MEDFORD/SOMERVILLE, Mass. (June 25, 2012) The twinkling of fireflies heralds summer romance for these magical insects. While courting on-the-wing, male fireflies attract females' attention with bioluminescent flashes.
But new research from biologists at Tufts University's School of Arts and Sciences, published online in Proceedings of the Royal Society - Biological Sciences, reveals that, after the lights go out, female fireflies prefer substance over flash. They seem to choose mates able to give them the largest "nuptial gift" (a high protein sperm package that helps females produce more eggs) without regard to flashes. Those generous males are also more likely to succeed in becoming the fathers of the next firefly generation.
Previous work on Photinus fireflies shows that females are very picky during the on-wing stage of courtship. These females will only flash a response toward select males that light up with especially attractive courtship flashes. After a lengthy back-and-forth exchange, the flashing stops, the lights go out, and firefly pairs spend the night together.
A night of firefly romance also includes gifts, called spermatophores, that each male donates to his sweetheart. But the next night these females are likely to mate again with a different male.
After a female has mated with several males, the big evolutionary question becomes: which male gets to pass along his genes to the next generation of firefly babies?
"Lots of people don't realize that sexual selection is happening not only before mating, but also during and even after mating," said Professor of Biology Sara Lewis, an expert on the evolutionary process of sexual selection and senior author on the paper. "Focusing on what happens after contact, we wanted to examine how much a male's success -- in both mating and fathering offspring -- depended on his flashes or on his nuptial gift offering."
Lewis and coauth
|Contact: Kim Thurler|