The rain-sun cycle causes mosquito hatches to come very frequently, this happens frequently when it rains. Once the eggs hatch it takes a day or two for all the mosquitos to land and die. Please be patient, your product is still working, a re-spray will not help. ONCE THEY LAND THEY WILL DIE!
Feel free to check for product effectiveness by shaking a bush to see if any bugs fly out, no bugs means the product is still working.