Prey bioluminescence-mediated visual luring in a sit and wait predator.

Area of Science:

• Ecology
• Animal Behavior
• Predator-Prey Dynamics

Background:

• Sit-and-wait predators often employ deceptive strategies due to high energetic costs of behavioral and physiological processes.
• Sheet-web spiders (Psechrus clavis) are known to use visual cues for luring prey.
• A unique observation involves P. clavis retaining fireflies (Diaphanes lampyroides) after capture, allowing them to continue signaling.

Purpose of the Study:

• To investigate if Psechrus clavis spiders exploit the bioluminescent signals of captured fireflies to attract additional prey.
• To test the hypothesis that this prey-handling strategy enhances foraging success by using the prey's signal as a deceptive lure.

Main Methods:

• A field manipulative study was conducted using light-emitting diodes (LEDs) to simulate firefly bioluminescence.
• The response of fireflies and other potential prey to the simulated signal was evaluated.
• Infrared video cameras were used to record prey attraction and interception rates in P. clavis webs.

Main Results:

• The simulated firefly signal significantly increased prey attraction and interception rates within spider webs.
• Male Diaphanes lampyroides constituted the majority of the additionally captured prey.
• This strategy enhances foraging returns for P. clavis.

Conclusions:

• Psechrus clavis spiders effectively exploit the bioluminescent signals of captured fireflies to lure more prey.
• This behavior provides a unique foraging advantage for nocturnal sit-and-wait predators.
• The strategy may allow spiders to reduce investment in other prey-attracting adaptations, such as body coloration.