the sweet release of a machete hit

I took lots of Deet with me – the insect repellant that burns plastic but is supposed to be OK to put on your skin is surely some sick local joke

In the various sorts of sand fly only the female is responsible for biting and sucking blood, as she requires the protein to make her eggs

I would not recommend the jungles of Panama for a holiday. In fact, I would not recommend them for anything except, perhaps a honeymoon for Ray Mears. I am still recovering from the effects of the invisible enemy – the sand fly.

I’d love to be able to tell you what this hellish beast looks like but I have no idea. For all I know it could live in my imagination, save for the fact that my entire body is covered in incredibly itchy and painful bites.

There is a Maori story about sand flies – it claims God had just finished creating the fjord landscapes around Milford Sound, New Zealand. It was so stunning that it stopped people from working. They just stood around gazing at the beauty instead. God became so angry at these unproductive people that she created the sand fly to bite them and get them moving. I can tell you that this does not work. Once the sand flies have done their business, it is very difficult to get anything done except grumble and scratch.

I took lots of Deet with me – the insect repellant that burns plastic but is supposed to be OK to put on your skin is surely some sick local joke. The more I put on, the more sand flies swarmed around me in invisible attack squadrons. I think the locals know that sand flies love Deet and promote its use among visitors so we become mobile fly traps leaving the Panamanians to go about their business of siestas and cigar-smoking untroubled.

I was exploring a relatively unvisited area and bought a handsome machete before my departure into the backwoods. I must admit to having very little machete experience save for a couple of days in deepest, darkest Congo when I was hunting the Mokele-mbembe (blocker of rivers), a monster that is supposed to inhabit Lake Tele. Then I was attacked by a porter (driven mad, no doubt by sand flies) with a machete but escaped unscathed. For the record, I asked in several supermarkets whether they stocked Um Bongo. It turns out the ad was a lie. They do not “drink it in the Congo”. But I digress.

A machete is an exciting thing to wear on your belt. It makes you feel like an explorer, a “real” man. This lasts until you try to use it, and realise it is an incredibly potent self-mutilation instrument. In your mind you hack through vines and bushes with a simple swipe of a muscly arm. The reality is that you take about 20 sweaty and exhausting goes to cut anything. You become so tired that you get careless and can’t stop the machete swing when it does eventually sever something. Suddenly you have a foot-long piece of sharp steel rocketing towards your body. If you cut the inside of either thigh, you risk severing a large artery that would make you bleed out within half an hour. I suffered innumerable near misses until exertion and madness began to make me long for the sweet release of a machete hit.

I am home from the heart of darkness and Cotswold drizzle never felt so good.