Taste system is crucial in controlling insect behavior. There is still much to learn about the tastants that mosquitoes encode and their influence on essential behavior.
Yale researchers discovered that taste affects mosquitoes biting behaviour. The findings could help develop new ways to prevent mosquito bites, and possibly stop the spread of disease they can carry.
Recently, researchers have discovered how mosquitoes encode different tastes by their neurons, which can influence behaviors such as biting, eating, and laying eggs. This study identified compounds found in sweat of humans that increase biting by mosquitoes and bitter compounds which suppress egg-laying and feeding. The study offers new insight into the reasons why certain people are attracted more to mosquitoes.
The study focuses on the Asian Tiger Mosquito, which is found in six continents and has spread globally. It highlights its role in the transmission of diseases such as dengue and Chikungunya. This mosquito is a growing threat to the public’s health as it outcompetes all other species.
Researchers tested 46 taste compounds on the Asian Tiger mosquito, including salts, sugars and bitter compounds. The researchers observed the response of neurons within the taste organ to different compounds. Results showed that some compounds like sugars activated many neuronal activities, while others inhibited it.
John Carlson, senior author and Eugene Higgins professor of Molecular, Cellular, and Developmental Biology at Yale’s Faculty of Arts and Sciences, stated: We’ve studied the taste of fruit flies extensively, but we’ve never seen such widespread inhibition in flies before. The mosquitoes’ ability to differentiate tastes is enhanced by these two responses, excitation and inhibitory.
Researchers also looked at how taste compounds affected mosquitoes biting, eating, and egg-laying behavior. The researchers found that specific tastes either increased or decreased certain behaviors. Bitter compounds, for example, reduced egg-laying but not feeding. While salt and amino acid compounds found in sweat of humans had no effect on bites individually, when they were combined, the effects increased.
The combination of amino acids and salt in sweat is likely to explain why mosquitoes prefer human skin. Researchers suggest that mosquitoes are able to detect the unique combination and recognize it as an ideal spot for biting. Researchers also found that mosquitoes preferred some human sweat samples to others when they presented them with the samples. This suggests that mosquitoes are attracted by certain compositions of sweat.
Carlson stated that We think that this may be a reason why some people get more mosquito bites than others. “Some people might just be more appealing to mosquitoes.”
Notes by Researchers Together, these findings describe the decision-making process of mosquitos who have touched down to decide if they will bite or flee. This information could help to identify compounds which encourage mosquitoes not to bite but instead fly away.
Journal Reference
- Baik, L.S., Talross, G.J.S., Gray, S. et al. Biting and feeding are guided by mosquito taste responses. Nature 635: 639-646 (2019). DOI: 10.1038/s41586-024-08047-y
