Long-scale, multi-generational migration is instrumental in the
devastating potential of locust swarms as a major agricultural pest. Gut
bacterial symbionts have been shown to augment locust immunity, and to
support locust swarming via the emission of attracting volatile
compounds. To date, however, it is unclear whether and how those
beneficial symbionts are transmitted vertically through generations.
Using comparative 16S rRNA amplicon sequencing and genetically-
engineered bacteria, we demonstrate here for the first time
transgenerational-transmission of gut bacteria in the desert locust, as
well as its underling mechanism: females inoculate bacteria into the egg
pod’s foam-plug, through which larvae pass upon hatching. in addition to
chitin, which is its primarily component, we show the foam to also
contain bactericidal proteins, such as lysozyme that select for specific
bacteria. These findings reveal for the first time the mode of
transgenerational-transmission of symbionts in locusts, potentially
contributing to the swarms’ migratory success.