Este estudo recebeu recursos do Programa Conjunto Brasil-Suiça de Pesquisa (Bolsa nº BJRP 0112-08), do Guggenheim-Schnurr Stiftung (Basiléia, Suíça) e do Conselho Nacional de Pesquisa (CNPq 590,154 / 2011-7, CNPq 472,491 / 2012 -1).Aedes aegypti and Ae. albopictus are two highly invasive mosquito species, both vectors of several viruses, including dengue, chikungunya and Zika. While Ae. aegypti is the primary vector in the tropics and sub-tropics, Ae. albopictus is increasingly under the public health watch as it has been implicated in arbovirus-transmission in more temperate regions, including continental Europe. Vector control using insecticides is the pillar of most control programmes; hence development of insecticide resistance is of great concern. As part of a Brazilian-Swiss Joint Research Programme we set out to assess whether there are any signs of existing or incipient insecticide resistance primarily against the larvicide Bacillus thuringiensis svar. israelensis (Bti), but also against currently applied and potentially alternative insecticides in our areas, Recife (Brazil) and the Swiss-Italian border region.