The coffee berry borers are the Cersei and Jamie of the insect world, and the number one place of choice for their incestuous escapades is inside your coffee beans. Discovery News has called this tiny bug the “most serious pest of coffee plants worldwide,” and although there isn’t any serious harm from drinking coffee that has been infested by these bugs, in case you prefer drinking coffee that insects haven’t had sex in, here’s what you should know.

The tiny insects eat holes into the beans, where they then lay their eggs. Once hatched, the larvae eat the inside of the bean, lowering the quality of the actual coffee and thus reducing income for farmers, the USDA reported.

"The insect can cause coffee farmers to lose up to 20 percent of a crop and reduce the price by 30 to 40 percent," said Ted Lingle, executive director of the Specialty Coffee Association of America, to the USDA. "Damage from the borer hurts every coffee-producing country in the world."

A new study has uncovered an even more disturbing fact about these tiny little pests. Not only do they lay their eggs into the beans, but they also have sex with their siblings inside of them. Females have to mate their siblings in order to maximize their chances of successful colonization, reads the study, even though sexual reproduction isn’t even necessary for this species. They have been observed to reproduce on their own via a process call parthenogenesis, The Week reported.

Discovery News reported that most of the infected coffee beans are removed and never reach your local supermarket, but in case a few do make it through, here’s what to look for.

The female beetles will bore tiny little holes in the beans in order to escape, so the beans may be more hollow than usual. Also, the site warned that Coffee Arabica is their favorite, so if this is your go-to bean, you may be at a slightly higher risk for bug infestation.

The bugs are not only detrimental to the coffee beans but also have serious social implications.

"It's important to protect the economic viability to grow the crop; there are millions of people throughout the world who depend on coffee production for their subsistence," said Fernando E. Vega on the USDA page for the coffee pest.

Source: Dias Silva W, Moura Mascarin G, Manesco Romangnoli E, Simoes Bento JM. Mating Behavior of the Coffee Berry Borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae). Journal of Insect Behavior. 2014.