Resistance to pyrethroid insecticides amongst mosquito species is increasing worldwide at a dramatic rate. This has implications for serious mosquito borne diseases such as dengue, malaria and filariasis. Although not fully understood, the mechanisms of resistance are largely thought to be a result of selection pressures on caused by insecticides used for vector control. It has also been speculated, however, that changes in environmental factors may play an important role in the development of resistance to pyrethroid insecticides, and some of that data is evaluated in this article by Nkya et al, published in Insect Biochemistry and Molecular Biology. Abstract can be found here