To the point:

• Within a short period of time, the reed leafhopper has evolved from a reed grass specialist to a dangerous pest that attacks sugar beets, potatoes, carrots, onions, and other crops.
• It lives in close association with a community of seven different bacteria, harboring them in various organs. Two of these bacteria transmit plant diseases that can lead to massive crop failures.
• On the other hand, symbiotic bacteria likely play a key role in enabling the leafhopper to expand its host range successfully.
• The findings will help to develop new, targeted control strategies based on influencing beneficial or harmful bacteria.

 

The reed leafhopper (Pentastiridius leporinus) was originally a specialist, limited exclusively to reed grass as a food source. Within a few years, however, it developed into a dangerous pest that attacks not only reed grass but also sugar beets, potatoes, carrots, and onions. It does not directly damage plants, but it transmits deadly bacteria that lead to massive crop failures, especially in sugar beet production. Two bacterial pathogens are responsible for this: one causes SBR (Syndrome Basses Richesses, or low sugar content syndrome), and the other causes stolbur.

Researchers from the Max Planck Institute for Chemical Ecology in Jena and the Fraunhofer Institute for Molecular Biology and Applied Ecology in Giessen investigated how this insect spread so rapidly and what role its microbial flora might have played in the process. The researchers used state-of-the-art sequencing methods and fluorescence in situ hybridization to identify the microbial community and show where it resides in the insect's body.

"We showed that the reed leafhopper hosts at least seven species of bacteria. The leafhopper appears to be completely dependent on three of these species. These symbionts inhabit specific organs and are passed down through generations alongside the eggs. The bacteria contribute to the leafhopper's nutrition by producing essential amino acids and vitamins. Two other bacteria cause the plant diseases SBR and stolbur. These pathogens are transmitted from leafhoppers to host plants, contributing largely to the harmful effects of leafhoppers. The significance of the two remaining bacteria remains unclear," says lead author Heiko Vogel, summarizing the most important findings. Vogel heads the Host Plant Adaptation and Immunity project group in the Department of Insect Symbiosis.

The two plant-pathogenic bacteria are Candidatus Arsenophonus phytopathogenicus, which causes SBR, and Candidatus Phytoplasma solani, which causes stolbur disease. The research team found five other bacterial species in various organs of the reed leafhopper. The genera Purcelliella, Karelsulcia, and Vidania are mutualists that enable a plant-sap diet. These genera compensate for nutritional deficiencies by providing essential amino acids and B vitamins, or by contributing to the biosynthesis of these substances. The significance of the genera Rickettsia and Wolbachia for the insect host remains speculative. "We were particularly amazed by the complexity of the different microbes, as well as by the fact that Rickettsia bacteria can be found in the cell nuclei of many leafhopper tissues," says Martin Kaltenpoth, head of the Department of Insect Symbiosis at the Max Planck Institute.

 

“We suspect that the leafhopper's ability to expand its host plant spectrum is due to interactions between the different types of bacteria.” Heiko Vogel

 

The results of the study serve as the starting point for developing targeted strategies to manipulate the reed leafhopper's bacterial symbionts. One approach is to inhibit the production of specific salivary proteins in the leafhoppers using RNA interference. Double-stranded RNA (dsRNA) is injected against the target gene to accomplish this. "We are currently developing dsRNA-based sprays in Giessen for the environmentally friendly and targeted control of reed leafhoppers and other pests," says Andreas Vilcinskas from the Fraunhofer Institute for Molecular Biology and Applied Ecology.

Further studies are planned to better understand the role of the reed leafhopper's microbial partners and their interactions. These studies should reveal new approaches to combating this devastating agricultural pest.

 

Publication:

Vogel, H., Weiss, B., Rama, F., Rinklef,A., Engl, T., Kaltenpoth, M., Vilcinskas, A. (2025).

A multi-partner symbiotic community inhabits the emerging insect pest Pentastiridius leporinus.

mBio 0:e03103-25. https://doi.org/10.1128/mbio.03103-25

 

Further Information:

Dr. Heiko Vogel, Max Planck Institute for Chemical Ecology Department of Insect Symbiosis, Hans-Knöll-Straße 8, 07745 Jena, Germany, Tel. +49 3641 57-1512, E-Mail hvogel@ice.mpg.de

Prof. Dr. Martin Kaltenpoth, Max Planck Institute for Chemical Ecology Department of Insect Symbiosis, Hans-Knöll-Straße 8, 07745 Jena, Germany, Tel. +49 3641 57-1500, E-Mail kaltenpoth@ice.mpg.de