Solubility of white phosphorus
White phosphorus has P4 molecules packed into a crystal,these dissolve readily in Carbon Disulfide.



Whereas Red phosphorus is polymeric in nature. It is a derivative of white phosphorus where one P-P bond is broken and an addtional bond is formed with neighboring tetrahedron molecule resulting in a chain like structure .



Like all long chain polymers this will lower its ability to dissolve and its solubility in solvents