Airplane buzzing the bay - update

We tried using dragonflies here and it was effective but as soon as the city fogged with malathion, it killed all the dragonflies. But at the same time malathion was way more effective, getting fast results and cheaper on the long run and money talks. But now malthion is banned as of 2016 here so they are looking at other products. Several natural methods do work but just aren't as effective as chemical spraying. What you mentioned as preventive methods are important as well but the reality is you can't target all at risk areas if you don't have the manpower and budgets. And with the diseases now being carried by moskitoes, chemicals need to be used, even with the bad side effects.