A 2013 PLOS ONE study revealed the oldest example of insect sex ever discovered. The fossil dates to the mid-Jurassic Period, about 165 million years ago.
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Credit: Su Li and Chungkun Shih; line drawing by Su Li
The two love bugs were caught indiscretely, with the sex organ of the male clearly inserted into the female's bursa copulatrix.
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Credit: Oregon State University
Examples of fossilized insect sex are quite rare, with only about 40 specimens found around the world. Most are trapped in amber, like this spider attack.
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Credit: Li et al, PLOS ONE 2013
Modern froghopper genitalia doesn't look too different from that of the ancient love bugs.
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Credit: Art by Chen Wang
Sex hasn't changed much in the intervening years either. Modern froghoppers also like to mate face-to-face when clutching a small twig or shoot.
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Side by Side
Credit: Janson Shih
Modern froghoppers may also mate side by side if they are on a leaf or a tree trunk.
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Tia has interned at Science News, Wired.com, and the Milwaukee Journal Sentinel and has written for the Center for Investigative Reporting, Scientific American, and ScienceNow. She has a master's degree in bioengineering from the University of Washington and a graduate certificate in science writing from the University of California Santa Cruz. To find out what her latest project is, you can follow Tia on Google+.