Hey need the exact location that you need to defeat in order to get their spinnerettes. This is given by Milaka upon the 3rd time you talk to her in the house on the upper crystal grove after you initially freed her
sorry but that statement made by colagada isn't accurate. Since I'm the original poster of this post I need to clarify. I came to find out (after some trial and error on my part) that the regular crystal spiders won't do because they don't spawn the spinnnerettes. However the ancient spiders do spawn them. So to clarify, any wizard doing the sit and spin quest, go after the ancient spiders. FYI make sure you have tons of fire based spells also or a lot of shield spells. It took me 12 tries to finally complete that quest because the spiders are of ice school (meaning they are resistant to cold based spells) plus they get multiple attacks each one doing an avg. of 500 points of damage per hit.