He received a patent covering several approaches that rely on the same principal: killing the mosquito eggs rather than the mosquitoes themselves.

Mosquitoes are considered a main carrier of the virus and stagnant water is a prime hatching spot for mosquito eggs.

Update 5 June: Congratulations to everyone who got it right: mosquito eggs.

As the mosquito eggs go through the filter, they are crushed.

Andrew's ponds were thick with water hyacinths and the special fish that eat mosquito eggs.

Anything that holds water for the few days needed to incubate mosquito eggs is doing so.

Efforts have also been under way since the start of spring to kill mosquito eggs.

The virus is maintained over the winter by transovarial transmission in mosquito eggs.

He said mosquito eggs "are well adapted to survive the worst winters.

Dead bugs and mosquito eggs were something else.