Thrips are believed to have descended from a fungus-feeding ancestor during the Mesozoic, and many groups still feed upon and inadvertently redistribute fungal spores. These live among leaf litter or on dead wood and are important members of the ecosystem, their diet often being supplemented with pollen. Other species are primitively eusocial and form plant galls and still others are predatory on mites and other thrips. Two species of "Aulacothrips", "A. tenuis" and "A. levinotus", have been found to be ectoparasites on aetalionid and membracid plant-hoppers in Brazil.