The term "Shaivite" is overused nowadays. For instance, Iyer Brahmins are often called Shaivites, but they're actually followers of Adi Shankaracharya's Smartha sect (which I discuss here and here), and simply adopt Shiva as their Ishta Devata. True philosophical Shaivism is relatively rare nowadays (in contrast to philosophical Vaishnavism which is pretty common). I discussed one genuine Shaivite sect, the Lingayat sect of Basava, in my answer here. But my question is related to a more famous sect of Shaivism, known as Shaiva Siddhanta, which is based on the Shaiva Agamas and the poems of the Nayanars just as the Sri Vaishnava sect (of which I'm a member) is based on the Pancharatra Agamas and the poems of the Alwars.
In any case, one of the defining works of the Shaiva Siddhanta sect is Meykandar's Shiva Jnana Bodham, a commentary on twelve important verses from a Shaiva Agama called the Raurava Agamas. Now Meykandar's shishya Arulnandi Shivacharya wrote a work called the Shivajnana Siddhiyar, which is a commentary on Meykandar's work but also tries to refute rival schools of philosophy. In this excerpt from the Shiva Jnana Siddhiyar, Arulnandi Shivacharya refutes the Purva Mimamsa philosopher Kumarila Bhatta's belief that souls are always reborn into the same species:
You say that of living beings, both moveable, and immovable, each of them will only change its body at its rebirth, according to its respective karma, but not its form. But answer me first, whether when humans enter Svarga and partake of the bliss therein, whether they do so there as human beings or as celestials? If they enjoy heaven as mere human beings, then this heaven ceases to be such. If as celestials they enjoy, your theory that they do not change their forms falls to the ground. After enjoying as celestials, when they are reborn on earth, they will only be reborn as human beings and not as celestials.
Some worms become beetles and some worms become wasps. Similarly beings change their forms according to their Karma. Most of the schools are also agreed on this point, and why should you alone have doubts about it? The accounts of Agalya becoming a stone, of Mahavishnu incarnating in several forms, of a spider being born in the Solar Race of far famed kings, and a rat having become Mahabali, also demonstrate our point.
Now most of these stories are recognizable: Gautama cursing his wife Ahalya to turn to stone, Vishnu's incarnations, and the story of a rat being reborn as Mahabali which is attested at least in folk tales? But my question is, what is the story of "a spider being born in the Solar Race of far famed kings"?
Is this a case of a solar dynasty king being cursed to turn into a spider, or a solar dynasty king having a spider as a son, or what? Are there any scriptures which mention this story?