Garlic is not a substance that most people consider to be an aphrodisiac. It turns out the mosquitoes agree too.
In fact, a new study from Yale University found that garlic also acts as a de facto contraceptive for mosquitoes and other winged insects, an insight that could lead to eco-friendly pest control strategies.
Research by John Carlson’s lab at Yale University shows that there are garlic blocks that mate with mosquitoes and various fly species. Researchers have discovered that it’s not the pungent odor that these pests dislike, but the taste. The reason lies in the receptors inside their tiny taste organs. Research results will be published in a magazine cell.
We study flies, including harmless flies like fruit flies, to discover new ways to control species that pose a danger to humans by spreading disease and damaging crops. In this study, we started with fruit flies and then moved on to other species. And to their surprise, they discovered that garlic contains a natural compound that stops the mating process in these flies. ”
John Carlson, Eugene Higgins Professor of Molecular, Cellular, and Developmental Biology, Yale School of Arts and Sciences
Their method of discovering this compound, which they call “phytoscreen,” could facilitate new pest control strategies that are environmentally friendly, widely available, and inexpensive. Phyto means “plant” in Greek.
In a Q&A, Carlson explains the role of an enterprising postdoc in starting this research, how it started with a “fruit fly buffet,” and why Victorian author Bram Stoker was right about garlic and bloodthirsty creatures.
The interview has been edited for length and clarity.
What was the impetus for this project?
John Carlson: Our lab has a project to study the receptors and neural circuits that drive reproductive behavior in insects, using Drosophila melanogaster as a model organism. Simaa Ebrahim, an associate researcher in the lab, wondered if there might be something in fruits and vegetables that acts as an aphrodisiac and stimulates mating, since fruit flies usually mate on fruits. So she went to the supermarket and bought 43 different types of fruits and vegetables. She made a puree from each and placed it in a Petri dish for the flies to sample. It was a kind of fruit fry buffet.
What did you expect?
Carlson: Simaa believed that at least one of these fruits would provide a significant boost in mating. I was wondering if it might act as a kind of aphrodisiac. But no one did. The surprising result was that garlic completely abolished hybridization. Egg laying was also inhibited.
Was it the smell or the taste?
Carlson: We wondered that too. So Simaa cleverly positioned the garlic puree so that the flies could smell it but not taste it, or so the flies could smell and taste both. Turns out it was the taste. Shimaa is a very careful scientist, so he double-checked his findings. She went to another grocery store, got the same 43 fruits and vegetables, and ran the test again. And I got exactly the same results with different garlic bulbs. Garlic inhibited mating by 100%. They then tested other flies, including the tsetse fly, and found similar results.
What is it about garlic that is so opposed to flies?
Carlson: We isolated the chemicals in garlic puree and found that the culprit was a chemical called diallyl disulfide. Mating and spawning are prohibited. I was happy to discover that diallyl disulfide is already used in all kinds of foods. It is used as a food flavoring and as an ingredient in a variety of nutraceuticals and dietary supplements.
What does diallyl disulfide do to flies?
Carlson: We found that a sensory receptor in the fly’s taste organ called TrpA1 detects this compound, triggering avoidance behavior in the fly. This makes sense because TrpA1 may function as a type of taste receptor. They also found that garlic activates specific bitter-sensing neurons containing TrpA1, which changes the expression of genes, including those associated with satiety.
Did it block the mating urges of both sexes?
It primarily affected female flies.
What are the potential broader applications revealed by this study?
There are two. First, garlic was found to prevent two species of mosquitoes that spread deadly diseases such as yellow fever, dengue fever, and the Zika virus from mating and laying eggs. Interestingly, it had no effect on wasps, which puzzled us until we discovered that wasps do not have TrpA1 receptors.
A second possible use is that this general approach (testing inexpensive, human-edible fruit and vegetable purees) could be used to find compounds that block other behaviors in other harmful organisms. Agricultural crops contain a huge variety of compounds, and Shimaa has invented a simple method to identify useful compounds.
Some commercial gardening products already use certain plant-based pest control agents. How is this different?
Carlson: Some products containing garlic are already available for purchase, which is consistent with our findings that insects do not like garlic. But what we have discovered is the “why”. And now that we know how to easily look for natural compounds that act as deterrents for insects, the door is open to all kinds of possibilities.
Any other lessons learned?
Carlson: We learned quite a bit about garlic by doing this research. It is cheap and grown all over the world. Cultivated for thousands of years, it was discovered in the tomb of Tutankhamun and has been used for medicinal purposes since the time of the Roman Empire.
The concept of using garlic to deter blood-sucking creatures was proposed by Bram Stoker in 1897 in his novel Dracula. Maybe he realized something.
What did Yale University researchers discover about garlic and mosquitoes?
Compounds in garlic act as a type of contraceptive against mosquitoes and other flying pests. The presence of garlic blocks the mating and oviposition responses of various fly species. Receptors in the flies’ taste organs detect garlic compounds and cause them to stop breeding. The researchers used a “phytoscreen” to test insect responses to different plants. Phyto means “plant” in Greek.
Have backyard gardeners known for years that garlic can help deter pests??
they have. A team from Yale University has figured out why. This is an important step because researchers now know how to easily identify natural compounds that act as insect repellents, potentially opening the door to new products that are natural, cheap, and readily available.
What other types of flies are garlic effective against?
Garlic stopped two species of mosquitoes, which spread diseases such as yellow fever, dengue fever and Zika virus, from mating and laying eggs. It was also effective against tsetse flies and fruit flies.
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Reference magazines:
Ebrahim, S.A.M. Others. (2026). Phytoscreening identified garlic compounds as inhibitors of mating and oviposition in fruit flies and mosquitoes. cell. DOI: 10.1016/j.cell.2026.03.037. https://www.cell.com/cell/abstract/S0092-8674(26)00338-7
