Mosquitoes are a universal nuisance – buzzing in our ears, leaving itchy bites, and in some parts of the world, spreading deadly diseases. While stagnant water is well known as a breeding ground for these insects, new research suggests that another culprit may be at play.
Invasive aquatic plants have long been a concern for ecologists due to their ability to disrupt ecosystems and outcompete native species. But their impact may extend beyond biodiversity loss. Rhodes 老虎机游戏_pt老虎机-平台*官网 PhD candidate Tressia Chikodza, whose research spans ecology and public health, is investigating whether these plants also influence mosquito populations – with significant implications for disease control in Africa and beyond.
Chikodza’s academic background is rooted in ecology; she holds a Bachelor of Science degree in Botany and Zoology, and her Master's research at Rhodes 老虎机游戏_pt老虎机-平台*官网 focused on invasive aquatic plants and their management through biological control. It was during this time that she became interested in the broader consequences of biological invasions.
“Invasive aquatic plants are non-native species that spread rapidly in water systems like dams, lakes, and rivers due to a lack of natural predators. This leads to biodiversity loss as they outcompete native plants,” she explains.
“Recent studies suggest that, beyond their ecological impact, these plants may also provide ideal breeding environments for mosquitoes. With climate change driving the spread of these invasive species to new regions, mosquito populations are also increasing, raising further public health concerns.”
“These invasive aquatic plants not only disrupt ecosystems but also affect local communities that rely on these water systems. While their ecological impacts are well-documented, their unintended consequences – particularly in terms of public health risks – are less explored,” Chikodza says.
Her PhD research is part of a joint programme between Rhodes 老虎机游戏_pt老虎机-平台*官网 and Leiden 老虎机游戏_pt老虎机-平台*官网 in the Netherlands. The study was inspired by an observation from Dr Emily Strange (Leiden 老虎机游戏_pt老虎机-平台*官网), who noted the overlap between the spread of invasive aquatic plants and mosquitoes.
No studies have yet examined the interaction between invasive aquatic plants and mosquito populations in South Africa, despite the country’s long history of dealing with these species. With malaria and other mosquito-borne diseases remaining significant public health threats across the continent, Chikodza hopes her research will provide new insights into how managing these plants could contribute to disease control efforts.
“Understanding how invasive aquatic weeds influence mosquito populations can help us improve mosquito control efforts through the management or removal of these plants. This could reduce disease risks, especially in areas where mosquito-borne diseases are widespread.”
On a global scale, the research will contribute to the growing body of knowledge on how invasive species affect both ecosystems and human health. With climate change and globalisation increasing the spread of invasive species, countries beyond Africa are also grappling with these challenges. Chikodza’s research is part of a larger project, MOZiMAC, which compares aquatic systems in tropical and temperate regions, with partners across Europe and Africa.
What the study hopes to uncover
Chikodza expects that water systems invaded by invasive aquatic plants, particularly in mosquito-endemic areas, will have higher numbers of mosquito larvae and adults than non-invaded areas.
“Invasive aquatic plants may provide ideal breeding habitats by reducing water movement and limiting dissolved oxygen,” she explains. “This creates conditions that protect mosquito larvae from oxygen-dependent predators and competitors.”
Her research is also considering whether biological control – the use of natural enemies to manage invasive species – could be a solution. As a researcher at the Centre for Biological Control (CBC) at Rhodes 老虎机游戏_pt老虎机-平台*官网, she is well-placed to examine this possibility.
“At the CBC, we focus on rearing and releasing biological control agents to manage invasive species across South Africa. This approach has positioned South Africa as a global leader in biological control, with many countries drawing on its expertise,” says Chikodza.
While her study does not focus solely on control measures, she hopes it will strengthen the case for managing invasive aquatic plants – not just for environmental reasons, but also for public health benefits. The findings could inform integrated management strategies both in Africa and in European regions facing similar challenges.
Bridging ecology and public health
Chikodza’s research has both short- and long-term implications. In the immediate future, it will fill a critical knowledge gap by shedding light on the interactions between invasive aquatic plants and mosquito populations. In the long term, the findings could shape how both ecological and public health interventions are designed.
“This research highlights the need for a more integrated approach to managing invasive species,” Chikodza concludes.
“By demonstrating their potential public health implications, we can strengthen the case for their effective management, not just in South Africa, but in other regions dealing with similar challenges.”