There’s no place like home

Birthplace exerts a lifelong influence on butterflies as well as humans, new research suggests.

In a paper published in the journal Proceedings of the Royal Society B: Biological Sciences, Darrell Kemp from Australia’s Macquarie University describes how the American passionfruit butterfly (Heliconius charithonia) selects its mate and egg-laying site based on the species of plant that hosted its own egg.

It is, Kemp says, the first evidence that conditions in very early life for butterflies determine adult behaviour – something many researchers previously thought impossible.

H. charithonia feed and lay eggs on more than 20 species of plants, but all belong to a single genus, Passiflora.

Kemp collected 38 wild females butterflies that had been breeding exclusively on a passionfruit species known as Passiflora incarnarta, then randomly assigned their eggs to either P. incarnarta plants or the related P. suberosa.

He found that females raised in P. suberosa tended to mate with males which had grown up on the same species, then tended to lay eggs on it as well. This was the case even though P. incarnarta generation members were on the whole larger and developed more rapidly.

“Males as well as females were influenced by their birthplaces, which in insects is really unusual,” he says.

“It’s possible that this sort of preferential behaviour could influence the development of distinct and isolated populations – and perhaps eventually new species.”