In January 1942, the leader of the SS, Heinrich Himmler, ordered the creation of the Dachau entomological institute. Its official mission was to find new remedies against diseases transmitted by lice and other insects: German troops were often plagued by typhoid, and there were concerns about a developing typhoid epidemic at the Neuengamme concentration camp.

But in an article for the science journal Endeavour, Klaus Reinhardt says protocols kept by the head of the institute allow no other conclusion than that the institute also pursued research into biological warfare.

In 1944, scientists examined different types of mosquitoes for their life spans in order to establish whether they could be kept alive long enough to be transported from a breeding lab to a drop-off point. At the end of the trials, the director of the institute recommended a particular type of anopheles mosquito, a genus well-known for its capacity to transmit malaria to humans.

With Germany having signed up to the 1925 Geneva protocol, Adolf Hitler had officially ruled out the use of biological and chemical weapons during the second world war, as had allied forces. Research into the mosquito project had to be carried out in secret.