New research published in iScience reveals that different mosquito species have distinct preferences when it comes to choosing human hosts. The study, conducted in Miami, Florida, tested the attraction of three mosquito species—the yellow-fever mosquito (Aedes aegypti), the Asian tiger mosquito (Aedes albopictus), and the southern house mosquito (Culex quinquefasciatus)—to 119 volunteers.
Mosquitoes locate their hosts using a combination of signals, including carbon dioxide, body odour, heat, humidity, and visual cues. Human scent is a complex mixture of hundreds of volatile compounds, some of which are produced or modified by bacteria living on the skin. These differences allow mosquitoes to distinguish between individuals.
The researchers found that while some people were highly attractive to more than one mosquito species, no one in the study was among the most attractive to all three. In other words, being particularly appealing to one species did not necessarily mean being appealing to another.
“We didn’t expect the species to prefer different people when we started the study,” said Kaylee Marrero, the study's lead author, in a press release. “Each species having a distinct microbial signature that they use as a cue was so surprising to me.”
Distinct preferences per species
The yellow-fever mosquito showed a slight preference for male participants and was associated with particular patterns of volatile compounds and skin bacteria. The Asian tiger mosquito was drawn to elevated ketones and plant-like volatile compounds naturally secreted by the skin. The southern house mosquito, which is active at night, was attracted by the microscopic ecosystem of bacteria, fungi, and microbes living on people’s skin.
Understanding these cues could help scientists develop more targeted strategies against diseases spread by mosquitoes, including dengue, Zika, yellow fever, and West Nile virus. “Isolating the components of human odor that attract or repel mosquitoes could lead to novel strategies to combat vector-borne diseases,” said Matthew DeGennaro, a neurogeneticist who leads the research team and directs the Biomolecular Sciences Institute at FIU, Miami’s state university.
The three species tested are not equally relevant to Europe. The Asian tiger mosquito is now established across large parts of the continent, including Austria, Belgium, Bulgaria, Croatia, Cyprus, France, Germany, Greece, Hungary, Italy, Malta, Portugal, Romania, Slovakia, Slovenia, and Spain. According to the European Centre for Disease Prevention and Control (ECDC), the species has undergone a dramatic global expansion facilitated by human activities, and climate change is expected to allow it to continue spreading beyond its current boundaries. This expansion has already led to surges in mosquito populations in Germany and elsewhere.
The yellow-fever mosquito has a much more limited European distribution, according to ECDC maps. The southern house mosquito is generally absent from mainland Europe, preferring tropical and subtropical regions.
The researchers stress that the study was conducted under laboratory conditions and does not prove that a particular person would necessarily receive more mosquito bites in the real world. Field studies will be needed to determine how closely the laboratory rankings correspond to actual biting behaviour.
These findings add to a growing body of research on how climate change and global trade are reshaping Europe's insect populations. As invasive species like the Asian tiger mosquito expand their range, understanding their host preferences becomes crucial for public health planning across the continent.
