In 2268, Loskene intercepted the USS Enterprise, ordering it to leave Tholian space. The Tholians allowed the Enterprise an hour and fifty-three minutes, which the starship required to potentially rescue James T. Kirk, who was lost in spatial interphase.
When the allotted time expired and Loskene opened fire on the Enterprise, the Enterprise returned fire, temporarily disabling Loskene's ship. They called for reinforcements and proceeded to form a Tholian web around the Enterprise. Before the web was completed, the Enterprise was able to escape and they were defeated. (TOS: "The Tholian Web")
The character appeared in Peter David's Pocket TNG novel Vendetta where he was present at the border patrol that intercepted the planet killer under the command of Delcara. His ship was disabled and approached by the USS Enterprise-D, where he inquired whether a 'lying Vulcan called Spock' was present among the crew. After which, he warned the Starfleet ship to leave their territory while they dealt with the doomsday weapon trespassing Tholian space.
The alternate reality version of the character appeared in the "fourty-seventh" issue of the Star Trek: Ongoing series. The script's cast list calls the character "Locene", while the rest of the script uses the spelling "Loskene".