Bees play a fundamental role in maintaining the balance of ecosystems. They are responsible for the pollination of 80% of flower plant species and their impact on agriculture is estimated at 174 billion dollars per year (Institut National de la Recherche Agronomique). However Apis mellifera, the most efficient and widespread honey producing species, is particularly affected by the mite Varroa destructor, which is actually the second cause of death for european bees. Indeed, up to 50% of the swarms are lost every year, partly because of these parasites, causing tremendous economic damages to beekeepers, as well as psychological ones. This year, our team is committed to preserving honeybees by fighting these mites. The aim of our project is to work out a bacteria capable of baiting and eliminating the parasite by using the tools offered by synthetic biology. Our bacteria, named ApiColi, will be capable of expressing alternatively an attractant and a poison for the varroa, in agreement with the honeybees’ cycle of life. Our trap will be sealed to avoid any contact of the microorganism with the environment. We hope that our concept will help reduce the decrease in bee populations and its disastrous consequences.