Perhaps Mexico has a different variety of mosquito than we have. We do have a problem with West Nile Fever though, and several viral encephalitis diseases. Heartworm in animals, particularly dogs, is transmitted through mosquitoes. Dengue fever does occur some in extreme southwestern states and Florida, but I think that disease is fairly uncommon in the rest of the US. I have no clue what specific strain of mosquito carries what disease though. I just know there are a couple of thousand varieties of them.
I have never heard any "expert" mention mulch as a problem when talking about mosquito larva hatching out. They always just say to empty anything that would result in standing water or treat the water to kill the larva. I guess standing water could represent a tsp. of water, but I don't think those warnings pertain to that small amount of water. I could be wrong though.
