I'm B type too & always hunt by mosquito among others.
I once read an article said that mosquito love to hunt "acid-body" than "alkaline body"
How to become more "alkaline" pula dunno loh.... Lesser eat meat gua I think.....

P/S: If you feel itchy after kena bite, use alkaline-base shampoo to wash the itchy area. This will help neutralize the acid thingy so won't feel itchy loh ^o^