Spider web and silk performance landscapes across nutrient space.

Area of Science:

• Behavioral Ecology
• Arachnology
• Biochemistry

Background:

• Predators often adjust foraging based on recent feeding history.
• The regulatory mechanisms of trap-building predators, specifically orb web spiders, remain largely unexplored in relation to their feeding history.

Purpose of the Study:

• To investigate whether orb web spiders (Nephila pilipes) modulate their web and silk properties as a regulatory strategy in response to differential nutrient extraction.
• To explore the plasticity of web architecture, silk properties, and web tension based on spiders' nutritional history.

Main Methods:

• Orb web spiders (Nephila pilipes) were fed different diets (live crickets, dead crickets with stimulated webs, or dead crickets without stimulation) for 21 days.
• Measurements included nutrient extraction, web architecture, silk tensile properties, silk amino acid composition, and web tension.
• Web and silk 'performance landscapes' were plotted across nutrient space.

Main Results:

• Nephila pilipes demonstrated plastic adjustments in the chemical and physical properties of their webs and silk.
• Performance landscapes for web and silk parameters exhibited multiple peaks and troughs, indicating complex responses to nutritional history.
• Nutrient extraction varied based on the feeding regimen.

Conclusions:

• Orb web spiders plastically adjust web and silk properties according to their nutritional history.
• The study expands the application of geometric framework foraging models to include trap-building predators.
• Further research is needed to determine if these findings apply to other predatory traps.