Oops I meant plants, not mosquitos (?!)
One problem with finding observed speciations, or any changes is that even if one new mammal species was expected to appear every 10 years that would mean 500,000 mammal species in the last five million years. Yet there are only about 4,500 mammal species on Earth today.
So it seems more likely that we should not expect to see dramatic changes in mammals in observable times even if evolution is true.