Tobacco is good for wasp stings. Just wet it and find a way to keep it on the spot on which you were stung. It takes the stinging away and some of the swelling. Or, cut a piece off a fresh onion and hold it to the spot of the sting. Works with bee stings as well.
Brewers' Yeast tablets contain a chemical (the Vitamin B?) which comes out in your sweat and helps repel mosquitos.
Honey is very effective in cough appearing during night. Lick slowly a tea spoon full mixed with a pinch of Termaric powder and for some time water should not be taken.
Plantain leaf, which comes from a common lawn weed, can be of help in removing poisons. This plant has oval shaped leaves with veins running the length of the leaf. It has spiked flowers. To use, simply chew the leaf and use the resulting mush as a poultice for bee stings, spider bites and even snake bites. You may want to put a bandage over the poultice to hold it in place. Change it twice daily or more often as needed.
If you are in an area and climate where you may be bitten by a snake, take the homeopathic remedy Lachesis with you. It may save your life!
Ordinary Vinegar (used in the kitchen) is an easy and effective remedy against insect stings, bites etc.