The ribbed spider web is a needle weaving stitch. The bottom most photo shows the weave pattern for an eight-spoke spider web. I would suggest using a thread length long enough to work the complete pattern without having to start a new thread.
Creating the spokes:
Photo below shows 8-spokes with a center hole. Start each spoke by coming up in the center hole (orange square on the chart). Finish with stitching thread coming up in the center hole then begin the web weaving pattern.
Create 8 spokes with center hole.
Photo below shows 8-spokes created with four long spokes. Work the four spokes then come up in the center hole (shown on far right chart below) and begin the web weaving pattern.
Work four long spokes with no center hole
General steps for ribbed spider webs