Leptothrips fasciculatus (Crawford) is a tubuliferan thrips that has primarily been collected as adults from Eriogonum fasciculatum Bentham, a shrub that produces compound inflorescences with flowers in clusters. I observed, collected, and photographed adults and immature stages of the thrips on inflorescences of Eriogonum fasciculatum polifolium (Bentham) Torrey & A. Gray in the Mojave Desert during spring 2011 and 2012. Adults moved intermittently around the outside of inflorescences. Eggs were located, and first- and second-instar larvae were abundant, inside flowers and within the involucres that surround flower clusters. Mature second-instars and non-feeding fourth- and fifth-instars inhabited leaf litter and soil beneath plants. Eggs were subcylindical, translucent, without reticulation, and knobbed on one end by an aeropyle. Second-instar larvae were red with a median, yellow band. Adults and larvae were observed feeding on pollen and other flower parts but not prey. Leptothrips fasciculatus's anthophilous behavior contradicts the predation generalized for the genus.