Adults fly in one generation in winter, from December to April, during which they do not eat. They are attracted to lights, but normally females will remain stationary and emit a pheromone to attract males. and probably
Clarkia purpurea,
Camissonia bistorta and
Camissonia strigulosa. In later
instars they lose the horn that characterizes most sphinx moth caterpillars, and instead have a "bullseye" spot. The caterpillars can reach 5 cm. The caterpillars begin to pupate four to five weeks after hatching. They will pupate under leaf litter or burrow up to 16.5 cm down into the root mass of their host plants, and wait until next winter to eclose (emerge). ==References==