On Friday night, U.S. companies released hundreds of thousands of mosquitoes into the environment of Montreal as a biological control effort targeting the invasive tiger mosquito. The operation, timed for the early hours of 7 August 2026, is intended to lower the numbers of the species that is known to transmit viruses such as dengue, chikungunya and Zika.
The release was coordinated with input from Étienne Normandin, an entomologist at the Institut de recherche en biologie végétale, University of Montreal. Normandin explained that the strategy relies on flooding the area with large numbers of sterile or otherwise modified mosquitoes, which compete with the disease‑carrying tiger mosquitoes for breeding sites and mates, thereby reducing the overall population.
Tiger mosquitoes, originally native to Asia, have become an invasive pest across North America in recent years. Their ability to thrive in urban environments and bite during daylight hours has facilitated the spread of several viral illnesses previously uncommon in the region. Public health officials have highlighted the growing risk of outbreaks linked to these vectors, prompting experimental control measures such as the one carried out in Montreal.
The deployment of hundreds of thousands of insects represents a significant step in the ongoing effort to manage the species without relying on chemical insecticides. While the long‑term impact of the release will be monitored, officials hope the approach will lead to a measurable decline in tiger mosquito numbers and consequently lower the risk of disease transmission in the city and surrounding areas.