Mosquito-borne illnesses such as dengue fever affect tens of millions of people each year, however, genetically altering the insects so that they produce flightless females could help slow the spread of these diseases. A team of researchers recently engineered such mosquitoes, altering the genes so that they disrupt development of the insects' wing muscle. Within six to nine months of their distribution, scientists say, the modified mosquitoes could suppress their native, disease-spreading counterparts. In time, the flightless mosquitoes may prove to be a viable alternative to chemical insecticides in the fight to suppress the dengue-carrying mosquito population.