Orb-web building spiders are excellent models for investigating the interaction of foraging behavior and physiology.  Unlike many animals, there is a physical, measurable record of the foraging investment made by an individual:  the orb web.  Nephila clavipes, like many orb-weaving spiders, spins a partially or entirely new orb web each day.  (The barrier webs, which block some predators from approaching the spider, are not renewed).   The size of the orb web built by a spider increases as the spider increases in size, and the rate of increase depends upon how much food a spider is capturing.  Very well fed spiders and nearly starved spiders  build smaller orb webs;  apparently because the former group doesn't need to invest in foraging, and the latter group cannot.  The largest orb-webs are built by spiders capturing moderate amounts of prey. What makes the orb web even more interesting as a foraging strategy is that the spiders must synthesize this web from materials that might be used for growth and development.  One component of the N. clavipes orb web, choline, is physiologically important and a nutritional essential (not synthesized by the spiders).  Choline is a precursor for cell membrane components and the neurotransmitter acetylcholine, and is apparently required to make the orb-web sticky.  Juvenile N. clavipes under nutritional stress make trade-offs in choline allocation between foraging investment and growth.

  N clavipes in captivity with moth