The Vespid are a unique race of insect-like aliens who are members of the Tau Empire. In the Tau Lexicon, they are called "Mal'kor". This derives from the Tau words for insect, "Mal," and air, "Kor." The Vespids' homeworld is a gas giant also called Vespid, three light years to the galactic south of the Tau's D'yanoi Sept. The Vespid live in "stalagmites", floating islands that are similar to Terran termite mounds. These islands float above the violet, storm-blasted planet with lighter-than-air gases, and deep on the planet's hazardous surface, the Vespid females dive to collect the crystals to create the neutron blasters of the Stingwing forces. Upon first contact, the Vespid and the Ethereal Caste were unable to to communicate very extensively until the Earth Caste could create a device, now called the Communion Helm, that opened channels of communication for both races. Vespid forces working with the Tau are organized into squads called Stingwings. Using their diamond-hard claws and Neutron Blasters to harass enemy heavy infantry, like Space Marines. The Stingwing commanders, called "Strain Leaders", wear Communion Helms, gifted to them by the Ethereal Caste, which allows them to keep in contact with both Shas'Ar'Tol command and the other members of the Strain. The Vespid, unlike the mercenary Kroot, fight for the Greater Good alongside their Tau allies, which brings a sort of camaraderie to the Tau Empire's forces that the Kroot do not share.
- Codex: Tau (3rd Edition)
- Codex: Tau Empire (4th Edition)