Interesting where science takes us, isn’t it? One entomologist conducted an experiment on the Death-Watch beetle. That experiment led to another, and another, and suddenly he figured out a foolproof way to get the male beetle a little nookie.

The Death-Watch beetle isn’t as fearsome as its name makes it sound (unless you’ve seen Practical Magic). It used to be at least worrying. The beetles slowly, slowly chew through dead wood. They’re small and they don’t do much damage, but the damage adds up. Very old buildings have seen roof collapses due to hundreds of generations of this little beetle.


At least it’s easy to figure out if you’ve got a Death-Watch infestation. When the beetle decides it’s time to mate, the male knocks his head against the wood, making a loud rapping noise. The female answers. The male raps again. They navigate towards each other and get together.

Dave Goulson, a biologist, wanted to figure out how the two beetles found each other, given that they were too small and too awkwardly positioned to make use of the sound the way we do. The answer isn’t interesting (the male walks in a random direction and if the rapping gets louder, he keeps walking), but the question did lead to Goulson watching a lot of beetle sex. He noticed that the female outright rejected the male much of the time. She always rejected the smaller males. This made little sense. Being big isn’t necessarily an advantage if your life involves nothing but crawling around dead wood avoiding predators, and the male was hardly going to stay around and protect his offspring.

Goulson decided to weigh the males before and after each encounter. He found out that they lost up to one-fifth of their weight during sex. Females were rejecting males who were too light because they had they had too little, ahem, love to give


The all-purpose, sure-fire, can’t-fail solution to poor celibate males? Blu-Tack, that putty-like adhesive people use to hang posters on walls. Put a little dab of Blu-Tack on a male’s back to get his weight up, and suddenly females were all about letting him mate with them. Goulson had found the ultimate Death-Watch aphrodisiac. Now you know it, too. Who knows? It may save your life some day.

Image: Gilles San Martin

[Source: A Buzz in the Meadow, Dave Goulson]