Brazil and other countries have stepped up efforts to control mosquito populations, including public information campaigns, wide-scale spraying of insecticides and attempts to eradicate the pools of standing water where the mosquitos breed. The Centers for Disease Control recently confirmed the widely-suspected link between the mosquito-borne Zika virus and microcephaly, a condition which stunts brain development in infants. This ensures that benign insects aren't drawn into the trap along with the mosquitos. The unique combination of scents and lighting targets mosquitos specifically, says Otto Frossard, planning director of Posterscope Brazil, speaking to Campaign. The creators say the billboards can attract mosquitos from over two miles away, and catch hundreds each a day. The mosquitos buzz around aimlessly until they die of dehydration, after which they fall to the bottom of the enclosed billboard as proof of its efficacy.
Small entrances near the "sweat glands" allow mosquitos to enter, where a series of fans creates a pressure difference with the outside, trapping them inside. Fluorescent lights on the display further enhance the billboard's allure. The billboard draws mosquitos in by pumping out a combination of lactic acid and carbon dioxide, which mimics the aroma of human sweat - a proboscis-watering scent for mosquitos. The agencies encourage others to create their own mosquito traps, which need not necessarily double as advertisements - it costs about $2,800 to construct one. Blueprints and instructions for constructing the billboards are open-source and can be found here. There are currently two billboards installed in Rio de Janiero, with plans for another in the coming months. A result of a partnership between NBS and Posterscope, the installment reads "This billboard kills hundreds of Zika mosquitos every day," and the dead insects littering the bottom of the case prove they made good on that promise. A billboard created by two ad agencies in Brazil doubles as a deadly trap for the Aedes aegypti mosquitos that spread the Zika virus.