Springtails feeding on a wheat pathogen fungus: a possible bioregulation of inoculum sources?

Septoria leaf blotch, caused by Zymoseptoria tritici, is a foliar disease that affects wheat crops. Between growing seasons, the fungus survives in wheat residues left on the soil. This phase is often overlooked in epidemic risk management, yet reducing inoculum sources can have a limited effect on the timing of septoria attacks. In this study, Thomas Bourgeois and his collaborators tested the potential of Heteromurus nitidus, a springtail species found in soils and known to interact with various fungal species, as a potential bioregulator of Z. tritici.

"Choice" and "consumption" experiments were conducted on contaminated wheat residues from leaves inoculated with the fungus. The springtails "grazed" the fruiting bodies of Z. tritici (pycnidia) and reduced the number of spores (by a factor of ten) compared to control residues that had not been exposed to the springtails. The attractiveness of contaminated residues and the reduction in pycnidiospore numbers indicate that, under controlled conditions, Z. tritici serves as a food source for H. nitidus. Could this springtail species contribute to the bioregulation of septoria inoculum sources in the field? This is the question raised by the results of this study.

The application perspectives depend on the ability of H. nitidus populations, or even other springtail species, to interact effectively with Z. tritici during key epidemic stages. This research continues within the framework of a maturation project led by MNHN* and funded by SATT LUTECH.

Bourgeois T, Prado S, Suffert F, Salmon S. 2024. The collembolan Heteromurus nitidus grazes the wheat fungal pathogen Zymoseptoria tritici on infected tissues: opportunities and limitations for bioregulation. Pest Management Science, sous presse https://doi.org/10.1002/ps.8026

* Muséum National d'Histoire Naturelle