Scientists find Achilles' heel of coffee fruit beetle

A new study published in Nature Communications on July 14 shows that coffee fruit beetles, a harmful coffee pest, break down caffeine through intestinal flora, according to a new study published in Nature Communications on July 14. Without these intestinal flora, caffeine is toxic to coffee bark beetles, and this newly discovered intestinal flora may provide new strategies to help control the pest.

Coffee bark beetle is a worldwide coffee pest that reduces coffee production by 80%. It is the only insect known to complete its life cycle only in green coffee beans. However, the basic metabolism of this pest has been poorly understood. Javier Ceja-Navarro, Eoin Brodie and colleagues at Lawrence Berkeley National Laboratory in the United States found that samples from seven major coffee-producing countries had a common core microbial population in the gut, including specific Pseudomonas aeruginosa.

Caffeine usually acts as a powerful insecticide. the experiment of using antibiotics to inactivate the intestinal microflora of coffee fruit beetle will make the pest lose its ability to detoxify caffeine. as a result, the number of viable pests decreased significantly compared with the control group. Moreover, coffee beetle pests treated with antibiotics were re-inoculated with one of the pseudomonas strains from their intestines, so that these pests could feed on coffee again. The findings may help develop new biological control methods that target intestinal microbes that enable coffee beetles to survive on caffeine-rich foods.