This is one of the coolest things I have ever heard of. Genetically engineering mosquitoes to fight Dengue fever.
Here's how it works. Scientists genetically engineered male mosquitoes with a genetic flaw that kills their offspring in the pupa stage. So they release the male mosquitoes, they mate with wild females who lay the eggs, and all the offspring die. The cool thing about killing at the pupa stage is that the hatched eggs still go through the larvae stage and compete for food with the wild larvae thus preventing even more mosquitoes.
I know what you are wondering. How do they grow the mature mosquitoes with the genetic flaw? They added a gene that knocks out the genetic flaw if the larvae are raised in water containing tetracycline. That is just fucking cool.
The article I read states that there are many advantages to this approach:
"This system has several attractive features. First, since it is only males who carry these genes, no one will be bitten by genetically engineered mosquitoes. Second, because the gene construct is lethal, it shouldn’t spread into the wild mosquito population — instead, it should eliminate it. Third, the fact that the gene is lethal at the pupal stage means that fewer engineered mosquitoes need to be released. Finally, in a traditional control program, the hardest part is finding the last of the animals you seek to eradicate; in programs of this kind, the males will do it for you. Males, after all, have evolved to be good at detecting females."
Here is the whole thing: