These Moths Remember Where They Mated for the First Time

The locale of the African cotton leafworm moth’s first experience pairing up forms its future preferences, a new study shows

Leafworm moth
An African cotton leafworm moth. Nir Ofir, via Wikimedia Commons, CC-BY-SA 2.5

They say you’ll always remember your first time—and according to a new study that's actually true for the (presumably unsentimental) African cotton leafworm moth.

As Penny Sarchet reports for New Scientist, research shows that these moths show a preference for the kind of plant where they mated for the very first time and will return to that plant species to mate again.

In the wild, cotton leafworm moths, which are found throughout Africa and in parts of Asia and Europe, can pick from a number of mating and egg-laying locales, but they are known to have an innate preference for cotton plants. So, in a series of experiments, scientists had the moths copulate for the first time on cabbage leaves and then checked to see if they showed a preference to cabbage over cotton for their second mating and egg-laying experience. Turns out, they did.

And the moths don’t seem to show preference to just to any place they’ve been before—“mating has to be involved,” writes New Scientist.

“A familiar environment only does not work—plant exposure has to be coupled with mating," the study’s lead author, Magali Proffit told Sarchet. “Perhaps we could see it this way: if something worked well in a particular place, why not visit it again?” And then there’s this comparison:

Sean Prager of the University of California, Riverside, likens the moth's behaviour to a visit to a city's Chinatown district. "There are many restaurants, likely they will serve similar food, and most of it will be suitable," he says. "However, if you have been to one in the past and know it is good, you may choose to return to that one."

How romantic.

The study also looked at the sites where the moths fed as larvae and found that the plant on which a moth caterpillar grew up can shape its preferences, too. (They did not, however, look at whether later mating experiences changed moths' preferences.)

By moth standards, finding the same plant to mate on each copulation cycle might sound complicated. But the gold swift moth takes even more extensive measures for sex. National Geographic deemed it to have “the most elaborate mating system so far known in insects,” as it employs courtship strategies and multiple sexual positions. 

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