Spiders turn male fireflies into bait for new victims

A recent study by an international team of biologists from China, Singapore, Kenya and Slovenia has revealed an amazing example of predatory agility.

Spiders of the species Araneus ventricosus, which live in China, Japan and Korea, have learnt to use the light signals of male fireflies to attract new victims into their nets.

The results of the study were published in the journal Current Biology.

Abscondita terminalis fireflies use bioluminescence to communicate and attract mating partners. However, the scientists noticed that it was males, not females, who were more likely to be caught in the webs of Araneus ventricosus. This led the researchers to speculate that the spiders could somehow manipulate the light signals of their victims.

The biologists conducted field experiments observing 161 webs. They recorded an interesting behaviour: when the spider captured a male firefly, the latter continued to emit light signals. After the spider bite, the nature of the firefly's glow changed - it became similar to the signals of females, attracting other males.

Thus, the victims were turned into baits that lured new fireflies into the web.

The researchers noted that more male fireflies were caught in the web in the presence of the spider than in its absence. It is not yet clear whether it is the spider's venom or its bites that causes the light signals to change in the captured males. These details will be explored in future studies.

The authors also suggest that similar strategies may be common among other predators that use victims to attract new prey.