Thousands of years before it was discovered, the Descoladores sent robotic probes from the planet, carrying prototypes of the Descolada virus. Eventually, a probe was sent to Lusitania and destroyed the ecosystem of the Pequeninos' homeworld.
Children of the Mind
Jane theorized that the evidence of various Descolada-like viruses in planets had emanated in a cone shape from the Descoladores' homeworld. She took Valentine Wiggin II and Miro Ribeira to the planet when they were searching for possibly habitable worlds. 
Later, an exploratory team was sent to orbit the planet and learn their language. Eventually, the team was noticed by the Descoladores and they sent transmissions to their ship. After a ship was sent out from the planet to approach the exploratory team, they retreated to Lusitania.