Regarding chiggers....if they have already established their hold on you, simply mix up some sulphur and vasoline into a nice paste and put it on the little red round spots. The mixture seems to suffocate them in their home. At least the itching stops. You can get the sulphur at the pharmacy. Sometimes they have to order it from a supplier.
You can also put this mixture on before going out. Dab some where your clothes may be a little tight. Chiggers like tight spots. Good Luck.