The tick, an easy prey for ants, can detect its proximity thanks to chemical signals. This comes from a study that suggests that the same signals could be used in humans as a defense against insects, certain species of which are vectors of diseases such as Lyme.
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In the United States, Ixodes scapularis, also called the deer tick, feeds on its blood. If she doesn't succeed, she resorts to the person passing by. There is a risk that Lyme disease, whose symptoms range from simple itching to neurological disorders, may also be transmitted among the transmitted pathogens.
In Europe, Ixodes ricinus, a cousin, plays the role of the vector of this pathogen.
In both cases, the insect prefers a habitat of undergrowth or tall leaves that protect it from the sun. But it shares it with other species, including one of its predators, the ant.
The latter uses an arsenal of chemical signals to coordinate the defense of its nest or the gathering of food. Signals that spiders or bees know to recognize in order to better avoid a dangerous encounter. But ticks?
We didn't know about it until the study was conducted by a team of researchers at Canada's Simon Fraser University and published Wednesday in the Royal Society Open Science
They hypothesized that a species of ant common in Canada, Formica oreas, sent out a combination of its usual venom, formic acid and pheromones that marked its territory as an alarm signal.
And the study states that a tick was able to recognize these signals, which are of great importance around an ant nest.
The researchers tested their hypothesis by putting ticks in a small container with two short tunnels, each leading to another container, the bottom of which was a paper filter that was neutral on one side and soaked in chemical signals from ants on the other .
Ticks responded strongly to the combination of venom and pheromones, as well as to their artificial versions. On the other hand, the effect of the individual components was not convincing when viewed in isolation.
The researchers do not rule out that the tick also perceives other signals from the ants, such as those from the submandibular glands. They are used by other species of ants to warn their fellow ants, and some of their organic compounds are found in essential oils used as tick repellents.
Scientists at Simon Fraser therefore want to test a combination of all these ingredients as a repellent that humans can use against ticks.