These butterflies are known for their almost complete dependence upon Kearney buckwheat; eating the fallen leaves of the plant as larvae, and drinking the nectar of the flowers as adults - however, the adults occasionally feed on other plant species. Like many gossamer-winged butterflies, Sand Mountain blues have a close relationship with ants; in this case, desert carpenter ants feed on a sugary secretion of the larvae; whether the larvae also benefit or not is yet to be determined. Once the larvae metamorphose into the pupal stage, rather than remaining fixed to buckwheat plant, the chrysalis drops into the leaf litter at the base. Upon reaching adulthood, E. pallescens arenamontana typically measure anywhere between and . The subspecies is not known to migrate, and stays within of its host plant. The lifespan of an adult Sand Mountain blue is approximately one week.