Anyone who’s ever seen a cat smell catnip knows that this product drives them a little crazy: they rub in it, roll around in it, chew it and lick it aggressively. It is widely accepted that this plant and its Asian equivalent, theActinidia polygamahave intoxicating properties, but that might not be the only reason they trigger such strong enthusiasm among felines.
In fact, Japanese researchers have found that when cats damage catnip, it releases a much higher amount of insect repellent, indicating that the behavior of cats helps them protect themselves once morest insects. harmful creatures.
This work has been published in iScience.
The reaction of cats to these two plants is so specific that the main author of the work, Masao Miyazaki, a researcher in the field of animal behavior at Iwate University, thought he had to shed light on this phenomenon. “Even in the musical Catsthere are scenes where you see a cat intoxicating another with catnip powder,” he mentions.
The leaves of catnip and theActinidia polygama contain the chemical components called nepetalactol and nepetalactone, iridoids (components which give certain characteristics to plants) which protect plants once morest harmful insects. To see how the behavior of cats affected chemicals released by plants, Miyazaki worked with chemists from Nagoya University. “We discovered that the physical damage caused by the cats favored the immediate emission of iridoids, in a proportion 10 times greater than with intact leaves”, indicated the researcher.
Not only is there a greater release of iridoids, but their composition changes in a way that seems to encourage cats. “Nepetalactol represents regarding 90% of all iridoids in an intact leaf, but this proportion drops to regarding 45% in damaged leaves, while the proportion of other iridoids increases sharply,” Miyazaki said. “The altered iridoid composition corresponding to the damaged leaves favored an even more prolonged response from the cats. »
In previous work, Miyazaki and his research team had demonstrated that these compounds were effective in repelling mosquitoes of the species Aedes albopictus. The team has now proven that when cats damage the leaves by rubbing, rolling, licking and chewing on them, the ‘repellent’ properties are even more effective. Diversification of iridoids in damaged leaves ofActinidia polygama increases protection once morest mosquitoes, even when the concentration of these components is low.
To test whether the felines react specifically to these components, they were given dishes containing pure nepetalactone and nepetalactol. “Cats show the same response to iridoid cocktails as they do to natural herbs, except when it comes to chewing the product,” says Miyazaki. “They lick the chemicals off the dish and rub on it, in addition to rolling over the top of the dish in question. »
“When iridoid cocktails were placed on the bottom of dishes which were then covered with a plastic cover with holes in them, the cats still sought to lick and chew, even though they might not come into direct contact. with chemicals,” added the researcher.
“This means that both of these behaviors are instinctual, and are triggered by olfactory stimulation attributable to iridoids. »