A study from the University of Sao Paulo published in the Journal of Insect Behavior describes the shocking behavior of coffee berry borers. These insects, which Discovery News calls "the most serious pests of coffee plants worldwide," have sex in coffee beans before they're roasted into the delicious drink.
The coffee berry borers are a type of beetle native to Africa. The females are just .07 inches long, and the males are about .06 inches long — tiny enough to get down inside coffee beans.
That's not even the weirdest part — the beetles' coffee bean sex is also incestuous. Weliton Dias Silva, author of the study, writes that females "have to be copulated by their sibling males before leaving the native coffee fruit to improve their chances of successful colonization." And sometimes, females don't even need their brothers — they can reproduce on their own, through parthenogenesis.
The Week
Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.
Sign up for The Week's Free Newsletters
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
So how can you tell if your coffee beans are the site of insect sex? Discovery News reports that the female beetles bore "minute holes" to escape from the beans, and the beans may also seem more hollow than others. If you're a fan of Coffee arabica, you might be more at risk — it's also the beetles' coffee of choice. You probably shouldn't be too concerned, though, because most of the "infested" beans are taken off the market.
Read more about the coffee berry borers — and view close-up photos of the insects, if that's your thing — over at Discovery News.
-
September 14 editorial cartoonsCartoons Sunday’s political cartoons include RFK Jr on the hook, the destruction of discourse, and more
-
Air strikes in the Caribbean: Trump’s murky narco-warTalking Point Drug cartels ‘don’t follow Marquess of Queensberry Rules’, but US military air strikes on speedboats rely on strained interpretation of ‘invasion’
-
Crossword: September 14, 2025The Week's daily crossword puzzle
-
SpaceX breaks Starship losing streak in 10th testspeed read The Starship rocket's test flight was largely successful, deploying eight dummy satellites during its hour in space
-
Rabbits with 'horns' sighted across Coloradospeed read These creatures are infected with the 'mostly harmless' Shope papilloma virus
-
Lithium shows promise in Alzheimer's studySpeed Read Potential new treatments could use small amounts of the common metal
-
Scientists discover cause of massive sea star die-offSpeed Read A bacteria related to cholera has been found responsible for the deaths of more than 5 billion sea stars
-
'Thriving' ecosystem found 30,000 feet underseaSpeed Read Researchers discovered communities of creatures living in frigid, pitch-black waters under high pressure
-
New York plans first nuclear plant in 36 yearsSpeed Read The plant, to be constructed somewhere in upstate New York, will produce enough energy to power a million homes
-
Dehorning rhinos sharply cuts poaching, study findsSpeed Read The painless procedure may be an effective way to reduce the widespread poaching of rhinoceroses
-
Breakthrough gene-editing treatment saves babyspeed read KJ Muldoon was healed from a rare genetic condition
