Do some spiders take advantage of fireflies’ glowing signals to lure more prey?

“The signals produced by male fireflies in spider webs looked similar to those produced by independent females.” File | Photo credit: Getty Images

Fireflies rely on glowing signals to communicate with other fireflies using light-emitting lanterns on their abdomens. abscondita terminalisMales make multi-pulse flashes from two lanterns to attract females, while females make single-pulse flashes from one of their lanterns to attract males. Researchers now have evidence that a circle-weaving spider (Araneus ventricosus) manipulate the flash signals of male fireflies trapped in their webs in such a way that they mimic the usual flashes of female fireflies, and thus lure other males to be their next meal. The researchers suspected that the spiders might attract males to their webs by somehow manipulating their flashing behavior. During field experiments, they found that the spider’s webs more often trapped male fireflies when a spider was present. The signals made by male fireflies in webs with spiders looked very much like the signals made by free females. Specifically, the trapped males used single-pulse signals using one of their lanterns, not both. The findings suggest that the males are not changing their flashes as a sign of distress.