This dosen't tell us anything about why the scorpion flouresces, it just seems to be an overall description of the animal from a field guide.The striped scorpions body is covered with a waxy cuticle that helps prevent dessication. The scorpion cuticle flouresces under ultraviolet light, which helps when collecting or observing them at night. (Drees & Jackman 1998)"
Most terrestrial arthropods have a waxy covering that prevents water loss. This is seperate from the cuticle, which is what flouresces in scorpions.