New acoustic tech detects how common pesticides harm ant colonies
Researchers have developed a non-invasive sound-monitoring method that reveals pesticide damage to soil insects at environmentally realistic levels—damage that was invisible to existing detection tools. The breakthrough could reshape how companies and regulators assess the real-world impact of widely used neonicotinoid pesticides on critical soil ecosystems.
Originaltitel: Using sound to detect <i>Formica rufa</i> behavioural changes to a common pesticide
**Akustisk övervakning avslöjar neonikotinoid-skador på myror redan under miljöreleveanta doser** Metod för att tidigt detektera pesticidbuskador på mark-levande insekter har saknats. Svenska forskare vid Umeå universitet demonstrerar att ljudinspelningar kan avslöja subletala beteendeförändringar i rödmyrkoloniers (Formica rufa) aktivitet orsakade av imidakloprid. Kolonier exponerade för miljöreleveanta imidaklopridhalter (10,8 ± 5,7 ng g⁻¹) visade ökad aktivitet inom sex timmar, följt av långsam återhämtning över en vecka. Metoden lyckades upptäcka denna långtidseffekt trots myrornas underjordiska miljö — något andra tekniker missat. Forskargruppen inkluderade Svenska lantbruksuniversitetet, NORCE Research AS och Species360. Akustisk övervakning möjliggör icke-invasiv fältövervakning av skadliga effekter och kan bli ett verktyg för regulatorisk miljötestning av kemikalier. Resultaten väcker frågor om neonikotinoidernas påverkan på pollinerare och markekosystem vid låga expositionsnivåer.
Abstract Soil-dwelling insects may be at particularly high risk of exposure to pesticides because soils are a major recipient of these chemicals. Still, we lack non-invasive techniques to detect in situ responses of soil macrofauna to pesticides and other contaminants. Here, we test if sound recordings can reveal sub-lethal behavioural shifts in ant colonies caused by a neonicotinoid (imidacloprid). We demonstrate that an acoustic variable can detect pesticide-induced shifts in outdoor behaviours (increased activity) of red wood ants (Formica rufa). This behaviour shift was observed at environmentally relevant, sub-lethal levels of imidacloprid (10.8 ± 5.7 ng g−1 sample, average ± standard error). Notably, our recordings revealed a short-term (&lt;6 h) increase in activity induced by the pesticide, followed by a slow recovery and a return to the baseline over a weekly timescale. The long-term sub-lethal behavioural effects would have been difficult to detect using other techniques, given the opaque nature of the studied mounds. We conclude that acoustic monitoring offers a promising tool for detecting pesticide effects in natural settings. We also provide recommendations for best practices for acoustic monitoring of soil fauna and discuss the challenges of measuring soil fauna behavioural changes in a natural setting.