Someone once observed that civilization is about 5 meals from disintegrating. I think that if a serious shtf happens, you might a only a few days to a few weeks from dealing with bugs. When shtf, the mosquito control district, the regular garbage pickup, and the street cleaners might not be operating. The seasonal infestation of no-see-ims at the range on Saturday will be with you 24/7. To this end, I picked up some mosquito head nettings (and put one in the car), spray can insecticides, and several large containers of insecticide. I also made sure that I carry a couple of cans of insecticide in the car. There are also some containers of weed chemicals. Other approaches include putting dust upon yourself and standing around a smokey fire to hide your scent.