Dasypyga alternosquamella is a species of snout moth in the genus Dasypyga. It was described by ÃÂmile Louis Ragonot in 1887 and is known from western North America.
The larvae feed exclusively on dwarf mistletoe (Arceuthobium) species, including Arceuthobium vaginatum subsp. cryptopodum and Arceuthobium campylopodum. Early in their development (first instar), larvae feed on the flowers and tips of dwarf mistletoe shoots, and in later stages they mine into the shoots, eating the mistletoe from within. Since the larvae mine from the base of mistletoe shoots, herbivory generally kills the plant, and large populations of D. alternosquamella can dramatically impact dwarf mistletoe ecology. The larvae are highly variable in color, depending on the color of the mistletoe shoots they feed on.