Soil pH constrains Burkholderia symbiont acquisition in stink bugs (microbiomejournal.biomedcentral.com)

• Six stink bug species (Coreoidea and Lygaeoidea) depend on soil-borne Burkholderia for growth and reproduction.
• Soil pH <7 enables symbiont acquisition; pH≥7 suppresses it by reducing bacterial abundance and flagellar motility.
• Experimental pH manipulation with CaCO3 confirmed causal link; motility loss observed within hours at high pH.

"Research published in Microbiome (May 2026) demonstrates that soil pH acts as an external filter for the establishment of gut symbiosis between stink bugs and Burkholderia bacteria. Field surveys and laboratory experiments with six stink bug species from Japan revealed that symbiont acquisition is efficient in mildly acidic soils (pH<7) but severely impaired in neutral to alkaline soils (pH≥7). The mechanism involves both reduced Burkholderia abundance and loss of flagellar motility at high pH, preventing bacteria from passing through the insect's gut constricted region. This shows that abiotic soil properties can shape host-microbe interactions before colonization, with implications for insect population dynamics and pest management."