The Mariposas were a movement dedicated to providing medical care to those in need. It was founded on Earth in the 21st century by Doctor Teresa Ramirez and Cristóbal Rios, a former Starfleet captain who had time traveled from 2401 to 2024. Its name (meaning "butterfly" in the Spanish language) and logo were derived from the Clinica Las Mariposas, Ramirez's former clinic in Los Angeles.
In 2401, Guinan described the work of Rios and Ramirez with the Mariposas to Admiral Jean-Luc Picard, after Picard had been returned to his original time by Q. (PIC: "Farewell")
Also that year, Seven of Nine was transporting Mariposa-labeled medical supplies for the Fenris Rangers on La Sirena when the ship was attacked by pirates. (PIC: "The Star Gazer")
The medical vessel SS Eleos XII, operated by Doctor Beverly Crusher and her son Jack Crusher in the early 25th century, was affiliated with the Mariposas. (PIC: "Disengage")
According to the production art for the Eleos, the full name of the organization is the "Mariposa Medical Group". [1]