A research team led by Fu Xinhua, a professor from Huazhong Agricultural University (HZAU), in collaboration with Li Daiqin, professor from Hubei University and Zhang Shichang, associate professor from the same university, discovered that the common web-building spider, Araneus ventricosus, can manipulate the flash signals of fireflies to lure them.

The research results were recently published in the international journal Current Biology.

"Our previous study showed that many fireflies caught in spider webs were male, which piqued our interest," Fu said.

Typically, male Abscondita terminalis fireflies use two light organs to emit multiple pulses of mating signals. However, when these male lightning bugs are captured and injected with toxins by Araneus ventricosus, they use only one light organ, mimicking a single-pulse female mating signal, thereby attracting more males to the web.

Araneus ventricosus uses captured Abscondita terminalis males to lure more fireflies. [Photo/news.hzau.edu.cn]

Further research revealed that when normal male Abscondita terminalis fireflies were placed in a spider web, Araneus ventricosus displayed typical manipulation behavior and patiently waited for the prey to get caught. In contrast, male fireflies with their light organs painted black were immediately consumed by the spiders without any manipulation. The manipulated males attracted more of their kind to the web, compared with those not manipulated.

"Spider toxins might affect the fireflies' neural system that controls flash signals. By injecting toxins into the males and predisposing their flash signals to mimic those of females, spiders can attract more prey," Fu explained.

The research team speculates that despite their limited vision, web-building spiders can detect firefly flash signals and use this information to develop different predation strategies. The ability to manipulate firefly flash signals may be an evolutionary adaptation.