Ethanol traps used for collecting leaf litter and moss-inhabiting flea beetles A–C regular ethanol traps were placed close to moist moss, liverwort, or leaf litter to collect flea beetles D, E modified ethanol trap for collecting living individuals; diagram in inset E shows that ethanol-dipped sponge is used as bait, the upper opening of the bowl is sealed by plastic film leaving a narrowing opening for beetles to crawl in, the plastic film forms a slope; when the flea beetles try to escape, they usually crawl upwards and could be trapped by the slope.