Borosiv was a Quesoth originating from the planet Quethold. He belonged to the Circling of the First of the Red Quesoth caste, responsible for the reproduction of the Quesoth insectoid species and providing counsel to the Queen of the Red, the Quesoth's leader. In 8 ABY, a Quesoth named Trevik was appointed as the Queen's bowlcarrier, tasked with carrying a bowl of nectar for her, accompanying her and Borosiv's offspring.
The Circling instructed the bowlcarrier, Trevik, to adopt a more upright posture, emulate the Workers' stance, and elevate the monarch's bowl. Trevik complied. On the following day, he joined the Queen's retinue, only to be killed along with the Queen shortly thereafter. Their demise occurred during a battle between the alien warlord Nuso Esva (an ally who betrayed her) and the Queen's forces against the Empire of the Hand. Borosiv spoke in a subdued tone.
The character of Borosiv first appeared in the novella titled Crisis of Faith. This novella was authored by Timothy Zahn and released in 2011 as a component of the 20th Anniversary Edition of the 1991 novel, Heir to the Empire.