Yarrow leaves are great after the fact for all kinds of bites and stings. The latin name is achillea millefolium, or something like that. I used it a lot mtb in Colorado. In the US it's common in subalpine areas and as a landscaping plant. You pluck a leaf, chew it up into a poultice and apply the poultice to a bite/sting. It's not exactly yummy, but it works great. It's more effective the sooner after the bite you can apply it. I realize this may not be the most pertinent advice for a tour of another country, but perhaps you could plant some around your home for use there. Or learn to identify it - you might be surprised to find it in the wild. I once was hiking with my gazelle-legged husband. Of course, I was behind him, so he would stir up the bees' nests, and I would get to walk through the angry cloud of buzzers. I got stung twice. Once I was away from the little buggers, I found some yarrow, applied it, and kept on hiking. I managed to keep the poultices on for 6 hours (putting a bandage over them helps). I didn't even have a welt, let alone any itching.