Beewolves Coat Cocoons With Antibiotic Cocktail

Source: Johannes Kroiss and Martin Kaltenpoth, MPI for Chemical Ecology

Thursday, March 4th, 2010--

Beewolves are solitary wasps that build underground nests in sandy soil in Europe, the United States and Northern Africa. As the cocooned larvae develop, females provide them with paralyzed honeybees for nutrition. Now researchers in Germany report that the wasps also endow their offspring with a protective coat of antibiotic-producing bacteria.

Beewolf females cultivate the bacteria in specialized glands in their antennae and secrete them into the brood cell, the compartment where larvae are housed. After the larvae are deposited into the cell – in a process called oviposition – they take up the bacteria and move the bacteria to the walls of their cocoon.

Scientists had previously shown that these secreted bacteria helped the wasps fend off infection – common in the warm, humid conditions of the nest – but had only theorized how they did it. Now, researchers at the Max Planck Institute for Chemical Ecology in Germany have shown that the bacteria are producing antibiotics. Their current study, in this month’s Nature Chemical Biology, characterized 9 different types of antibiotics produced by the bacteria, all from the Streptomyces genus. Streptomyces bacteria are most commonly used in human medicine to produce antibiotics such as chloramphenicol, tetracycline and streptomycin.

“This research shows that not only humans use antibiotics produced by bacteria to protect themselves against pathogen infections,” says Martin Kaltenpoth, a lead author of the study. “Insects have evolved symbioses for this purpose a long time ago.”

While the beewolf larvae enjoy protection from harmful pathogens, the bacteria benefit by obtaining an unoccupied ecological niche. The scientists believe that the study of these species may lead to the discovery of new drug candidates for human medicine.

“If we gain a better understanding of such interactions and how they effectively protect the insect host against pathogens over millions of years, we might learn a lot for human medicine as well,” Kaltenpoth told Science Friday.

The research is being conducted by a team at the Max Planck Institute for Chemical Ecology, the University of Würtzburg and the University of Regensburg, all in Germany.

- Aleszu Bajak