Fireflies, guardians of summer insects, communicate with other fireflies using their glowing abdomens. Males of this species Abscondita terminalis Spiders attract females by emitting multiple pulses of light from both lanterns; females emit a single pulse from one lantern. But a new study finds that some spiders may be able to decode this signal and use it to their advantage. The study was published in the journal Nature on August 19th. Current Biology.
A spider spinning a spider web (Giant Isopod) manipulates the flashing signals of male fireflies to mimic the typical flashes emitted by female fireflies when trapping them in their nests. These false flashes lure other males into the nest, where they become the spider’s next prey. But it’s not yet clear whether it’s the spider’s venom or the spider’s bite itself that manipulates the firefly’s signals.
[Related: A new theory on why fireflies glow—and why they need help.]
The discovery came when Fu Xinhua, an entomologist at China’s Huazhong Agricultural University and co-author of the study, observed several male fireflies entangled in spider webs while working in the field. He rarely saw female fireflies entangled in webs, and additional field surveys revealed this sex-biased pattern. Fu hypothesized that the spiders might somehow manipulate the fireflies’ behavior to attract other fireflies.
To Testing this hypothesis To support his hypothesis that spiders are manipulating the firefly signals, he brought in behavioral ecologists Li Daqin and Zhang Shichang from Hubei University. Field Experiments So the researchers observed the firefly signals and the spiders’ behavior and found that male fireflies were caught in spider webs more frequently when the spiders were present on the web than when they were away from it.
Further analysis showed that the signals produced by male fireflies in spider webs were similar to those produced by free-flying females: captive males used a single-pulse signal using only one lantern, rather than both.
Interestingly, captive male fireflies rarely lure other males out when they are alone in the nest and no spiders are nearby, suggesting that the males are not altering their flashes as some kind of distress signal. The team thinks that the spiders are altering the firefly’s signals.
“Spider eyes generally have limited spatial awareness, but they rely more on temporal awareness than spatial awareness to identify flash signals.” Li said in a statement.“Upon sensing the light-emitting signals of a captured male firefly, the spider performs a specialized prey-disposal procedure that involves repeated wrapping and biting attacks.”
[Related: Spider glue might evolve faster than the spiders themselves.]
According to the teamThe experiments reveal that some animals can use indirect but dynamic signaling to target very specific types of prey in nature. The team also believes that there are many unexplored examples of this type of mimicry in nature, waiting to be discovered. Predators may use visual signals as well as sound, pheromones and other methods to fool their prey. This ability to deceive is not limited to the animal kingdom: South African daisies appear to trick flies into mating and spreading pollen.
“We suggest that the light signals of captured male fireflies induce the spider to adopt a specialized prey-disposal procedure based on repeated wrapping and biting attacks,” the team wrote in the paper. “We also hypothesize that neurotransmitters in male fireflies may generate the female-like blinking pattern.”
However, more research is needed to determine exactly what is changing the blinking patterns of captive fireflies.
