Fireflies rely on flashing signals to communicate with other fireflies using light-emitting lanterns on their abdomens. In fireflies of the species Abscondita terminalis, males make multi-pulse flashes with two lanterns to attract females, while females make single-pulse flashes with their one lantern to attract males. Researchers now have evidence that an orb-weaving spider (Araneus ventricosus) manipulates the flashing signals of male fireflies ensnared in its web such that they mimic the typical flashes of a female firefly, thereby luring other males to serve as their next meal. Researchers suspected that the spiders might be attracting males to their webs by somehow manipulating their flashing behaviour. During field experiments they found that the spider’s web more often captured male fireflies when the spider was present. The signals made by male fireflies in webs with spiders looked a lot more like the signals of free females. Specifically, the ensnared males used single-pulse signals using only one of their lanterns, not both. The findings suggested that the males weren’t altering their flashes as a distress signal. The researchers propose that the spiders alter the firefly’s signal.
