Mosquitoes are often perceived solely as irritating pests, yet their presence in nearly every terrestrial ecosystem worldwide belies a complex role. These small insects are well-known for their blood-feeding habits, which can transmit serious diseases to humans and animals. However, they also participate in ecological processes that contribute to biodiversity. The question of whether to eradicate mosquitoes, or at least disease-transmitting species, involves a multifaceted scientific debate considering their negative impacts and ecological contributions.
Global Health Impact
Mosquitoes are responsible for transmitting a range of devastating diseases, making them one of the deadliest animals globally. Malaria, transmitted by Anopheles mosquitoes, caused an estimated 263 million cases and 597,000 deaths worldwide in 2023, with children under five in the WHO African Region bearing a disproportionately high burden. Dengue fever, spread by Aedes mosquitoes, reached over 6.5 million cases and 6,800 deaths in 2023, with a surge to nearly 4.7 million cases and over 5,300 deaths in the first half of 2024. The Zika virus, also primarily transmitted by Aedes aegypti, saw over 25,000 cases in the Americas in 2024, particularly due to its association with microcephaly in infants.
West Nile virus, carried by Culex mosquitoes, resulted in 2,770 reported cases, over 2,000 hospitalizations, and 208 deaths in the U.S. in 2023. Yellow fever, another Aedes-borne disease, saw 61 confirmed cases and 30 deaths in the Americas in 2024, with a significant increase to 212 cases and 85 deaths reported by late April 2025. The economic burden of these diseases is substantial, estimated at around $12.4 billion annually globally, straining healthcare systems and causing productivity losses. Malaria alone can reduce a country’s Gross Domestic Product (GDP) by up to 1.3% in highly affected regions.
Ecological Contributions
Despite their public health threat, mosquitoes fulfill various roles within ecosystems. Both male and female mosquitoes primarily feed on nectar from flowers for energy, inadvertently transferring pollen as they move between plants. This makes them pollinators for thousands of plant species, including certain orchids like the blunt-leaf orchid (Platanthera obtusata) and goldenrods. While they may not be as efficient as bees, their collective activity contributes to plant reproduction.
Mosquitoes also serve as a food source for numerous animals across different life stages. Mosquito larvae, which develop in water, are consumed by fish, frogs, newts, and aquatic insects like dragonfly nymphs, contributing significantly to the biomass of aquatic food webs. Adult mosquitoes are prey for birds, bats, spiders, and other insects such as dragonflies. Some bat species can consume hundreds to over a thousand mosquitoes in a single hour. Their abundance makes them a readily available and nutrient-rich food source for these predators, supporting various trophic levels within ecosystems.
Practicalities of Elimination
Attempting a global eradication of mosquitoes presents immense practical and ethical challenges. There are over 3,500 mosquito species, and only about 100 transmit human diseases, making targeted elimination complex. A global campaign would require vast financial resources and international coordination. The total economic cost related to invasive Aedes mosquitoes alone was estimated at over $95 billion between 1975 and 2020, primarily due to disease treatment rather than prevention efforts.
Unforeseen ecological consequences are a significant concern. Removing a species could leave an ecological niche vacant, potentially leading to other species, perhaps even more problematic ones, filling that void. While some argue that many species that prey on mosquitoes could adapt to other food sources, the removal of a substantial food base could disrupt local food webs, affecting populations of fish, birds, and other insectivores. The widespread use of pesticides for eradication would also pose a broad threat to non-target species and could have long-term environmental impacts. Ethical considerations also arise from intentionally driving an entire biological group to extinction, even one perceived as a nuisance, given the inherent value of biodiversity and the potential for unintended cascading effects.
Managing Mosquito Populations
Instead of outright eradication, current efforts focus on managing mosquito populations and mitigating disease transmission. Traditional methods include insecticide-treated nets (ITNs) and indoor residual spraying (IRS). ITNs reduce malaria incidence and child mortality in endemic regions. IRS involves spraying long-lasting insecticides on indoor surfaces, killing mosquitoes that rest there after feeding and effectively reducing disease transmission.
Environmental management strategies involve eliminating mosquito breeding sites by draining standing water, managing irrigation, and removing containers where water can collect. Biological control methods utilize natural enemies, such as the Gambusia affinis (mosquitofish) which consume larvae, or bacteria like Bacillus thuringiensis israelensis (Bti) that produce toxins specific to mosquito larvae. Advanced techniques include using Wolbachia bacteria, which can be introduced into Aedes aegypti mosquitoes to reduce their ability to transmit viruses like dengue and Zika, and are self-sustaining in wild populations. Gene-editing technologies, such as gene drives, are also being explored to suppress mosquito populations or render them incapable of disease transmission, but these raise ongoing ethical debates regarding their release and potential ecological impacts.